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Strokers and Emissions testing

wascobi

NAXJA Forum User
has anyone had any trouble passing emmissions tests after building a 4.0 to 4.6 stroker? or done any anylizing of exhaust gasses before and after? I would hate to build it and not be able to pass!
 
Emissions is rarely a problem. I didn't pass the CO portion but I rigged a MAP sensor adjuster and things are great. I can help you if you have any problems. I went with the 24# Ford high performance injectors and they were just a bit too big for this altitude. The adjuster took care of everything.
 
More than likely you can. What altitude are you?
 
I have Ford 24lb injectors and stock 39psi regulator on my HO-based 4.6 stroker and the MAP adjuster set at 5.35v. At that voltage, my A/F ratios are stoichiometric at idle and light throttle cruise and I'm at an elevation of 2100ft.
_________________________________
1992 XJ Laredo 4-dr - 4.6L I6 HO Stroker - 177k miles - AX15, NP231, D35c, D30
Estimated 261hp/322lbft, 1/[email protected], 0-60=5.9
Websites - Jeep 4.0 Performance, 4.6L Stroker Build-Up, Dino's Jeep Tricks
 
4.6 stroker in Denver Metro area running Ford 24 lb injectors -- passed with flying colors -- WAAYY below the required standards.
 
One thing's clear enough; the default injectors for the vast majority of 4.6 strokers will be Ford 24lb'ers. Some might have perfect A/F ratios without needing further adjustment while others will need slight tweaking with a MAP adjuster.
Altitude shouldn't make any difference because the PCM automatically compensates for the reduced MAP voltage that you get at higher altitude (lower manifold pressure) by reducing the injector duty cycle.
 
is it odd then that I'm running 26 lb/hr injectors from Accel, and still get quite a knocking racket when pulling uphill, or even on flatland at half throttle or more? I drove to the mountains over the weekend and the engine knocked almost constantly all the way up- also got a bit warmer than it has up till now (240-ish)- lean condition, perhaps? octane doesn't seem to matter- i've tried 87, 89, and 91. 91 seems to knock a little less than lower grades of gasoline. I am also running the Mopar performance computer.

I'm going to try the adjustable MAP route, but is there anything else I should try looking at as well? bad knock sensor perhaps? quit screwing around and get 30 lb/hr injectors? :D
 
wascobi said:
has anyone had any trouble passing emmissions tests after building a 4.0 to 4.6 stroker? or done any anylizing of exhaust gasses before and after? I would hate to build it and not be able to pass!
Since when do they do mandatory emissions testing in BC? Or anywhere in Canada for that matter? As far as i know, its entirely voluntary here. As long as your vehicle is legally registered for street in BC, you can take it anywhere in North America, whether they have emissions restrictions or not. My "ICBC accredited inspection agency" (ie, Canadian Tire) did not blink an eye to my 82 Camaro, blower, nitrous and all. As long as you can get an accredited mechanic to pass you in an inspection, you have nothing to worry about. They only check to make sure that everything that is installed is working correctly, they don't check to see if its been modified. And, why would you need an inspection anyway unless it has a wrecker title or you are bringing it in from out of province? If it already registered, you don't need an inspection. If you have to get an inspection before registering, just go get it passed before you build the stroker and then build away, they will never know the difference one way or the other.
Don't worry about the emissions test on a stroker or supercharger, they just don't do it here.
Buck :canada:
 
cbremer said:
is it odd then that I'm running 26 lb/hr injectors from Accel, and still get quite a knocking racket when pulling uphill, or even on flatland at half throttle or more? I drove to the mountains over the weekend and the engine knocked almost constantly all the way up- also got a bit warmer than it has up till now (240-ish)- lean condition, perhaps? octane doesn't seem to matter- i've tried 87, 89, and 91. 91 seems to knock a little less than lower grades of gasoline. I am also running the Mopar performance computer.

I'm going to try the adjustable MAP route, but is there anything else I should try looking at as well? bad knock sensor perhaps? quit screwing around and get 30 lb/hr injectors? :D


With the Mopar Performance ECU I am guessing Renix? The 240 dF indicates a lean condition, but it can also mean other problems (overly agressive timing).

Distributor indexing is a first recommendation, knock sensor replacement, and then MAP adjustment, followed by an adjustable CPS.

The 26#/hr injectors should be more than adequate for flow, a rich condition (30#/hr injectors) will hide the true problem. The ECU will close loop adjust for O2 on idle and cruise, and default to open loop on WOT. If the detonation goes away at WOT the injectors are probably sized OK, but the other issues need tuning. If the O2 sensor fails it will not control properly in closed loop (part throttle & cruise).
 
cbremer said:
is it odd then that I'm running 26 lb/hr injectors from Accel, and still get quite a knocking racket when pulling uphill, or even on flatland at half throttle or more? I drove to the mountains over the weekend and the engine knocked almost constantly all the way up- also got a bit warmer than it has up till now (240-ish)- lean condition, perhaps? octane doesn't seem to matter- i've tried 87, 89, and 91. 91 seems to knock a little less than lower grades of gasoline. I am also running the Mopar performance computer.

I'm going to try the adjustable MAP route, but is there anything else I should try looking at as well? bad knock sensor perhaps? quit screwing around and get 30 lb/hr injectors? :D

The Accel 26lb injectors are rated to flow 25.8lb/[email protected]. At 39psi (stock '87-'95 4.0 fuel pressure), they flow 24.3lb/hr so they're only marginally bigger than the Ford 24lb'ers.
Since your stroker's a Renix version, I think it's unlikely to be running lean with those injectors. There's probably other reasons for the knocking. What's the CR of your engine? Which camshaft did you use? A high CR combined with a short duration cam is a sure recipe for detonation problems. Your MP computer may also be advancing the timing too much and the knock sensor can't pull enough timing back to prevent pinging.
Is your cooling system up to scratch?
Is your intake inhaling cool air or hot underhood air?
 
cbremer said:
is it odd then that I'm running 26 lb/hr injectors from Accel, and still get quite a knocking racket when pulling uphill, or even on flatland at half throttle or more? I drove to the mountains over the weekend and the engine knocked almost constantly all the way up- also got a bit warmer than it has up till now (240-ish)- lean condition, perhaps? octane doesn't seem to matter- i've tried 87, 89, and 91. 91 seems to knock a little less than lower grades of gasoline. I am also running the Mopar performance computer.

I'm going to try the adjustable MAP route, but is there anything else I should try looking at as well? bad knock sensor perhaps? quit screwing around and get 30 lb/hr injectors? :D

I'm running 24lb injectors and was running way too rich so now I have the MAP adjuster down to 4.1v and I don't have any pinging? I think it could be because I swapped an HO fuel rail and FPR on.
 
buck
you islander! here on the lower mainland we have the aircare program. no pass, no insurance. I just hate the thought of having to buy another set of injectors when these have only 8,000 km's on them, but if I have to it will be from 5-O motorsports again.
 
CW said:
I'm running 24lb injectors and was running way too rich so now I have the MAP adjuster down to 4.1v and I don't have any pinging? I think it could be because I swapped an HO fuel rail and FPR on.

Wow, your MAP voltage is way lower than mine. I'm puzzled at how your stroker can need so much less fuel than mine. Less airflow-enhancing mods perhaps?
 
I have no explination for it. I have a homebrew fipk, HO intake, poted head.... I am completely stumped. But it runs awsome and my A/F ratio guage reads stoich. :dunno:
 
wascobi said:
buck
you islander! here on the lower mainland we have the aircare program. no pass, no insurance. I just hate the thought of having to buy another set of injectors when these have only 8,000 km's on them, but if I have to it will be from 5-O motorsports again.
Dammit! I knew it was coming, but i did not know it was here already! What the hell am i going to do with my 81 civic? From the looks of their website though, it seems like you only need to do it if you are relicensing, not just reinsuring. (transferring title, or registering by you for the first time) Is that the case with your rig? Also, it seems like they check your emissions, but compare them to all other vehicles that weigh the same with same motor displacement. They don't appear to compare them to other vehicles of the same make and model. Perhaps you might have a little leeway there? I feel for you brother. It won't be long before all the long-hairs on the island move that direction too.
Sadly,
Buck :canada:
 
Steve88XJ said:
4.6L stroker, 30lb/hr injectors, comp xtreme4x4 camshaft (not smog legal)... passed CALIFORNIA smog :D
that's reassuring :D

Dino, I used the Crane 753901 camshaft, replaced the cooling system (GDI rad, Flowkooler pump, Mopar thermostat & housing), and the have stock intake w/ bored throttle body. I calculated somewhere between 9.4-9.5:1 CR (closer to 9.4)

Ed, you're right- Renix computer. I initially had the distributor retarded 1 tooth and fixed that after discovering how poorly it ran at first :) I think advancing it another tooth will really mess things up. As it is now, WOT probably results in the worst knocking, at least until it gets past 2500 RPM or so, or until i let up off the gas pedal. Any load, uphill, or if it happens to lug in any gear gets me a nice can o' rocks sound.

I think the first step will be reinstalling the stock computer to see of that solves the problem. Eliminate the obvious first. I recall that the performance computer requires premium gas, even with the stock motor/CR. Increased CR + agressive timing advance = pinging, correct? :D
 
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