2GNT rough cold starts and occasional stutter?

[rowlex]

Alright so got a 2G ESI here, when its started in the morning sometimes it will run for a sec, then die, then start-run for a sec-die, then it'll start and run rough then smooth out and run great. other times it will start and run rough and not die.

Also if im in like 3rd gear 2400rpms and floor it it will miss and jerk a bit. if it's above 2800-2900 rpm and i floor it it takes off with no problem...


any ideas? From what I have read the water temp sensor could be causing the cold start issue, i'll replace that when I get a chance.

Any other ideas? What could be wrong? Thanks guys!

 

[GSX Spyder]

the ECT sensor would be a great place to start, especially if it stumbles on a cold start. After that, I would check for intake leaks, and then after that I would check MAS MAF functions. If you have no means to test it, unplug it and do a cold start to see what conspires. If you have access to an OBD diagnostic tool, even though there is no MIL, check to see if anything is stored.

Cheers.

 

[rowlex]

the ECT sensor would be a great place to start, especially if it stumbles on a cold start. After that, I would check for intake leaks, and then after that I would check MAS MAF functions. If you have no means to test it, unplug it and do a cold start to see what conspires. If you have access to an OBD diagnostic tool, even though there is no MIL, check to see if anything is stored.

Cheers.

Thanks for the help! I just got my volt meter back so I am going to test the ECT. Working on figuring out how to test the TPS and IAC... I do have access to a diagnostic tool I'll try that too.

 

[VelocitàPaola]

What year is the car?

 

[BigRand]

Hey rowlex...I feel ya man...the weather out here has been crazy...not used to having to deal with all these cold starts.....I (think) have the a similar issue as you and I've diagonsed it down to a vac leak some where around the intake or possibly around my pcv valve.

 

[rowlex]

the car is a 95... i bought a replacement coil for it but come to find out it has a different connector. The car has a built engine (eagle rods forged pistons(8.7:1(or so)).

However I have another ESI that almost has the same problem, sometimes it will not run if i let off the gas but runs smoothly.

bigrand- yea the weather around here has been terrible, really somewhat depressing and just so dang cold! My cars are hating it atleast i don't have to ride my motorcycle anymore (got my daily driver running again).

is your car doing the same stuff?(could you give some detail) did you check/replace anything yet? I am just about to purchase a new isc/tps for it. I also think it is running a bit lean as i removed the plugs and they were more whiteish then brown. Do you gap them at .50? Thats what the manual said so thats what i gapped em at.

thanks for the help and quick replies!

 

[BigRand]

gap your NT around .45 just to be on the safe side. and still make sure to run the NGK BKR6E-11's

 

[rowlex]

ya i put some crap champions in it ### the only store that was open when i wanted to change em was shucks.

 

[Locke]

My car drives like poop with a gap above .045. Countless hours over a few days of pulling/reading/cleaning/checking/gapping my plugs and alot of driving has led me to find the butter zone as far as spark gap on MY car. The butt dyno tells me ~0.036" is perfect for some reason. Only thing I can figure why so small is a weak ignition. But it runs strong, good mileage.

 

[BigRand]

its funny though, because the NGK Bkr6e's (for a stock NT 420a) come pre gapped at about .40-.45 And usually if you just leave them their (after checking of course) the should be just fine.

If your turbo and looking for the one range colder BKR7E's then they come pre gapped around .32-.38.....make sure they are around .30-.32 before you put them in.

 

[DSMcrazy3]

Sounds like a plug/wire problem to me. I had the problem taking off with studdering when in the lower RPMS and not in higher. After I replaced them, I was good to go.

 

[rowlex]

awesome thanks guys.

My time is incredibly limited these days and I still have not had time to work on this car. Hopefully I can buy new plugs/wires and install them sometime this week.