My friend just rebuilt his motor and through on a turbo kit. He had the identical setup on his other car that he totaled so he is using his old ECU to break it in and check for other issues before he takes it to the tuner. The car will start up fine, Idles steady above 10000, run finee up and down the street (havent gone past 4500).

We took it around the corner maybe 2 miles from his house and as soon as we turned back, it started popping and missing randomly. idle drops down to 5-600 but stays steady there.
Plugs are ngk 7 gapped at .030
He is going to use borrow a dizzy to see if its not the coil or something else ignition related.
And hes going to swap the fuel filter since the car sat for almost a year.
NO CEL
Any other suggestions?

EDIT: Problem solved. New distributor seemed to solve it

 

Make sure the screw in the rotor button didn't back off.

 

gap the plugs lower 30 is way to high start at 20 and go lower from there

 

Sorry for being ignorant, but wouldnt this only be a problem while boosting?

 

Are you saying every time the engine is first started it runs fine until it reaches operating temps? Do you have a wideband installed? what is the afr's when all this is going on?

I agree if your not going into boost 20ths gap isn't going to help at all. If the kit was on a higher compression engine and now the compression is lower like so many boosted cars end up. a 40ths gap might be better during break in.

 

I have run .030 at close to 300hp with a healthy ignition system. You want your gap as big as possible better to start big and move down if needed.

 

Just because it's identical doesn't mean it's the same. You gotta remember once you open up a motor everything changes, even just removing the distributor will change everything. Just a few things to check for are timing, afr's, and map sensor (I had a map sensor problem before that gave me the same problems as your friend and usually happened when revving to 4k rpm). Another thing is like you said trying another distributor. Also, what program is he using? If he is using Crome, or the like, chips go bad from time to time and especially if you end up having some sort of electrical short or if the ecu is exposed to the sun because heat will also affect the chip.

CELs won't matter too much because most of them will be disabled. Your friend's practical last resort is a re-tune or at the least hook ecu up to a laptop, enable all CELs, and log to see what's actually going on.

 

If the chip was bad, wouldnt the problem start as soon as the car is turned on?

The only CEL disabled would be the O2. Everything else would be the same.

And he wants to get it retuned, but we the tuner told us to make sure its running right or he would charge the hourly rate to fix. Id rather try first with the means we have.

 

Bad chip doesn't necessarily show problems right off the bat, doesn't take much fuel to idle a motor. If it is a bad chip once you get to op temp, motor will lean out while driving because it'll be running the oem program. Once again, this is saying if chip is bad.

CELs, depends on the tuner's preference on what is and is not disabled.

Best bet is to log the car, but at the least check everything I mentioned. Also make sure injectors are ok too, I forgot to mention this earlier. It sucks that your tuner wants to charge you fees, I go to Church's and they now charge $190/hr but cap it at $380 max including troubleshooting (if needed) and being on dyno for more than 2hrs. There were a few times that we were on the dyno for more than 4hrs and were only charged the cap. Then again, this is maybe due to me being a customer for about 5 yrs.

Anyway, good luck and keep us posted.

 

I do not know what solved the problem but heres a few thing we did

5 gallons of 91 with injector cleaner. It reads under half now.

The sensor under the dizzy, the ect sensor, that single bullet style connector was loose. Squished down the connection a little. Still kind of loose though.

Replace the dizzy with a new ebay unit.

Coil measured at 2-3 ohms, but even the new one did??

Either way PROBLEM SOLVED

 

the car needs to be retuned
/thread

 

We needed to get the bugs out so we could take it to be tuned.
Making sure everythings right before hand means tuner spends less time chasing problems, more time making power

 

do you have a wideband on the car? could be running lean causing the problems

 

Sounds to me like this car is still running in open loop at operating temp with a poor tune.
Get the car to a tuner.

 

See coments above. Problem was solved. Likely cause was the distibutor