94sleeperZ

A couple months ago I posted on here, and got a couple good ideas, but i am still having trouble. I am pretty mechanically inclined. Here is the issue, when the car is cold, runs great and at WOT????? But when its gets warm it wants to have a small miss?? And when you blip the throttle it back fires threw the intake and sometime back in the exhaust??? also wants to shift into overdrive to soon??

I have replace
Opti
ICM
MAF
Plugs
Wires
Coil
Fuel filter
New intake gaskets 1 year ago

It is not throwing a CEL??? I have taken it to two shop with scan tools and they cant find anything that sticks out?? It has good fuel pressure too?The car sits most of the time, it has 89xxx on it? I have had this problem for 2 years it hasnt got any worse but still there. I am going on the Hot rod Power tour and will be driving 5 hrs one way then back. I am at a lose and will more then likely be selling the car when i get home. This car is my baby and I love it, but just tired of this problem and throwing money at it. The only thing it could be would be one of the four o2 sensors i would think? Any other ideas would be great thank you.

gatorhead

iTrader: (4)

I didn't know that the 94's had 4 O2 sensors.........

If it is cutting out only after getting warmed it could be several things. NEVER solely rely on the stock temp gauge when you think it is hot, cuz it probably is. If it is getting too hot in the engine bay components will fail via heat soak. Even a good sensor has thermal protection built into them and will shut down when/if they get too hot. I just found this to be the source of my problems. I thoroughly flushed the block, radiator and heater core and got all kinds of sludge out of it. I also found that while the thermostat was opening, it was only opening slightly not allowing enough coolant to circulate.

My suggestions are as follows, if you havent already done them:

ICM COOLING MOD! While you have ICM off have it checked! Also verify all four wires that go to the ICM are getting what they need! Black is Ground, the red is 10+ v dc, the white with black is same and the solid white is 0-5 volts toggling AC.

Make sure your cooling system is in good order, this also means checking the temp sensor in the water pump! Clean it up with scotch brite after you verify it is good!

What brand opti did you use?

95_z28

You seem to be having the same problem mine was after my longtube install. after changing all my plug wires and making sure they wasnt close to my headers, it fixed it a lil bit.
Then I checked my Vacuum lines and changed my driver side o2 and problem cleared right up. So check for a cracked line and check your o2's and.

CEL light work? I got my car my light was blown.

Paul Bell

iTrader: (9)

Fuel purge acting up when hot?

A.I.R. acting up when hot?

EGR acting up when hot?

94sleeperZ

Thanks, I will look into the icm issue, the motor does get hot, but the fans kick on when they should. I have a 180 degree thermostat but it still gets hot when I am at a light, when i am driving it cools back down. I am pretty sure its not a head gasket because it would really overheat but it comes back down everytime. It just odd, because i cant tell if its a heat soak issue or a sensor/computer/timing/fuel &air issue???? I am at a loss, plus i cant figure out why is shifts into overdrive to soon. It also seems like it doesnt shift down when i give it gas as soon as it used to. Almost like its lacking power. Thats why i thought it was the opti

94sleeperZ

Never heard of a fuel purge? How can i test that? The egr might be something, like a clogged cat maybe? But i thought if it was egr it would do it all the time?? and it still does have the air system hooked up, what goes wrong with that stuff? Do you think with the cold air intake, the aftermarket intake elbow and free flow exhaust is enought to mess with the timing and fuel&air ratio to cause it run like crap?

Paul Bell

iTrader: (9)

It's number 7 here. One end sees vacuum.