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flightlead404 flightlead404 is offline
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Join Date: May 2015
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Originally Posted by solarispete View Post
Hi all,
I am having problems with my 1985 Euro 930 wondering if anyone can help.

The car seems to run ok when cold, when warmed up, when the turbo comes on, it hesitates and literally lags, almost cut out... It doesn't stall the car. I noticed when this happens, car idles higher than usual (around 1300 rpm). Sometimes, if I turn off the engine, wait a few minutes and start it up again, seems to run ok for a while.

Finally took it to my local Porsche mechanic. He suspected the WUR and sent to some shop in California to have it rebuilt... They told me the "diaphragm" was bad... Anyway, he put the rebuilt unit on and he tested it was good and then it went bad again. He's still diagnosing but can't seem to find the issue... Loss of fuel pressure when turbo is engaged. So far, he checked and replaced the following but still doesn't help...
1) vaccum lines (found no leaks)
2) replaced the two red fuel relays in front fuse box
3) replaced the black enrichment relay in the back fuse box
4) the fuel pumps were replaced about 6 years ago so there should be ok
5) replaced fuel accumulator

still runs poorly... if anything it's worse... he says sometimes he has problems starting... running too rich?

Any advice?

One thing he keeps insisting is that I am not using the right fuel. I use the Chevron 91 high Octane, which says that there could be 10% ethanol. He wants me to use Chevron 94 which does not contain ethanol. For one, it's $1.70/L in Canada and not all stations carry it. He insists that the ethanol is bad for classic Porsches. Any thoughts on this? I have friends who have 86 911 Carreras and Octane with ethanol caused no problems. BUT my mechanic believes the 96 Carreras have different fuel systems than the 930, so I don't know. Thoughts?
My first thought is your mechanic is randomly replacing parts trying to diagnose the problem by throwing darts at it rather than taking a considered methodical approach.

Second, I have experienced the same behaviour and it was due to a bad seal between the boost pipe and the intercooler.

Do you have a wideband? Do you actually know what is happening with your AFR? Are you going lean or pig rich?
Old 02-23-2018, 02:59 AM
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