well I normally fill up at shell........ but I was really low on gas so i filled up at a exxon station. The car was fine untill I did I burnout (witch I do all the time). Now the car will have a slight missfire at part throttle. if I Floor it it is ok, if its idling its ok... only misses at part throttle? I dont know if this could just be the gas or not, but its annoying.

Also the car is overheating badly. both fans are coming on (not sure if there coming on soon enough) but It almost got to around 250 idling in traffic. Only overheats sitting still as if the fans are not working.???



thanks

 

well if your overheating and misfiring do a compression check. when my headgasket was blown my car would missfire and coolant would boil out of the overflow tank.

 

well it has been overheating since I got the car, but yesterday I had to sit in traffic and it got almost to 250, And then once I got it home it got almost to 250 wile i lef tit running at idle checking stuff.
It startted missing before it got that hot though.
If I am sitting at a stop light when I take off it seems worse , it will sputter really bad.

 

Shouldn't be gas related.
When you were checking things out did the fan/s come on? If not you could check your CTS, fan switch, and give the fans 12v directly to make sure they work.

 

yes both fans were coming on, but now that I think about it one fan was cutting off and the temp guage was still close to 250.
SHould it get that hot even if the fans dont come on?? I have had a few vehicles that I never even had a fan on. Maybe the thermostat is sticking closed?

 

anyone have any ideas on the sputtering?
it doesnt cut out quickly, its more of a firing on 4 or 6 cylinders type cut out.

 

Have you done a compression check yet?

I would chase down your overheating problem before worrying too much about the misfire. They could be related.

 

It doesnt missfire all the time, but it does missfire weather the engine cold or hot. SO i dont think it would be compresion related.

 

anyone?

 

A compression problem will be there all the time. A blown head gasket or cracked rings wont heal themselves while the engine is cold then reappear when it heats up. Your 02 sensor could be going bad and your running you engine in a lean condition or maybe you have some injectors that arent working well. OHM them out too see if they pass (injectors).

just my .02

 

i drove it again and it seems to be like an ignition problem, I will check the injectors to though. seems to only happenat 1500-3000 rpm, could the distibutor cap or rotorbe missfiring or maybe the module inside?

What should the ohms read?

 

if you are too far advanced in your timing you might overheat. is your setup a tpi or TBI

 

IIRC stock good injectors should ohm out somewhere around 16-17. All 8 should also ohm out very close to each other.

 

TPI, the owner I bought it from said it has LT1 injectors.

 

i checked and all injectors are good.
I pulled the cap off the distributor and it was all black on the prongs and the rotor was to. I replaced them and now its missfiring even worse! I used AC parts

 

also if you have the lT1 ( 24 LB) injecotrs ...maek sure it was changed in the .bin file . Could be the issue ????

 

how can I tell if they really are Lt1 injectors?

It only will run fine for a minute then once I rev it above say 3500 it will just miss really bad all the time untill I cut it off for a while. I have replaced the cap, rotor, ignition module and plug wires. Also the collant temp isnt working! wtf!!

 

I am not sure how you tell , maybe others can chime in ?

 

What did you replace the ignition module with? I had replaced mine with an Accel unit, and it make my engine misfire exactly how you're describing. Maybe you forgot to use the dielectric grease underneath the module?

I really wouldn't doubt one bit if you have a blown head gasket based on what you're talking about in the rest of the thread.