car bogs misfires surges!!! i dunno!

[NeoHOUSHIN]

1993 3000GT VR4. I got problems with this car. No check engine light. Checked the ecu, good. Checked the wires, good. New spark plugs. Checked the coils, good.

I have a walbro fuel pump, 15t turbos, intercooler, intake and removed active-aero equipment.

I checked for boost leaks and i cant find any. Soap, water and a air compressor. Car idles rough. Starts rough. When revving the car misfires, also when trying to drive. The fastest I can possible get with the car is 20 mph. Please help!

[Stealthee]

Ok, you have 15t's and a Walboro. Do you have stock injectors?

[NeoHOUSHIN]

can the injectors actually be causing this big of a problem though? I do still have stock for now. I cant even get this car to idle properly let alone drive it on the street. I expected the stocks to keep the car idling fine and drive under 7 psi thats all i need for now. But if thats the problem. I'll go get em. Cause this car is driving me crazy right now.

[VR43000GT]

I would say you should at least have DSM 450CC's. On idle, you should be alright with stock injectors but not for driving. Sounds to me like some sort of igntion problem. Being that it is a first gen, have you every had your ECU rebuilt or checked? A car acting funky can often times lead to leaking caps in the ECU.

[Stealthee]

Stock injectors should be fine for 7 psi on 15t's.

It definitely sounds ignition related. What kind of plugs are you running and what are they gapped at?

[NeoHOUSHIN]

Running 6 Denso's (k20PR-U11). Guy at the store said they are already pregapped.

Also my ECU is fine, Already rebuilt and replaced with caps.

[JeenyusVR4]

Ya i dont think that your injectors are the problem unless they went bad then they would be but running only 7 psi shouldnt be the problem and they would also be fun to drive on if you just didnt hit boost. I would check either you ingition system or possibly your MAF. I've forgotten to plug it in sometimes after doin work and the car sputtered really bad at idle and barley cruised. It could also be a problem with a plugged up catalytic converter.

[Stealthee]

Originally Posted by NeoHOUSHIN

Running 6 Denso's (k20PR-U11). Guy at the store said they are already pregapped.

Also my ECU is fine, Already rebuilt and replaced with caps.

No plugs are ever really pregapped. I have seen "pregapped" plugs come out of the box and all be several thousandths difference.

Pull the plugs and gap them to about .032 then go from there.

[JeenyusVR4]

ya thats so true what stealthee always check the gaps before they go in the car. Ya i have mine gapped at .035.

[NeoHOUSHIN]

So we regapped at .032 and still the same problem. Called in my Dad, he also said it could be an ignition problem and said if I replaced the fuel injectors since I damn near replaced everything else. I said no. I had a 390cc set that I was going to replace in but first I had to see if the car worked. My dad put them in for me. And.... FIXED...He then went to go drink a beer and called me a "rookie".

Car ran like a beast and no more idling problems. I guess it gave it that go now. Can't believe that was the problem. Ether the injectors were bad or it just needed the extra kick to fire up. Wow....Thank you all for the help too!!!!!!!!!!!!!!!!

[Stealthee]

You are going to run rich with the 390's. They are not much larger than stock but they are still larger and will need to be tuned with an AFC of some sort.

[NeoHOUSHIN]

okay freakin... yea... the car is no good again!! I let the car sit for just 2 days... and now its back to the samething! The car still has a rough idle and sometimes stalls. still no codes. And as i rev the car in neutral it lags if i just slam the throttle but if i ease the throttle it misfires big time at 2000+. Anyone got any ideas? it's driving me crazy.

[quackmandude]

stealtees right, but 2days? somethings causng ur fuel system to clog ur injectors, or ur wiring in messing ur injectors up somehow. could still be ignition but unlikey. the 450cc might fix it but it sounds like something more in depth then injectors
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[quackmandude]

also man, it could be something as small as bad gas. i mean, the cars worked before with the fuel pump and stock injectors right??? did u fill up or put gas then it started again?? its happened to one of my friends, his truck was running like shit and it turned out that he filled up on bad gas, never know
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[NeoHOUSHIN]

I bought about 8 gallons of 91 from shell. So the gas is new in the tank. Also my fuel filter has been replaced too just in case. For sure fuel is running through as i see the inside of my pistons wet as i take the spark plugs out. Im guessing i could probably have a problem with my ignition? How could i possible check that? I swapped some coils with some other ones and it runs the same. I also tried swapping mafs with another and it responds the same. Could cam or crank sensors mess with this? I checked my timing and it hits right there. about 16 or so when checking unplugged and with the plugs bridged its 7. But it fluctuates. bout maybe 2-3. Also could a clogged cat cause this? i never checked but i do have a test pipe lying around... I probably test that and check up back here later. Thanks for the help! I'll keep ya'll updated.