Random Hesitation?

[Ryan]

Today on my way home from the store my laser started to randomly hesitate and studder under normal driving, but only in 1-3 gears under 4.5k and only every once and a while. It would catch it's self and take off again. The turbo was spooling like normal according to my gauge, it felt like lack of fuel. Some times it has a hard time running when the engine spins down from accelerating or crusing. Its almost like it chokes out for a sec. and catchs itself and Idles back up again. It also studders slightly under hard accel. and dosent pull like it sould. Im only running 10psi. Anybody have any ideas?

[Glenn]

Well, we might as well start from the beginning: Fuel Filter, air filter, plugs, wires, etc.. all in good shape/been changed lately?

[Ryan]

yep, they were all replaced when I had the motor out.

[masta3]

im having the same problem... but sometimes the oil light pop-up..but there is oil in the car.. i did the spark plugs and spark plug wires... the problem went away then it came back.. should i change the oil to a heavier weight?

[Ryan]

What weight are you using, besides thats most likely not the problem. How low does your Idle go, that could be why the light comes on. Below normal idling and opperating rpms the motor isnt turnning fast enought to create enough oil pressure to turn off the idiot light. When its runnig take off the oil cap to see if you are getting oil to the top end at idle. Be carfull or it will spray oil everywhere. You may want to invest in a mechanical oil pressure guage just to be safe because no oil pressure is a very unpritty death to a motor. What did the old spark plugs look like? Did they show signs of oil consumption? You may be fouling plugs, Does it run rich? Any smoke out of the exhaust? If you fuel pressure regulator's diafram has a pin hole in it its dumping way to much fuel into the cyl. and it could be getting into the oil. Smell the oil for fuel.

[masta3]

i use 10w-50..the idle goes as low as 750 but the light doesnt come on then it comes on when u r driving aorund 3000 rpm when the turbo is about to kick in then the car starts studdering. but the light doesnt stay on it flashing on and off.. then sometimes when im driving it doesnt come on at all.. but this studdering is killing me... wondering why that keeps happening..my old spark plugs were fine no problems.. theres no smoke at idle.. and its not running rich..

[Ryan]

That viscosity seems fine, maybe a little heavy. How is your fuel pump? Is it rewired? How about your ecu, check the capacitors. The oil light coming on scares me. Its so hard to figure crap out over the internet.

[masta3]

yea i know what u mean..

[Ryan]

New development. It is only doing it when it is opperating temp. When it is cold its as smooth as a brand new car. Maybe o2 sensor or IAC valve. I will check them and post my results.

[IMissRacing]

Im having the same problem...Im going to start with replacing the fuel pump since I changed the filters and plugs and wires. Seems like a good excuse to get a 255 :D
Matt

[Ryan]

I just ordered a 255 also. I may have found the problem, a slight crack in the factory intake. That would explain why it only does it when its warm and runs great when cold. The comuter richens it up when its cold. That would also explain the lean tip-in. I just bought a 3in intake. I am picking it up this weekend. Then I'll know for sure. Check for vacuum leaks Matt.

[Ryan]

Just found the problem it was the factory fpr. Runs great now.
Thanks everybody.