I have a 94 Formula, the fuel pump had taken a **** on me and was making it pop and sputter really bad if I gave it gas during load and had me stuck in open loop. Mostly from a stand still taking off.
I replaced it with a Walboro 255lph and hotwire kit. Car runs way better, goes into closed loop now, but I'm still getting a pop and stutter, if I drop the clutch from any rpm and if I get on it hard while at a really slow roll. When I bought the car with no mods at all I could have the rpms at 2 gran and drop the clutch, the tires would chirp and I would take off. I could turn a corner in 1st, bring it do 2nd and give it a some gas and spin around the corner, throttle response was amazing, can't do anything like that right now. Car just bogs for a second or two before it gets going.
My fuel psi is right at 39 at idle?? I know its off. If I take the vacuum line off the regulator it jumps to about 46-47. I'm trying to find a friend with a fuel pressure tester to see how accurate mine is as I have dropped it a couple times.
I do have an exhaust leak where my Y-pipe meets my old rusted cat-back and couple small ones where the Y-pipe is clamped to headers. They're after both the o2s though and I'm just about to buy a stainless Magnaflow cat-back and Y-pipe from a member here. So the leaks will be fixed soon.
With the fuel pump going out the last 4 plugs were fouled and the front 4 were looking fine. I have not replaced any plugs yet, but that will be the next thing on my list.
I just tried to do a brake stand also and it just dies or pops and sputters so I let off. Does not do this higher in the rpms at all. Only low rpms at heavy load.
I do have datamaster but I'm just getting to figuring it out.

Could it be that after the mods I have done I really need a tune? (Mods in sig) I am getting a SES light after a couple minutes of the car on and the codes are EGR, skip shift, and EAS elecrical fault.

What can I do to figure out why this is happening? I hope that the fuel pump I installed (correctly) is up to par, and by all means the 255 should be.
I know I'm missing things here and I really would like some people to chime in and also let me know what all I can check. I would like anyone who has even the slightest thought on what to do and where else to go check to just pop in and let me know what I could try. Thanks a million in advance!

 

it might because of the lts

 

I was thinking this as well.
Anybody else have an opinion? I really appreciate any and all the help!

 

I had a very similar problem on an old land cruiser.. Turned out to be a couple of the injectors were dunzo. Popped some new ones in and problems went away.. However the design was much different so this may or may not apply.

 

I did check to see if my injectors are leaking couple times throughout the last couple months. No leak there. How can I find out if my injectors are workin hard or hardly workin?

 

Well I figured out my problem. Turns out my #2 and #8 cylinders aren't firing... I checked #2 to see if it has spark, they have all new plugs in them so I just pulled the wire off it and put in an old plug and she sparks. I also switched #2 + #4 injectors around and #6 + #8 around and it is still the #2 and #8 that aren't firing... The primaries are a bit hot and evaporate a little water but I can touch them whereas the others are wayyy too hot and water instantly sizzles and evaporates on them. I feel retarded I didn't think 'Oh I wonder why these two primaries still look nice and shiny when all 6 others are golden brown?' I guess it has been like this for at least 4-6 months ever since I tore everything off the motor except heads and its components to replace gaskets this last winter. When I bought the car before I put it under it was definitely running A LOT stronger and on all 8, and that's when it was BONE stock.

So I just ruled out 2 out of 3 possible faults in the system. Now all that's left would be compression test? Right? I'm going to try and do that tonight when my car gets a little bit cooler to work on. But in all it looks like I'm pretty fucked. Unless there could be something possibly wrong somewhere else, it seems as my compression is messed up on those 2.

All I know about compression is how to test it. I probably do not even need to test since I ruled everything else out.. But I will just for fun.

My BIG QUESTION, is what could cause this compression/cylinder issue, and what are the possible solutions...

I'm torn between bringing the motor back to life completely, or just letting it be as is until next year when I can afford to rebuild and do a very nice forged 355..

Sorry all for the long post, I got some sad sad problems as you can see and I will CHERISH any and all the information you guys possess on this issue.

Thanks a million in advance,
FormulaJoe.

 

figure out what is preventing it from firing.. even if they are fd up they should still fire

 

Ya might be the injector harness, going to get a noid light. I ruled out spark on 1 cylinder and the injector isn't bad.
Going to a festival today so I won't be able to check anything else until Sunday. Suggestions on what to check for when I can get around to it?

 

did you get this fixed?

 

I figured out the number 8 cylinder was indeed firing, but it is off or something, it was not firing like it should. The plug was covered in carbon and so was my primary on my header.. The #2 has completely puzzled me and I did not ever figure it out.. I used a noid light and it blinked, I switched out injectors and nothing, I have spark, so I don't know what is up with that. And in the midst of trying to figure it out, my car started knocking like crazy, on my way back to my place it was bucking back and forth when I accelerated and backfiring out the intake and exhaust. It was a horrible knocking noise and sporadic backfiring.
If you have any ideas then please chime in, but I've given up spending more money on this engine when it has 140k and me and the previous 2 owners drove the **** out of it. It's time for a rebuild so that's what I'm gathering parts for now..

 

Sounds to me like u have a bad exhaust valve. Put some air in the cylinder when both valves are closed and see where the air comes out...TB exhaust egr ect.

 

I'd check to make sure the plug wires are are the corrects posts of the opti.

 

I even thought that when I looked up the order and was gonna check, number 2 and 8 are right next to each other so I thought that was it. Unfortunately they were correctly placed.