After my 1988 4 cyl. 3S-FE Camry is driven for a few minutes the engine loses power. It is losing fuel pressure (have gauge attached). But for the first few minutes it runs fine. Actually, when you open the hood and watch the gauge when it has started malfunctioning, it's "hunting". At idle, it will rise to about 35 psi, and then go all the way down to about 15 psi, and repeats the cycle about once a second. The car will not accelerate when you push the gas pedal. Will just barely keep running. THought it was the fuel pump flaking out, (before seeing that wild fluctuation with fuel gauge attached). So I changed the fuel pump. Still does the same thing. The pump was in a terrible state of corrosion, so it was not wasted effort or $$$. I am sure it must be the fuel press regulator now. I removed it, and the port connecting to the fuel rail was narrowed down to about 1/8 inch, less than half of the unobstructed diameter! Looks like black carbon deposits. That deposit was easy to remove...but I suspect that the valve stem and seat inside probably has as much carbon buildup, and it might be making the valve stick, which will certainly cause a wild oscillation like this. A new press regulator costs $80 and I am kind of out of more $$$ for parts right now. The diaphragm is not ruptured. You can't dissasemble it to clean the valve seat and stem. So is there a product that will dissolve the deposits from 18 years of gas flowing through it?
- posted
17 years ago