Once again, same problem, different solution.

[BlackMount]

So, same problem. Cuts + Misses at 2500-3000 rpms, runs perfectly for the first 5 mins after start up and hauls ass, till it starts to warm up then it just cuts and misses. READ BOLD UNDERLINED POINTS CAREFULLY AND ANSWER THOSE SPECIFIC POINTS part of my problem diagnosing this is people not reading my post thoroughly. No offense.

Things I've tried.

New Spark Plugs
Spark Plug Wires
New MAF
New ECU
Cleaning Injectors
Re-Timed and Dead on.
Different Coil Pack
Different CAS

Other things I've Tried.
Unplug MAF, it just get's worse!

Pulled off my Waste Gate actuator arm, so I couldn't Fill up with boost (and that worked properly) in theory of having fuel cut due to large boost leak I found at my Intake Manifold Flange... Results!

No Boost = Cuts + Misses @ Lower RPMS like 2000 flat So having Boost makes me cut less.... ????

I found out if I'm very light on the throttle, like very tiny amount, it will rev all the way up in Nuetral to 5,000 RPMS.

Some one Explain this. I poof black smoke out of my Exhaust which means I'm running rich...I'm gonna try changing out my Injectors, but 450cc injectors aren't easy to come by and money is Tight....I was thinking about running Open Waste Gate (No Boost At All) and putting some Injectors from a 2.4L 4G64, or N\T 4g63 just because they are plentiful at the junkyards, and just seeing if maybe I have a stuck injector. I would only be using those injectors for diagnosing, and not run with them.

are the Turbo Fuel Pressure Regulators and N\T rated differently? I want to try replacing that also!


HELP

 

[chaggard27]

Do you have any white smoke once the engine is running rough around 2500 rpm? To me it sounds like a blown head gasket and that you are getting coolant in the cylinders which is flooding that cylinder therefore making it run on 3 or less. Do you have any engine codes?

 

[BlackMount]

Do you have any white smoke once the engine is running rough around 2500 rpm? To me it sounds like a blown head gasket and that you are getting coolant in the cylinders which is flooding that cylinder therefore making it run on 3 or less. Do you have any engine codes?

No white smoke, Only Black like Turbo Diesel Truck black, No burning Water\Coolant Either, No Over Heating. It runs on all 4 cylinders fine, and when it starts to cut\miss it sounds like Launch Control...


Another Point Sometimes my Tachometer will jump 100 not 1000, just 100 and it will bounce a little randomly usually @ idle or after down shifting and letting the motor wind down.



Little Details...

Doesn't smoke White\Blue or Burn Oil
Idle's Pretty smooth, but never cold Idles.
Doesn't Leak Oil
Proper Oil Pressure
Proper Running Temperature
No CEL

 

[stefanOst]

What kind of fuel pump are you running in the car? If you have a 255lph, you may be overrunning the stock FPR, and should consider switching to an aftermarket AFPR.

Do you have a wideband o2? If you do, you can tell what AFR you are running at idle and under throttle?

 

[2gmummy]

Black smoke is fuel, kind of sounds like fuel cut, is your fpr working?

 

[BlackMount]

What kind of fuel pump are you running in the car? If you have a 255lph, you may be overrunning the stock FPR, and should consider switching to an aftermarket AFPR.

Do you have a wideband o2? If you do, you can tell what AFR you are running at idle and under throttle?

Yes, I'm running 255 lph, and I'm aware that it could be over running my FPR. But I cant afford a stock Pump, no one sells them for decent price, and I'm tired of spending money on fixing it, I want to try replacing my FPR first but no one has answered my question about the N\T FPR, and the Turbo FPR


and no, Cant afford Wideband, or anything....The car USE to run fine with the 255 Fuel Pump, so I don't think the fuel pump itself is the problem, I think it is FPR related but my question is still unanswered. (

Im amazed no one has had this problem on this site and or fixed it.)

 

[chaggard27]

No cel tells me that is would be something mechanical and not with a sensor. Have you done a compression test? Also possibly check your injectors. Unplug the fuel pump and take out injectors. Then hold injector in your hand while plugged in and have someone crank the engine. If you feel the injector vibrating or moving inside you know it is working. Do this with all injectors to see if they are all working however, I doubt it would be an injector since you have no CEL. have you checked your fuel filter?

 

[BlackMount]

No cel tells me that is would be something mechanical and not with a sensor. Have you done a compression test? Also possibly check your injectors. Unplug the fuel pump and take out injectors. Then hold injector in your hand while plugged in and have someone crank the engine. If you feel the injector vibrating or moving inside you know it is working. Do this with all injectors to see if they are all working however, I doubt it would be an injector since you have no CEL. have you checked your fuel filter?

The problem is too much fuel...not lack of fuel....If my fuel filter was dirty\clogged\or ristricting I would be running lean not rich....Common sense no offense.

Going to get some injectors maybe tomorrow.

 

[stefanOst]

The problem is too much fuel...not lack of fuel....If my fuel filter was dirty\clogged\or ristricting I would be running lean not rich....Common sense no offense.

Going to get some injectors maybe tomorrow.

Well, before changing injectors I would definitely suggest to take a look at the FPR. I've always understood that a 255 required an AFPR, but some now are saying that a stock FPR will be able to handle to extra flow, provided it is in good shape, essentially a new one. One of the Wisemen is really adamant about this. Either way, before changing injectors and adding more variables to the problem, look at the most obvious problem, which I think is the FPR.

 

[BlackMount]

Well, before changing injectors I would definitely suggest to take a look at the FPR. I've always understood that a 255 required an AFPR, but some now are saying that a stock FPR will be able to handle to extra flow, provided it is in good shape, essentially a new one. One of the Wisemen is really adamant about this. Either way, before changing injectors and adding more variables to the problem, look at the most obvious problem, which I think is the FPR.

That's what I plan on doing, is a 1g N\T FPR same as a 1G Turbo FPR?? I've asked over and over again and it keeps getting ignored!!


Don't make me start another thread just for that one question

 

[stefanOst]

That's what I plan on doing, is a 1g N\T FPR same as a 1G Turbo FPR?? I've asked over and over again and it keeps getting ignored!!


Don't make me start another thread just for that one question

I would have to assume that they are not the same, the 1G turbo runs at 37psi base fuel pressure, lower then the 1G N/T, which I believe is somewhere in the 40s. I could be wrong about that though. Either way, however, even if the regulator is the same, from what 95blackGsTurbo has been discussing, stock FPRs can manage the pressure if they are fairly new. If you have an old 1G N/T FPR, it could be worn out too and not solve the problem.

Check this thread for 95blackGsTurbo on FPRs.
http://www.dsmtuners.com/forums/newbie-forum/368030-fuel-presure-regulater.html

 

[chaggard27]

I have a stock 1g turbo fpr on my 2g with a 255 high output pump and it runs fine for me. Of course it ran rich but it never had an idle or stutter problem. Have you done a boost leak test as well?

 

[ramsack]

turbo manual: 36.3 psi
turbo automatic: 42.7 psi
non-turbo: 47 psi

 

[350war]

Correct me if I am wrong but arent those pressures at idle? The way I understand it the N/T fpr runs higher pressure only til boost.

 

[ramsack]

those are base pressures meaning with the car running and the vac line unplugged. any of those regulators should raise pressure with boost, but i have no idea if the n/t one is 1:1.

 

[350war]

With the 255 pump you probably still over run a N/T fpr.

 

[black_gst]

an NT FPR will not work

 

[black_gst]

they are not the same

 

[black_gst]

do you have a safc?

 

[gstbobby]

Just a thought, the catalytic converter could be stopped up.

 

[BlackMount]

Had some interesting stuff happen while diagnosing....

Cleaned my MAF, in hopes it might solve my problem or make it better, and it did nothing...so while messing with stuff, I put my hand over the hunny comb on the MAF, and gave the car a little Rev, and it reved high with no problem, Gave the car a slightly bigger rev, and it banged the rev Limiter and I went def when my BOV went off... so i went hmmm....and slapped a piece of tape over my MAF leaving about 3\4 inch on both sides for air flow, and got in the driver's seat and took off, it bogs a little if your under (2k) so in order for a smooth take off, you have to rev it up to about 2200, and let the clutch out a little bit slowly...so driving driving, got on a open road, in 2nd gear, 1\2 throttle easing my way into WOT....2k...3k..4k..5k...6k..7k shift to 3rd. @ 10 psi, and it hauled ass and didn't cut at all.... didn't notice any black smoke either.

(See Picture)

I know it's a lot to read but please read all of it, and then if you can explain why this made my car run so much better...would it be bad to run my car like this for a week or so?

 

[ramsack]

it would seem to me there's a problem with your maf then.

 

[2gmummy]

That is "IF" he has one haha! but that could very well be the problem, worth a look imo

A cat that is posts popped up at the same time..

Glad you got it fixed but i think there might be an underlining problem..putting tape on your maf and fixing it seems fishy to me

 

[BlackMount]

it would seem to me there's a problem with your maf then.

I have 2 MAFs, 1 with honey comb, and 1 with out, Both work normally, The one with the honeycomb makes my car run better (because its more restrictive?) so I think the problem is somewhere else.

That is "IF" he has one haha! but that could very well be the problem, worth a look imo

A cat that is posts popped up at the same time..

Glad you got it fixed but i think there might be an underlining problem..putting tape on your maf and fixing it seems fishy to me

Cat is gutted (and yet I still passed emissions ),

and yeah the tape makes me feel uncomfortable too...that's why I'm asking....The car runs much better tho. for once I can actually do the speed limit on the interstate with out going down hill or dealing with severe jerking. (70mph)

 

[ramsack]

the honeycomb is there to provide laminar flow of air. removing the honeycomb destroys that and will throw off readings.