After 3 days in the OR, my '84 XJ 2.5 w/YFA & 4spd starts, idles, runs, and SMELLS better. Having searched in vain for a clear, concise, one stop tech article, I've written my own. This is for everyone with an AMC 2.5 4 cyl. w/ a Carter YFA carb and the full PulseAir (P/A) emissions package.WARNING! If you live in an emissions testing state, there is NO WAY it will pass or be "street legal". However, if you do not, or if your XJ is "off road" only, you have patience, some technical skill, & more time than money, this is a "how to" mod that will provide better starting, idling, running, performance and mileage. No net legends, guesswork, mystery, BS, high $ carbs, intense rebuilding, reprogramming or fabrication. It's in 5 sections, with notes & comments in section 5. I believe it has less emissions and KNOW it runs better with the P/A & it's controls removed- a system that kind of worked in '84 with '84 fuel that wasn't working now- ironic justice strikes again! This should also work on :CJ,YJ,MJ,Eagle,Pacer,or anything with an operating 2.5 w/carb.The carb mods may also work on 300 c.i. Ford sixes. I'm not sure where the auto trans gets it's vacuum signal, so you're on your own there.Check other websites and work carefully! ANOTHER WARNING! This mod will NOT fix other engine damage, worn out parts, your or PO's mistakes (or perform other miracles)- so no whining - I did say an operating (running) 2.5 !
1.THE NUTTER BYPASS: Do it exactly as his article says- it's essentially 3 wires on an XJ, plus a timing reset.Just unplug the MCU at the CDI box, and splice the distributor to the CDI harness. Don't just twist & tape wires- use terminals, then tape, then factory type split convolute looming. I call this version " PLUS" because of the carb mods on the YFA are roughly equivalent to the mixture needle disabling on a BBD. All hail John Nutter! The '84 started running better as soon as the bypass was
done, but the carb work & P/A removal is an essential part of this mod. Remember to reset the timing too, because now you can- without MCU interference.
2. THE HAL 9000 XJ LOBOTOMY: After HAL (the computer, MCU, CPU, CEC, or whatever you want to call it) is disconnected/disabled as per the Nutter bypass, the entire emissions quagmire will be non-functional (NF). This enables the removal of the PulseAir system and ALL of it's attendant hoses, valves, solenoids, wiring, etc. On the carb, the SoleVac idle control, WOT switch, and the mixture control solenoid are also eliminated.The EGR is in normal (no introduction of exhaust) mode, the catalytic converter has been gutted, and the O2 sensor has a Mv signal, but nothing to send it to. All wires, vac lines and solenoids/valves on the PCV and bowl vent were removed and all wiring harnesses and connectors stubbed and taped for later removal. My manifold heat and choke are still connected, as is TAC for heated intake air in winter. Operate the TAC from manifold vacuum. Plug all vacuum nipples not used! Exhaust manifold ports for the PulseAir were welded shut, and the cat con can be plugged or hammered/bent shut at it's P/A inlets, or removed entirely. If you want, or have to, install a new cat con ($$$), but not a used one- the monolith type catalyst element will more than likely be mostly plugged from years of overrich running. For more under hood room, and because it was NF, the cruise control actuator and vacuum cans were removed also. Redo the PCV with emission hose, not fuel line! (PCV vacuum will collapse fuel line).Fuel line is OK for the bowl vent, but make it long enough to vent gas fumes away from the exhaust manifold. Remove the carbon canister and all its hoses as well.The 4 hose temp/vac valve on the front of the exhaust manifold is NF, so remove the hoses. Knock sensor, anti-diesel relay & timer, EGR air cleaner temp, & power steering "idle up" sender are NF now also!! ALL this engine needs to run is a PCV hose and a vacuum advance hose to the distributor! Follow the Nutter Bypass by installing a new vac line from the distributor to ported vacuum on the carb- same vac nipple the factory hose was connected to, but don't reuse the factory pipe/hose/tee's, it's not getting vacuum anymore! Carefully remove all NF hoses, wire harnesses, connectors, etc. for salvage now, or tape/stub off and zip tie out of the way. Keep in mind, ALL these systems were tacked on AFTER the basic engine/carb/ignition were designed and running! See note "A".
3. THE CARB: Essentially, I've turned the feedback YFA into a YFA (YF w/automatic choke). Remove the mixture solenoid, WOT switch, SoleVac, & brackets, & tape off or remove the wiring harness. Curb idle will now be set by using a longer screw with the stock spring, it will contact the carb base like an old YF.I used the fast idle screw from another YFA. Fast idle will be set on the choke cam/counterweight. Choke setting and pulloff setting will need to be changed! Squeeze or widen the "V" in the pulloff linkage wire- that's what it's for. My mixture solenoid blockoff plate is a piece of 2mm thick aluminum using the stock gasket, with 2 spacers on the outside so I could use the stock screws.Don't use plastic unless you know it's fuel resistant! The interior carb passages for the mix solenoid are NF when the blockoff plate & bleed passage plug are installed- see next line, and fear not! With the top (air horn) of the carb removed,there is an angled bleed passage visible on the top rear wall of the float bowl for the mix control bleed- it's between the mounting bolt hole & the idle jet fuel inlet - I blocked this off with a piece of 6-32 screw wrapped in teflon tape and pushed in so it is below the mating surface to the air horn.Don't use silicone!!! Suitable diameter soft aluminum wire or epoxy may also work, but make sure the epoxy is fuel resistant & fully cured before reassembly! You have to block the bleed passage for this mod to work! I've also installed a $30 Mr.Gasket fuel pressure regulator set at 2 1/2 psi, and disposed of the inlet/outlet/return filter.Keep in mind the return filter was a "band-aid" to allow the use of the 6-8psi fuel pump! High fuel PSI=leaking needle & seat =overrich, crappy running! Plug the return line on the left inner fender, and use a inlet/outlet filter.My filter is clear so I can see when it's dirty.The plug over the idle mix needle was removed & needle set at 1 1/2 turns out, yours may vary slightly. I use a vac gage to set mixture.Higher vac = leaner mixture.Lean til it stumbles then back off til it runs smooth again. Install a new O-ring on the needle! I also cut a 11" disc of 3/16" Masonite as the top of a new taller filter (P/N below) for more intake airflow. See notes "E" and "G". Metering rod & float height were checked/adjusted also. Float height & drop are CRITICAL! The choke has been reset for winter use- drill out rivets, follow carb kit or shop manual instructions to get a baseline calibration & go from there. Don't re-rivet the choke spring housing-use screws or nut/bolt it-this makes it easier to fine tune/adjust. Choke pulloff is sourced to manifold vacuum to make sure the choke opens fully. It doesn't need to get any more technical than this. The '84 got a HyGrade carb kit by Standard Motor Products, P/N 1484 (Made in USA!) due to a hole in the acc pump diaphragm. If it needs a carb kit, and it probably does,do it now! Buy a GOOD one, not one from the auto dept. at the c-store!!! See notes "C" & "F".
4.THE RESULTS: Cold OR warm, 1 tap, 1 crank starts, pulls 18in.hg vacuum at idle, not 8-10in.hg as before.Revs to 4000+, not 2900. 950 rpm curb idle,1900 rpm fast idle. No black clouds or visible fuel spray in carb, clean plugs, smoother idle, improved driveability, more percieved power, no stumbling & hesitation, NO STINK! Mileage before:Town- 8 to 10 Hwy- 15 . Mileage after: Town-15+ Hwy-19+ (Highway MPG is an aggregate of 55mph state road, 65-70mph interstate, 55-60 intown interstate). All of this cost about $100 for wire, hose, plugs, air/fuel filters, fuel regulator, & carb kit, plus my time. I'm being conservative on the MPG figures, yours may be better, but certainly not worse.
5. RANDOM NOTES:
A. Why the HAL 9000 lobotomy reference? Just like in "2001: A Space Odyssey", the paranoiac, overcontrolling, (EPA/emissions) brain has been neutralized, leaving the very vital autonomous operating functions (fuel/air/spark) intact. No, my '84 is not named "Discovery", and I'm not Winston Smith.
B. Timing: Was set with a vacuum gage, I feel it's more accurate and indicative of engine performance.Advance is adjustable, but there are plenty of good websites that go into setting optimum advance in great detail.Make sure both vacuum & centrifugal advance are functional! Comments on vac timing are welcome, it works very well, and I've done it for decades on a multitude of engines.Any spark knock, set vacuum back 1in.hg. Dieseling isn't a problem with proper timing & fuel! For what it's worth, ignition timing is 18 degrees BTDC, total advance is 26 degrees BTDC, plug gap .035. It runs on Cenex 91 octane (10% ethanol) & 30wt(10 winter) oil quite well. See next note!
C.DON'T GET ANAL ABOUT THIS! 1.This is not about esoteric & oddball performance modifications- just reliable driveability. We're not talking recurving distributors, SU sidedraft carbs and .10ths off of 1/4 mi. times here. 2.The 2.5's were tough, mass produced, low powered utility vehicles, not a one-off handbuilt European sportscar with mechanical fuel injection & twin magnetos. 3. I don't have an exhaust gas analyzer either! You can tell by the smell when they ain't running well!
D. Team Rush Mod- Doesn't apply here either, but a good quality cap, rotor, plugs, and wires CAN be had. See #3- GOOD stuff, not c-store auto dept! My CDI (ignition) box is also Standard Motor Products' clone of the Ford "blue grommet" box.A note on plugs, here- 35 yrs of experience shows that NGK plugs are more reliable than about anything else, including the new plug 'o the week for $8-15 apiece. See above note.Sorry.
E. Cold Air Intakes- The intake your early XJ came with is as about as "cold air" as it gets- except for actual snorkels & scoops. Mounting a K&N cone filter underhood is NOT a cold air intake- it's a warm underhood air intake. The Masonite disc and taller filter I installed is in addition to the factory cold air intake for the summer.A 2 1/2 in. tall top I fabricated from the bottom of a 25 gal. plastic barrel goes on for winter because the factory lid won't fit over the tall air filter.You can't use a disc lid with the stock filter- it's 3/8" shorter than the clearance "hump" for the choke. Remember, this is about driveability and gas mileage, not high performance and the hot part 'o the week. If you want, put on a functional louver or scoop above the now open element air filter. I didn't, simply because I drive in NW Minnesota winters- nuff said. A later article will have drawings/pix of some other cold air intake ideas, with winter/water blockoff capability, etc.
F. Carter/Weber YFA Carbs- This will not fix soaked floats, cracked castings, worn out pivots, bushings, etc. YFA's can be made to function well, but keep this in mind,especially you younger guys & gals that grew up on fuel injection-anything carbureted will smell rich to you! This is also not about specific parts, jets, pump diaphragms,etc. YFA's are not high performance carbs, so jet #456 probably works as good as jet #457 or whatever their sizing system is. This is about running what you have!!! Mine has an acc pump bleed, maybe yours doesn't, etc. See note "C". It will run better no matter what! The HyGrade kit includes a needle&seat, but not a float. They are available separately, P/N FL24. If your float doesn't float in a small container of gas, it's soaked & time for a new one.
G. Some Parts Interchanges/Crossovers- Thanks to Doug & Dobbs at our local AutoValue for doing tedious dimensional (sizing) research. These are AutoValue (PartsMaster) numbers: AIR FILTERS: Stock #62054 Tall #62073. There is a WIX prefilter available for P/N 62073- WIX #24709, about$3! If you insist on spending the $60-100, the K&N air filter P/N's are E-1290 or E-1300. Their 11" XStream filter top P/N is 66-1101.The E-1290 is 0.13" taller- big deal.There are taller air filters available, but these fit under the hood. OIL FILTERS: Short #61042 Long #61522,SAE thread size 13/16"x16. BE WARNED! Yours might use a short #61040 oil filter like my "86 2.5 XJ, ISO thread size M18x1.5.The long version of it is #1-3980. NEXT WARNING! To use the long #61522 or #1-3980 oil filter, you'll have to grind 3/8" off the motor mount lip just to the right of the filter. Don't worry, it's not structural! Why the longer/taller filters? MORE FILTER AREA = more airflow, more oil filtration, more better!
F.My Most Godawful Infuriating Problems Encountered With XJ Wiring- Some of this lobotomy started when the '84's PCV solenoid wiring fell against the exh. manifold, burned off, shorted out, killed the engine in city traffic, and took a lot of other stuff out with it. After getting towed home, tracking it down, cutting it out, rewiring, & redoing with plain hose, the PCV solenoid was the first thing thrown. Didn't know the factory recall (replace with just hose)'til a few weeks ago.Very funny-thanks EPA. The '86 smoked a fusible link 2 yrs ago- RENIX, so no plug in diagnosis for this one, either. Days of tracing with the wiring diagrams and a VOM. It would start, then run/die at 15sec. to 5 min intervals. While leaning on the right fender, key on, engine off, I heard a 'sizzle/click'. The charcoal canister purge valve was partially shorting as it came on, killing power to the TBI it was in circuit with. Cut the wires to the purge valve, fired it up and it's ran ever since. Way to go AMC, lawyers, accountants, EPA, and anybody else that designs "cars by committee". Let engineers and designers build vehicles."What do you mean YOUR'E going to drive the car?" My favorite line from "I, Robot"
E. The Great Underhood Vacuum Hose Quagmire AKA The Sucking Spaghetti Monster From Toledo,etc.- Work carefully, fear not, and be just. MOST, BUT NOT ALL of the emissions vac lines are black rubber, 1/4" or larger. HVAC and 4x4 hoses are 1/8" poly, and mostly color coded, with short rubber connectors where needed.The P/A and emissions systems got their vac source from the carb, while 4X4 & HVAC get their vac source from a fitting directly on the intake manifold. These two systems are NOT interconnected, so it's hard to screw it up, unless you- 1. Inherited PO's mess, or 2. Try really, really hard to to mess it up. There are good sites showing complete vac maps out there, or you could use a factory manual to trace lines.You CAN permanently engage the front axle disconnect- use your own judgement about wear & MPG.My '86 has been permanently engaged for years, and has over 254K. Some XJ's & later Eagles didn't have the disco at all.Commercial or homemade cable operated front axle discos work, and so do aftermarket lockout hub conversions - $$$!
F. The XJ: "84 Series 78 (4dr/4wd) with 4" lift, 31x9.50x15 Cooper Discoverer STT's, P/S,P/B. No performance mods to engine or drivetrain. Used for work, hunting, fishing,
trips to the city, adventures. Mileage unknown due to odometer tampering, best guess is 200,000 +. No ABS, GPS, MP3,CHMSL, SRS, or DVD.However, it does have a first aid kit, fire extinguisher, 110v inverter, and compass. Paid $1300 for it at our local Chrysler dealer- with ATK rebuilt engine, new exhaust manifold, alternator, dis-
tributor, battery, brakes, clutch, and rodded(cleaned) radiator. Having the implied liability of being a factory dealer, plus the time ($) involved to do this, it didn't run or idle very well when purchased!!! Same dealer replaced my 86's cat con for free in '02. It was still under a valid factory recall.
G. In spite of the copyright below, which protects my intellectual property & authorship of this article, PLEASE COPY, HAND OUT, & USE THIS INFORMATION! Good Luck & Keep On Jeepin' !!!
MERRY CHRISTMAS!
Entire contents copyright Oct. 5, 2009 by Wilco40 AKA Mike Wickern / Blackdog Motorsports Ada,MN
This tech article was not written or approved by John Nutter, nor was he involved in any phase of the "HAL 9000 XJ Lobotomy"
As usual, do all of this at your own risk, I assume NO responsibility for you and/or your lawyer's stupidity and/or inability to follow directions!!!
1.THE NUTTER BYPASS: Do it exactly as his article says- it's essentially 3 wires on an XJ, plus a timing reset.Just unplug the MCU at the CDI box, and splice the distributor to the CDI harness. Don't just twist & tape wires- use terminals, then tape, then factory type split convolute looming. I call this version " PLUS" because of the carb mods on the YFA are roughly equivalent to the mixture needle disabling on a BBD. All hail John Nutter! The '84 started running better as soon as the bypass was
done, but the carb work & P/A removal is an essential part of this mod. Remember to reset the timing too, because now you can- without MCU interference.
2. THE HAL 9000 XJ LOBOTOMY: After HAL (the computer, MCU, CPU, CEC, or whatever you want to call it) is disconnected/disabled as per the Nutter bypass, the entire emissions quagmire will be non-functional (NF). This enables the removal of the PulseAir system and ALL of it's attendant hoses, valves, solenoids, wiring, etc. On the carb, the SoleVac idle control, WOT switch, and the mixture control solenoid are also eliminated.The EGR is in normal (no introduction of exhaust) mode, the catalytic converter has been gutted, and the O2 sensor has a Mv signal, but nothing to send it to. All wires, vac lines and solenoids/valves on the PCV and bowl vent were removed and all wiring harnesses and connectors stubbed and taped for later removal. My manifold heat and choke are still connected, as is TAC for heated intake air in winter. Operate the TAC from manifold vacuum. Plug all vacuum nipples not used! Exhaust manifold ports for the PulseAir were welded shut, and the cat con can be plugged or hammered/bent shut at it's P/A inlets, or removed entirely. If you want, or have to, install a new cat con ($$$), but not a used one- the monolith type catalyst element will more than likely be mostly plugged from years of overrich running. For more under hood room, and because it was NF, the cruise control actuator and vacuum cans were removed also. Redo the PCV with emission hose, not fuel line! (PCV vacuum will collapse fuel line).Fuel line is OK for the bowl vent, but make it long enough to vent gas fumes away from the exhaust manifold. Remove the carbon canister and all its hoses as well.The 4 hose temp/vac valve on the front of the exhaust manifold is NF, so remove the hoses. Knock sensor, anti-diesel relay & timer, EGR air cleaner temp, & power steering "idle up" sender are NF now also!! ALL this engine needs to run is a PCV hose and a vacuum advance hose to the distributor! Follow the Nutter Bypass by installing a new vac line from the distributor to ported vacuum on the carb- same vac nipple the factory hose was connected to, but don't reuse the factory pipe/hose/tee's, it's not getting vacuum anymore! Carefully remove all NF hoses, wire harnesses, connectors, etc. for salvage now, or tape/stub off and zip tie out of the way. Keep in mind, ALL these systems were tacked on AFTER the basic engine/carb/ignition were designed and running! See note "A".
3. THE CARB: Essentially, I've turned the feedback YFA into a YFA (YF w/automatic choke). Remove the mixture solenoid, WOT switch, SoleVac, & brackets, & tape off or remove the wiring harness. Curb idle will now be set by using a longer screw with the stock spring, it will contact the carb base like an old YF.I used the fast idle screw from another YFA. Fast idle will be set on the choke cam/counterweight. Choke setting and pulloff setting will need to be changed! Squeeze or widen the "V" in the pulloff linkage wire- that's what it's for. My mixture solenoid blockoff plate is a piece of 2mm thick aluminum using the stock gasket, with 2 spacers on the outside so I could use the stock screws.Don't use plastic unless you know it's fuel resistant! The interior carb passages for the mix solenoid are NF when the blockoff plate & bleed passage plug are installed- see next line, and fear not! With the top (air horn) of the carb removed,there is an angled bleed passage visible on the top rear wall of the float bowl for the mix control bleed- it's between the mounting bolt hole & the idle jet fuel inlet - I blocked this off with a piece of 6-32 screw wrapped in teflon tape and pushed in so it is below the mating surface to the air horn.Don't use silicone!!! Suitable diameter soft aluminum wire or epoxy may also work, but make sure the epoxy is fuel resistant & fully cured before reassembly! You have to block the bleed passage for this mod to work! I've also installed a $30 Mr.Gasket fuel pressure regulator set at 2 1/2 psi, and disposed of the inlet/outlet/return filter.Keep in mind the return filter was a "band-aid" to allow the use of the 6-8psi fuel pump! High fuel PSI=leaking needle & seat =overrich, crappy running! Plug the return line on the left inner fender, and use a inlet/outlet filter.My filter is clear so I can see when it's dirty.The plug over the idle mix needle was removed & needle set at 1 1/2 turns out, yours may vary slightly. I use a vac gage to set mixture.Higher vac = leaner mixture.Lean til it stumbles then back off til it runs smooth again. Install a new O-ring on the needle! I also cut a 11" disc of 3/16" Masonite as the top of a new taller filter (P/N below) for more intake airflow. See notes "E" and "G". Metering rod & float height were checked/adjusted also. Float height & drop are CRITICAL! The choke has been reset for winter use- drill out rivets, follow carb kit or shop manual instructions to get a baseline calibration & go from there. Don't re-rivet the choke spring housing-use screws or nut/bolt it-this makes it easier to fine tune/adjust. Choke pulloff is sourced to manifold vacuum to make sure the choke opens fully. It doesn't need to get any more technical than this. The '84 got a HyGrade carb kit by Standard Motor Products, P/N 1484 (Made in USA!) due to a hole in the acc pump diaphragm. If it needs a carb kit, and it probably does,do it now! Buy a GOOD one, not one from the auto dept. at the c-store!!! See notes "C" & "F".
4.THE RESULTS: Cold OR warm, 1 tap, 1 crank starts, pulls 18in.hg vacuum at idle, not 8-10in.hg as before.Revs to 4000+, not 2900. 950 rpm curb idle,1900 rpm fast idle. No black clouds or visible fuel spray in carb, clean plugs, smoother idle, improved driveability, more percieved power, no stumbling & hesitation, NO STINK! Mileage before:Town- 8 to 10 Hwy- 15 . Mileage after: Town-15+ Hwy-19+ (Highway MPG is an aggregate of 55mph state road, 65-70mph interstate, 55-60 intown interstate). All of this cost about $100 for wire, hose, plugs, air/fuel filters, fuel regulator, & carb kit, plus my time. I'm being conservative on the MPG figures, yours may be better, but certainly not worse.
5. RANDOM NOTES:
A. Why the HAL 9000 lobotomy reference? Just like in "2001: A Space Odyssey", the paranoiac, overcontrolling, (EPA/emissions) brain has been neutralized, leaving the very vital autonomous operating functions (fuel/air/spark) intact. No, my '84 is not named "Discovery", and I'm not Winston Smith.
B. Timing: Was set with a vacuum gage, I feel it's more accurate and indicative of engine performance.Advance is adjustable, but there are plenty of good websites that go into setting optimum advance in great detail.Make sure both vacuum & centrifugal advance are functional! Comments on vac timing are welcome, it works very well, and I've done it for decades on a multitude of engines.Any spark knock, set vacuum back 1in.hg. Dieseling isn't a problem with proper timing & fuel! For what it's worth, ignition timing is 18 degrees BTDC, total advance is 26 degrees BTDC, plug gap .035. It runs on Cenex 91 octane (10% ethanol) & 30wt(10 winter) oil quite well. See next note!
C.DON'T GET ANAL ABOUT THIS! 1.This is not about esoteric & oddball performance modifications- just reliable driveability. We're not talking recurving distributors, SU sidedraft carbs and .10ths off of 1/4 mi. times here. 2.The 2.5's were tough, mass produced, low powered utility vehicles, not a one-off handbuilt European sportscar with mechanical fuel injection & twin magnetos. 3. I don't have an exhaust gas analyzer either! You can tell by the smell when they ain't running well!
D. Team Rush Mod- Doesn't apply here either, but a good quality cap, rotor, plugs, and wires CAN be had. See #3- GOOD stuff, not c-store auto dept! My CDI (ignition) box is also Standard Motor Products' clone of the Ford "blue grommet" box.A note on plugs, here- 35 yrs of experience shows that NGK plugs are more reliable than about anything else, including the new plug 'o the week for $8-15 apiece. See above note.Sorry.
E. Cold Air Intakes- The intake your early XJ came with is as about as "cold air" as it gets- except for actual snorkels & scoops. Mounting a K&N cone filter underhood is NOT a cold air intake- it's a warm underhood air intake. The Masonite disc and taller filter I installed is in addition to the factory cold air intake for the summer.A 2 1/2 in. tall top I fabricated from the bottom of a 25 gal. plastic barrel goes on for winter because the factory lid won't fit over the tall air filter.You can't use a disc lid with the stock filter- it's 3/8" shorter than the clearance "hump" for the choke. Remember, this is about driveability and gas mileage, not high performance and the hot part 'o the week. If you want, put on a functional louver or scoop above the now open element air filter. I didn't, simply because I drive in NW Minnesota winters- nuff said. A later article will have drawings/pix of some other cold air intake ideas, with winter/water blockoff capability, etc.
F. Carter/Weber YFA Carbs- This will not fix soaked floats, cracked castings, worn out pivots, bushings, etc. YFA's can be made to function well, but keep this in mind,especially you younger guys & gals that grew up on fuel injection-anything carbureted will smell rich to you! This is also not about specific parts, jets, pump diaphragms,etc. YFA's are not high performance carbs, so jet #456 probably works as good as jet #457 or whatever their sizing system is. This is about running what you have!!! Mine has an acc pump bleed, maybe yours doesn't, etc. See note "C". It will run better no matter what! The HyGrade kit includes a needle&seat, but not a float. They are available separately, P/N FL24. If your float doesn't float in a small container of gas, it's soaked & time for a new one.
G. Some Parts Interchanges/Crossovers- Thanks to Doug & Dobbs at our local AutoValue for doing tedious dimensional (sizing) research. These are AutoValue (PartsMaster) numbers: AIR FILTERS: Stock #62054 Tall #62073. There is a WIX prefilter available for P/N 62073- WIX #24709, about$3! If you insist on spending the $60-100, the K&N air filter P/N's are E-1290 or E-1300. Their 11" XStream filter top P/N is 66-1101.The E-1290 is 0.13" taller- big deal.There are taller air filters available, but these fit under the hood. OIL FILTERS: Short #61042 Long #61522,SAE thread size 13/16"x16. BE WARNED! Yours might use a short #61040 oil filter like my "86 2.5 XJ, ISO thread size M18x1.5.The long version of it is #1-3980. NEXT WARNING! To use the long #61522 or #1-3980 oil filter, you'll have to grind 3/8" off the motor mount lip just to the right of the filter. Don't worry, it's not structural! Why the longer/taller filters? MORE FILTER AREA = more airflow, more oil filtration, more better!
F.My Most Godawful Infuriating Problems Encountered With XJ Wiring- Some of this lobotomy started when the '84's PCV solenoid wiring fell against the exh. manifold, burned off, shorted out, killed the engine in city traffic, and took a lot of other stuff out with it. After getting towed home, tracking it down, cutting it out, rewiring, & redoing with plain hose, the PCV solenoid was the first thing thrown. Didn't know the factory recall (replace with just hose)'til a few weeks ago.Very funny-thanks EPA. The '86 smoked a fusible link 2 yrs ago- RENIX, so no plug in diagnosis for this one, either. Days of tracing with the wiring diagrams and a VOM. It would start, then run/die at 15sec. to 5 min intervals. While leaning on the right fender, key on, engine off, I heard a 'sizzle/click'. The charcoal canister purge valve was partially shorting as it came on, killing power to the TBI it was in circuit with. Cut the wires to the purge valve, fired it up and it's ran ever since. Way to go AMC, lawyers, accountants, EPA, and anybody else that designs "cars by committee". Let engineers and designers build vehicles."What do you mean YOUR'E going to drive the car?" My favorite line from "I, Robot"
E. The Great Underhood Vacuum Hose Quagmire AKA The Sucking Spaghetti Monster From Toledo,etc.- Work carefully, fear not, and be just. MOST, BUT NOT ALL of the emissions vac lines are black rubber, 1/4" or larger. HVAC and 4x4 hoses are 1/8" poly, and mostly color coded, with short rubber connectors where needed.The P/A and emissions systems got their vac source from the carb, while 4X4 & HVAC get their vac source from a fitting directly on the intake manifold. These two systems are NOT interconnected, so it's hard to screw it up, unless you- 1. Inherited PO's mess, or 2. Try really, really hard to to mess it up. There are good sites showing complete vac maps out there, or you could use a factory manual to trace lines.You CAN permanently engage the front axle disconnect- use your own judgement about wear & MPG.My '86 has been permanently engaged for years, and has over 254K. Some XJ's & later Eagles didn't have the disco at all.Commercial or homemade cable operated front axle discos work, and so do aftermarket lockout hub conversions - $$$!
F. The XJ: "84 Series 78 (4dr/4wd) with 4" lift, 31x9.50x15 Cooper Discoverer STT's, P/S,P/B. No performance mods to engine or drivetrain. Used for work, hunting, fishing,
trips to the city, adventures. Mileage unknown due to odometer tampering, best guess is 200,000 +. No ABS, GPS, MP3,CHMSL, SRS, or DVD.However, it does have a first aid kit, fire extinguisher, 110v inverter, and compass. Paid $1300 for it at our local Chrysler dealer- with ATK rebuilt engine, new exhaust manifold, alternator, dis-
tributor, battery, brakes, clutch, and rodded(cleaned) radiator. Having the implied liability of being a factory dealer, plus the time ($) involved to do this, it didn't run or idle very well when purchased!!! Same dealer replaced my 86's cat con for free in '02. It was still under a valid factory recall.
G. In spite of the copyright below, which protects my intellectual property & authorship of this article, PLEASE COPY, HAND OUT, & USE THIS INFORMATION! Good Luck & Keep On Jeepin' !!!
MERRY CHRISTMAS!
Entire contents copyright Oct. 5, 2009 by Wilco40 AKA Mike Wickern / Blackdog Motorsports Ada,MN
This tech article was not written or approved by John Nutter, nor was he involved in any phase of the "HAL 9000 XJ Lobotomy"
As usual, do all of this at your own risk, I assume NO responsibility for you and/or your lawyer's stupidity and/or inability to follow directions!!!
