[V8] Low compression - Baffled

[Ed Kellock]

I worked on one a while back that had a bad ecu temp sensor.  It would crank
unevenly and not start.  We did some of the basic checks.  Then we pulled
the plugs and they were stinking wet with fuel.  Cleaned and dried them and
treated the thing like a carburetor engine that's flooded.  Finally got it
running.  Could this be your case, with too much fuel causing the
compression problems because the cylinders are washed with fuel?

Ed

> -----Original Message-----
> From: v8-bounces at audifans.com 
> [mailto:v8-bounces at audifans.com] On Behalf Of 32vquattro
> Sent: Saturday, February 17, 2007 5:47 PM
> To: Tony and Lillie; V8 Audi Fans
> Subject: Re: [V8] Low compression - Baffled
> 
> 
> Start with the basics. Is it getting fuel? How about spark? 
> How does oil look? Get back to us with these results, and i'm 
> sure we(us as a collective list, that is) can figure this out.
> 
> 
> 
> ----- Original Message ----- 
> From: "Tony and Lillie" <tonyandlillie1 at earthlink.net>
> To: "V8 Audi Fans" <v8 at audifans.com>
> Sent: Saturday, February 17, 2007 7:18 PM
> Subject: [V8] Low compression - Baffled
> 
> 
> > Fellow V8 Audifans,
> >
> > I may have come to the end of the V8. I'm completely 
> baffled, and I'm 
> > no
> > stranger to these car.
> >
> > I have a 1991 V8 with 325 K miles, in pretty good 
> condition. It's an 
> > auto
> > car.
> >
> > It ran great up until about two months ago. It's an 
> occasional driver, 
> > so
> > sometimes it will sit for two weeks or so. Anyhow, after 
> sitting about two 
> > weeks, it wouldn't start. I drove the 4kq and let it sit 
> for a while. I've 
> > been poking at it on and off, but now my 4k got wrecked 
> (I'm OK, but I'm 
> > still dealing with the ins), I have decided to try to get 
> this car running 
> > again.
> >
> > Of course, right off I noticed that the car was turning 
> over too fast 
> > and
> > not evenly (low compression in one or more cylinders), so 
> the first thing 
> > I did was to check the valve timing. I did the TB about 15k 
> ago, so right 
> > away I assumed I screwed up the tensioner or something. 
> Well, not the 
> > case. I've checked the timing with the mark on the pulley, 
> and the dots on 
> > the chain sprockets, Dead on. Oh, and I verified the Crank 
> mark with as 
> > being TDC for # 1, as that was another thing I recently 
> dealt with on the 
> > 4k.
> >
> > So, I did a compression test, and here are the results :(  Keep in 
> > mind
> > that this is a cold engine not run in about 2 months. I use 
> the five pump 
> > method when and engine is cold, using a remote starter switch.
> >
> > #1: 120 psi
> > #2: 120 psi
> > #3: 40psi
> > #4: 45 psi
> > #5: 50psi
> > #6: 15 psi
> > #7: 90 psi
> > #8: 60 psi
> >
> > The funny thing is, If they were all down I could look ofr 
> an intake 
> > or
> > exhaust restriction. But, with them not even, I don't know 
> what happened. 
> > And, it was rather sudden, as the car ran great before. I 
> drive it hard 
> > (5000 RPM or more each shift till at speed) and would 
> notice one or two 
> > cylinders down. I would also suspect this negates the 
> chance for carbon to 
> > build up :)
> >
> > So, anyone out there have any ideas for me?
> >
> > The car does have oil in it, coolant is full. I do have spark and 
> > fuel,
> > these were the first things I checked for.
> >
> > Tony Hoffman
> > _______________________________________________
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> > Have a V8 answer? ... Please help others by adding to the 
> KB ... all 
> > contributions welcome!
> > 
> 
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