List all of your "heat soak", "hot soak" fixes

[joe_peters]

Just joined this forum today to chime in on this thread.
Let me first introduce myself.
420BlackXJ means just what it says. All 4 hub to flare measurements = 20 inches on my black Cherokee. What, you were thinking something else:greensmok


On topic, I have had this issue with my XJ since I bought it in Oct. 2000
It is an 01. Dealer said the "fix" is in. BS. The little insulator between the intake man. and the inj. rail is insufficient. Right now, to get around this problem, I have been opening the hood every time I run into the liq store for a sixer, and waiting 10 mins or so before restarting. This works every time if I wait long enough. This is the only forum I have visited where many wheelers are familiar with this issue. I have been living with it for a long time now, but it is interesting to see some of the fix suggestions out there. A permanent fix would be nice, might have to try a suggestion (or more) to see what fixes it for good.

http://www.at-fairfax.com/P1786-ELK-960.htm

Just Do It! (with apologies to Nike).

 

[bigdaddyjlove]

Emissions control devices on vehicles are a FEDERAL requirement, not state - only CA has more strict emissions regulations, which is why most vehicles are listed w/ "California Emissions Package" or "Federal Emissions Package" - just because the state you live in doesn't have emissions testing doesn't mean it is legal to remove your cat. It won't benefit you in ANY way to remove the cat.

.

Normally, I would agree with you 100%, My '88 off road toy passed emissions with flying colors last week.

BUT. In this case, the poorly designed emissions equipment causes a real driveability problem. Coupled with the fact that the vehicle has a regular catalyst further down the exhaust, and that these two pre cats exist only to satisfy California's cold start regs, I personally se nothing morally objectional in removing them.

 

[xjtrailrider]

Back on Topic, XJTrailrider. I too am surprised you're having this issue. I assume it's the rough idle/run after a hot start that clears up after a few minutes. You said this happened *AFTER* the FI swap. How do you know it was #3?

I'm not sure that it is #3 on my 90, I didn't dig that far into it. I wrapped all of the injectors with fiberglass batten and wired both E-fans to a thermostat that is right off the battery, this allows the E-fans to run even after shutdown to cool the engine bay. I also removed the splash guard under the engine to allow more cool air under the hood (yes i actually still have the original splash guard under it). I have the issue managed now as it only runs rough for about 5 seconds and smooths out and runs great with no issues. I'm getting killer mileage with ALL emissions devices connected/installed.

As for my co-workers 2 XJ's, I would really like to resolve the issue that they are having. Removing the cats is not going to happen, I would never suggest it and its just not a wise thing to do.

From what I am gathering the heat shields are not working and the E-fan timer is the most reliable fix?

Lets keep it on topic, anybody else have any good fixes for this issue that I can add to a very short list?

 

[BOBFBT]

befor you get carried away checked the voltage at that injector when the miss is active mine did the same thing .turned out to be the ECU

 

[m42duster]

I bet you could wire in a rotary dial timer switch (the kind you see on bath fans, hot tubs, etc.) I'm not sure what they are called, but they are spring operated. You just twist the knob and it counts down. I know they make them for high amp 12 volt systems. I thought someone here might know.

Anyhow, wire the thing in the cab, shut off engine, set dial to proper time and let the fan cool everythin down before it shuts off. probably get these things for small change.

I am looking and will report back with findings.

 

[joe_peters]

Went back and re-read the original post--your pards with the 00 and 01 most likely have heat soak.

You most likely do not.

Contributing factors to heat soak:

1. Elimination of the fuel return line from the fuel rail--97.

2. Redesign of the manifolds to regain HP lost to new emissions requirements--99.

3. Addition of the pre-CATS on the 50 state emissions vehicles.

At least that is how I see it in my most humble of opinions.

None of the above applies to any Renix. Start unwrapping the injector harness and look for a bad connection around the back of the head/firewall area.

 

[xjtrailrider]

Went back and re-read the original post--your pards with the 00 and 01 most likely have heat soak.

You most likely do not.

Contributing factors to heat soak:

1. Elimination of the fuel return line from the fuel rail--97.

2. Redesign of the manifolds to regain HP lost to new emissions requirements--99.

3. Addition of the pre-CATS on the 50 state emissions vehicles.

At least that is how I see it in my most humble of opinions.

None of the above applies to any Renix. Start unwrapping the injector harness and look for a bad connection around the back of the head/firewall area.

But it runs fine in all other conditions with the exception of the first 20-30 minutes after a hot shut down?

It only started doing the heat soak issue after I installed the second E-fan and the Ford orangish-yellow tops(yes I did both mods at the same time) I installed the second E-fan to fight a "running too cool" condition with my closed system/freshly rebuilt 4.0/3 core all brass radiator. It always ran too cool with the clutch fan and rarely made it past 150-160 with occasional spikes to 180 then back down, it was killing my mileage. The E-fans are on a thermostatic controller and allows me to keep the engine warmer at a constant 180. I have gained 100 miles per tank full(in town) with the warmer running engine and Ford injectors. Getting mid 20's highway on 4.10 gearing and 30's

 

[garr]

Experience talking here, I wrestled with the heat soak problem for 2 years before I installed the timer.
Do not bother wrapping the injectors or fuel manifold, just go straight to the "E" Fan timer; it is the only thing that works.

PS: After I removed the insulation from the injectors & fuel manifold I only have to run the "E" fan 2.5 minutes to prevent the problem, With the insulation in place I had to run it 3.5 minutes.

I wonder if Hood Vents will lessen the required "E" fan run time even more ?

 

[joe_peters]

Where are you measuring the constant 180 at?

My 90 4.0 runs at a constant 205 indicated on the IP gauge. OEM single-core rad, no aux fan, ZJ fan clutch, Stant SuperStat Premium 195 thermostat, and ZERO "heat soak" symptoms.

If you had "heat soak" I would expect to be able to find some source of high temps, but you say 180 degrees and that is low. So, again where are you getting that reading?

 

[xjtrailrider]

Experience talking here, I wrestled with the heat soak problem for 2 years before I installed the timer.
Do not bother wrapping the injectors or fuel manifold, just go straight to the "E" Fan timer; it is the only thing that works.

PS: After I removed the insulation from the injectors & fuel manifold I only have to run the "E" fan 2.5 minutes to prevent the problem, With the insulation in place I had to run it 3.5 minutes.

I wonder if Hood Vents will lessen the required "E" fan run time even more ?

Hood vents are out of the question in my application as well as my co-workers but I could see where they would help.

 

[xjtrailrider]

Where are you measuring the constant 180 at?

My 90 4.0 runs at a constant 205 indicated on the IP gauge. OEM single-core rad, no aux fan, ZJ fan clutch, Stant SuperStat Premium 195 thermostat, and ZERO "heat soak" symptoms.

If you had "heat soak" I would expect to be able to find some source of high temps, but you say 180 degrees and that is low. So, again where are you getting that reading?

Infra-red at the hose inlet on the radiator, that is where I have the thermostat probe for the E-fans. My dash temp gauge is close, about 5 degrees higher

 

[garr]

Infra-red at the hose inlet on the radiator, that is where I have the thermostat probe for the E-fans. My dash temp gauge is close, about 5 degrees higher

I don't think the temp at the Radiator has anything to do with the heat soak problem.
It has more to do with the high under hood temps caused by the dual cats on the later models + that dam ethanol the Socialist Pricks in DC require be added to the fuel!

 

[joe_peters]

Infra-red at the hose inlet on the radiator, that is where I have the thermostat probe for the E-fans. My dash temp gauge is close, about 5 degrees higher

Yeah, that makes even less sense to me. My sensor in the back of the head is reading 205, and your sensor in the radiator input says 180, and there is nothing between the back of the head and the radiator input to reduce temps. Too weird. Maybe 5-90 and some of the others will give their input.

Just for grins and giggles, could you measure the temps on your pards XJs after putting them into a heat soak condition, just to compare with measurements on yours?

 

[89xj]

maybe one or several of the injectors are leaking/staying open or you have a bad o-ring seal or tear. its very easy to damage an o-ring on the installion of injectors. it just doesnt seem to be heat soak. you also said that it lasts for about 20-30 minutes after shut down, which leads me to believe an injector o-ring may not be seated proporly and when it expands/contracts it solves/creates the problem. it just doesnt seem like the heat soak issue associated with the 2000-01 xjs.

FWIW, the longer my 89 renix runs at 210 degrees or the hotter it is outside, the better fuel economy it gets.

 

[jimmy21669]

This is why I drive a 91.

 

[89xj]

This is why I drive a 91.

as oppossed to driving a renix(87-90) or a 2000-01?

 

[veedubshafer]

Try bags of ice.....I love my hollow cat! Bwahahahahahahahaha!

Only idiots and mouthbreathers think it's ok to drive with no cat or a hollowed cat. Anyone care to guess which one I am? :dunce:

 

[89xj]

I love my hollow cat! Bwahahahahahahahaha!

becuase it matches your hollow head?

 

[kastein]

Went back and re-read the original post--your pards with the 00 and 01 most likely have heat soak.

You most likely do not.

Contributing factors to heat soak:

1. Elimination of the fuel return line from the fuel rail--97.

2. Redesign of the manifolds to regain HP lost to new emissions requirements--99.

3. Addition of the pre-CATS on the 50 state emissions vehicles.

At least that is how I see it in my most humble of opinions.

None of the above applies to any Renix. Start unwrapping the injector harness and look for a bad connection around the back of the head/firewall area.

Minor correction - fuel return line was eliminated for 96. Why do I know? I have one of those amazing machines... add this to the list of "red headed stepchild" features on the 96.

This is why I drive a 91.

The OP of this thread drives a 90 RENIX, which has most of us fairly puzzled as to why he's seeing heat soak.

Try bags of ice.....I love my hollow cat! Bwahahahahahahahaha!

becuase it matches your hollow head?

:roflmao:

 

[veedubshafer]

I'm an idiot and a mouth breather so theres no guessing there LOL......and theres plenty of cars driving around here that were made before they came out with converters. So whats the difference? I'm not going to go and buy a new converter everytime I go wheelin' and mangle it on a rock! If you wanna foot the bill I will but until then......NO! Now, my street vehicles all have converters.