91 Talon AWD loss of power

[OreoTsi]

MY friend has a bone stock 91 Talon AWD. Car has 90,000 miles on it. He has an intermittent problem while hes driving. When driving normally, the rpms will suddenly start to drop, as he applies more gas the revs keep dropping but the car doesn't stall. It just has no power at all. The problem comes and goes, but we were able to log his car while it was doing it. What was happening was he was getting extreme counts of knock, and NEGATIVE timing advance! I don't have the logs saved, but could pull more if that would help. His gas mileage is really really bad also, to the tune of 100miles a tank.

To me it seems that hes running pig rich, which is causing rich knock which is telling the computer to retard timing, but its doing it so much where the car just isn't makign any power. However, why would this be happening on a stock car?

Anything we can try? He's done plugs, wires and PCV. I'm thinking we should change the fuel filter, do a boost leak test, and also a compression test just to cover all angles. However if its fuel related, wouldn't it happen all the time?

Looking for ideas, let me know
Gregg

 

[steve]

My friend has a bone stock 91 Talon AWD. Car has 90,000 miles on it. He's done plugs, wires and PCV. I'm thinking we should change the fuel filter, do a boost leak test, and also a compression test just to cover all angles.

That's a good start but it may also need a new O2 sensor, new knock sensor, and the rest of the long term maint done.

Steve

 

[ROOKIE1]

1991 . Could be capacitors in ecu . Seems to be pretty common 1g problem .

 

[steve]

1991 . Could be capacitors in ecu . Seems to be pretty common 1g problem .

More than common, every 1G ECU will suffer from it unless they are replaced before they leak or short out.

Steve