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Car intermittetly stops firing on 2 cylinders

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00 Agent

15+ Year Contributor
173
1
Aug 7, 2003
TexasUS
Occasionally when I'm driving the car will suddenly bog down and start running like a lawn mower. I've found this to be because cylinders 2 & 3 are either getting no spark or no fuel. If I turn off the car and wait for the ECU to kick off then start it back up it runs fine. What's really wierd is that a couple times I've had to do this the ECU would never turn off after I turned the key off and I had to disconnect the battery. So what do you think? Coil? ECU?
 
If you hadn't mentioned the bit about the ECU not resetting, I would have said coil. Now I wonder if you have the 1G leaky-capacitor problem, instead.

- Jtoby

ps. if I turn out to be right, then this is a great example of where including a few extra details makes it easier to get help; if I turn out to be wrong, then this is a great example of why you shouldn't reply if you haven't experienced exactly what is being asked about
 
Not sure how old the wires are, they are the ones that came with the car... (I've only had it for about 3k miles)
 
Mine did this a while back. It was the ECU. If you can find somebody with the same ECU, try borrowing it to see if that fixes the problem before throwing wires and plugs and coils and transistors...Also I am not saying go buy a new computer, just see if you can find somebody close by with one.
 
Well, I don't know anyone with a '90. My brother has a '93 but that won't do me any good. :mad:
 
I just this weekend had the same issue. I found it to be the power transistor and the fuel pump.

First, using a voltmeter get the output codes for the ECU. Does it give you any bad codes? Including one that says the ECU is bad? Doesn't always detect the ECU. If you don't know how to do this, go buy a haynes manual. It'll step you through it and other procedures for checking other electrical components. I think you can get the ECU checked at the dealer also, but not sure.

You may not have the parts like I do, but here is what I started with and changed from a good car to root cause it:

ECU
Fuel relay
Plug Wires
Power tansistor
Coil pak
Throttle body
Fuel pump

I initially thought it was solely the spark, but found the car would idle until I gased it. Then it would die. Lack of fuel.

Best of luck.
 
Well last night it started running really rough then just died on me. Won't start. I am getting fuel so I'm assuming either the coil pack or ECU crapped out on me. I'm going to replace the coil this afternoon and we'll see what happens...
 
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