LouC wrote:
Wow you have gone through a lot of nonsense with this problem...
A few questions:
Have the mechanics verified a few key points:
Compression is even but high, are there carbon deposits on the backside of the valves (was that seen when the HG was done?) Were the carbon deposits removed from the valves and combustion chamber?
When the HG was done the valves were sent out to be R&R'd. I don't know what they actually did as part of this...other than new springs. (I'm not a mechanic so if I say something silly - sorry.)
When running, was it ever checked for a vaccum leak, vacuum at idle should be high and steady (18-22 or so inches of mercury). If not start looking for leaky intake manifold gaskets, leaky gasket under TB, loose bolts holding down TB, cracked or disconnected vaccum lines.
Yes. Vaccum is good and no leak has been found.
Was fuel pressure ever verified as OK?
Yes. Both fuel pumps were checked by previous mechanic. Current mech working it says pressure is good.
Was fuel filter dumped out into a glass jar and fuel checked for water?
FF was replaced 3 times. They said they didn't find anything.
Have the grounds for the ECU and battery ever checked to make sure they are all clean, tight and free of corrosion?
I don't know about this. I don't think so.
Has anyone looked at the anti siphon valve on the gas tank, these have a check ball valve that is there to keep gas from siphoning into the bilge if the fuel line leaks. If they stick partially closed the engine will starve for gas.
Same goes for the vent on the gas tank.
Yes. It was replaced by previous mechanic while attempting to solve this issue. Said it looked OK but replaced anyway.
Lastly you can try wiggling the connectors on the ECU and injectors to see if that makes the idle worse, sometimes a loose pin in the connector or one thats corroded can cause these problems.
Yes. Tried this too.
I had a similar problem with my 98 Jeep last year. Random low speed stalling, it would just shut off. The ECUs on them are known to have problems at about 15 years of use or so, bad solder joints. I went through everything (cleaned/replaced IAC, cleaned all grounds, tune up, CPS, TPS, etc). Turned out to be the ECU. Had that replaced no more stalls runs perfect again as it had for 14 years and 140,000 miles before it started stalling.
Right now this is probably the most likely suspect, but apparently there is nothing to indicate other than the fact that nothing else is fixing it.
In a boat, give me points n condenser, mechanical fuel pump and a nice clean Quadrajet 4bbl thank you very much.
good luck, I bet its one of the things mentioned above.....
Current status is that he just doesn't know. Same as the previous guys. Says that everything points to bad injectors but that doesn't make sense because they've been serviced twice as part of this and it's hard to believe that I got bad service twice unless the folks doing the rebuild are just clueless. Going to go ahead and have them cleaned anyway and also going to try to find a working ECM see if that solves it. If all that fails I don't know where we go from there...
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'99 234 Candia Funship, 5.7Gsi SX

