Is my computer overheating?

Bolt

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I found a strange situation and was wondering if anyone else ran into this.

Aftermarket items installed:
Paxton Super Charger
Bellanger Headers
Random Steel Cats
Corsa exhaust

  • I drive the car or let it run for 20 minutes the engine compartment is up to full operating temperature.
  • Leaving the hood closed. Shut the car off for 10 minutes.
  • Start the car and try to drive it, it backfires and misses terribly.
  • I open the hood for 20 minutes to leave everything cool down.
  • I then start it and it drives perfectly.
Here is what I think is going wrong:
Either my computer is getting to hot and not functioning properly
Or the Fuel/timing box for the Paxton Super Charger is getting hot and not working properly.

Here is why I say that:
  • I started the car leaving everything heat up.
  • I tried driving it. It missed.
  • I open the hood and checked the temperature of the boxes (185 F)
  • I put a fan blowing on the two boxes for 5 minutes
  • The car ran fine.
What should I do?
  • I was thinking of cutting a 5 inch hole in the hood fake vent over the brake master cylinder. To leave the hot air rise when car is not running.
  • Install a fan blowing on the computer. Running ductwork of course.
 

FE 065

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Maybe try insulating around the Fuel/timing box? A box over that box?
 

Purdue_Boiler_Viper

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Could be a lot of things. I'm in the electronics industry, and I can tell you that most devices can take 200 deg F with no problem, and are rated to 185F. So, 185F would not concern me too much.

I would start with the connectors going to the PCM, and the power distribution center. Get some contact cleaner / lube from radio shack and clean those up. Also any other connectors associated with your blower and engine controller. I'd check any Paxton electrical connections closely.

Check your spark plug wires. BTW, is the car setting any codes?
 
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Bolt

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Could be a lot of things. I'm in the electronics industry, and I can tell you that most devices can take 200 deg F with no problem, and are rated to 185F. So, 185F would not concern me too much.

I would start with the connectors going to the PCM, and the power distribution center. Get some contact cleaner / lube from radio shack and clean those up. Also any other connectors associated with your blower and engine controller. I'd check any Paxton electrical connections closely.

Check your spark plug wires. BTW, is the car setting any codes?

All connectors for the Paxton where eliminated and wires were soldered.

All connectors for the PCM where removed and repluged. All where seated properly.

No engine codes are being displayed.


I need to check closely the temps. I may be pushing over 200 degrees at the bottom of the PCM. Remember the exhaust is right there and the Cat is not far away. The steel in that area will burn you.


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Spark plug wires? Hmmm, They are new. Do you think heat will do this? I was thinking the same thing. The wires do seem to cross talk since they lay against each other..

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Purdue_Boiler_Viper

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I was just looking at your build log. Good Job!!! I have the RT high flow cats, and the temp is much cooler now than before, even with my Roe SC. So, If it is real hot at the PCM, something is up. Are you running the stock PCM?

Plug wires would just be an obvious next check. In the electronics world, most problems come down to connectors, cables, and then soldering.

What year is your car? And, did the problems start immediately after the Paxton install?
 
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Bolt

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Are you running the stock PCM?
YES

What year is your car?
1998

did the problems start immediately after the Paxton install?
No, I ran it for 2500 miles or 5 Months. I had a fuel pump relay stick on my Paxton timing/fuel box. I replaced this box ($1,000) and this is when this problem started. Paxton said it is not their box. They said I have something else with the car going wrong. I realize I need to eliminate this box and put a Vec3 on it. That will be next. First I need to solve this problem.
 

Purdue_Boiler_Viper

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No, I ran it for 2500 miles or 5 Months. I had a fuel pump relay stick on my Paxton timing/fuel box. I replaced this box ($1,000) and this is when this problem started. Paxton said it is not their box. They said I have something else with the car going wrong. I realize I need to eliminate this box and put a Vec3 on it. That will be next. First I need to solve this problem.

So, you had a car that ran well. Then the fuel pump relay fails and the car is dead, presumably with no fuel pressure. You replaced the whole box containing the relay, and now it runs but misfires at high temp?

It seems everything is the same from when the car was running well except the Paxton box. Why would Paxton think that it is not their box?
 
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Bolt

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So, you had a car that ran well. Then the fuel pump relay fails and the car is dead, presumably with no fuel pressure. You replaced the whole box containing the relay, and now it runs but misfires at high temp?

It seems everything is the same from when the car was running well except the Paxton box. Why would Paxton think that it is not their box?

Fuel pressure is OK, That is another story. There are three fuel punps on the car with the Paxton setup. No harm done. Actualy the pump stuck on the on position.

Since the first box went bad and the second was bad even though the problems are different they are pointing the finger somewhere else.

I'll extend the wires and put the new Paxton box inside my interior of my car.

I think it is their box. They *** their boxes with epoxy and when the epoxy heats up it expands and moves the components around. It's common sense. Once cooled everything works fine. I told them this and they do not want to hear about this. Guess I am stupid.
 

Camfab

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In your build photos, youv'e insulated the headers and the frame rails near the steering shaft. Your current photos have them removed, is there a reason for that? Could this removal be part of your issue? I like how you documented the build of your Paxton install, from a "Motor Heads" stand point you answered many of my questions.
 
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Bolt

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THE PROBLEM IS FIXED!!!!!!!!

I insulated the exhaust rocker so the heat does not come up thru the sill. I also layed a sheet of insulation over the aluminum heat shield. I reduced this temprature by 30 degrees. The computer no longer sees a temprature of 170 degrees. I also drilled a 5 inch hole in the hood vent over the master cylinder for the heat to escape. Amazing how much heat is coming out of this hole. Also I moved the paxton timing box to the interior. Now the car runs and works great.

Heat shields are on the headers. The above picture was the only one I could find which shows the spark plug wires laying against each other.

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!
 

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