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91 S-10 Running Horrible!

The Gare
09-11-2007, 01:22 PM
I have a 91 S-10, V6 4.3 that started running llike complete crap after running a bottle of injector cleaner through it. IT threw a SES light that said the MAP sensor, O2 Sensor and EGR were bad. I replaced all of them, plus the cap, rotor, wires, plugs, and fuel filter! IT is still running horrible. I have not checked the fuel pressure yet. It seems like it is missing, but it seems more like it is being starved for fuel. Also, when I start it in the morning, there is always white smoke at first. Not thick but like it was flooded or something.

Anyway, anyone have any ideas?

09-11-2007, 01:48 PM
What engine and engine code?
What were the code no?
What was your fuel pressure?
Did the codes clear and not come back or what codes do you still have.

The Gare
09-11-2007, 01:54 PM
It is an 91' 4.3 V6.

I dont remember the codes off hand, but they were for the EGR, MAP Sensor and O2 Sensor. I replaced all of them and the codes have not come back. Like I said, the fuel pressure is the only thing I have not checked yet. There are no codes any longer.


09-11-2007, 03:07 PM
There are multiple DTC's (Diagnostic Trouble Codes) for each circuit and component. Each DTC indicates which circuit the PCM recognized an out of range condition in. DTC's do not mean replace a part, they only tell you what circuit was out of range. It's up to the technician to diagnose what caused the DTC to set. One of the many benefits associated with DIY, (Do It Yourself) is to save money. GIY, (Guess It Yourself) gets expensive very quickly. Bottom line: Proper diagnosis is required to avoid unnecessary replacement of parts. When the DTC's reappear, write them down and post them here, we will help you diagnose the problem. In the mean while, check the fuel pressure. Low fuel pressure can cause any of those DTC's to set.

The Gare
09-12-2007, 11:47 AM
This all originally started a few months ago when I ran a bottle of injector cleaner through it. IT ran like crap for a week after that, then just fixed itself for about 2 weeks. Then one day started running like crap again. Incidentally, I was getting those codes before it started running like this. I was just ignoring them for as long as possible. They were all original parts.

I am picking up a pressure gauge from Harbor frieght today. Like I said, it is the only thing I have not checked.

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