| Re: Problem with the 308 GTSi | <– Date –> <– Thread –> |
|
From: clyderomero (clyderomero |
|
| Date: Wed, 14 May 2008 13:48:20 -0700 (PDT) | |
Youi may had enough valve float to damage all the valves on one side
Enough to cause no compression/power on one bank
You need to get a good chk on that bank
Introduce a table spoon of oil down each cyl proir to doing test and you should
have a reading no different that 15% between each cyl
Clyde
Sent via BlackBerry from Cingular Wireless
-----Original Message-----
From: georgedodson [at] comcast.net
Date: Wed, 14 May 2008 20:38:24
To:clyde <clyderomero [at] worldnet.att.net>
Cc:The FerrariList <ferrari [at] ferrarilist.com>
Subject: [Ferrari] Problem with the 308 GTSi
I wrote earlier that I had a problem with my 81 308 GTSi. I was pushing a bit
and the engine died and I am debugging the problem. I forgot, or was too
embarrassed to mention that, being used to the very narrow shift gates in my
Miata, I missed an upshift and ended up downshifting. The engine revved high
but I think it stayed below 8K before I got the clutch back in. She coasted to
a stop and after cooling down started with a very lumpy idle which is not
stable. It wants to die, then surges up to ~2500 RPM. The engine has
essentially no power. I did not hear any bad mechanical sounds during the
incident. The engine spins freely and has good oil pressure. I did a
compression test and got about 160 on the 1-4 Bank, but it was hard to get the
long tube into the 5-8 Bank due to the 5” of clearance to the body but I will
try again. If I get reasonable compression I will assume that the valves are
OK.
Initially, I assumed that I had some kind of ignition problem.
Preliminary test showed that 1-4 Bank fires driving the engine to a rough lumpy
idle with periodic surges to ~2500 RPM, pulling the Coil HT kills the engine
and pulling the 1-4 Bank Coil HT lead has no effect on performance.
I cleaned the Ignition Control Module (ICM) and cables – no effect
I swapped the 1-4 Bank and 5-8 Bank ICMs – No effect
I swapped the Ignition Coils/Leads – No effect.
I examined the 5-8 Bank Distributor. It looks “OK”. Cleaned and scraped
deposits and “ohmed” leads. All “OK”. Replaced – No Effect
Measured Spark Voltage; > 30KV on 1-4 Bank but less, only ~20KV on 5-8 Bank,
both measured from coil to ground with spark gap tester. Also, with HT lead
off I saw internal arcing in 5-8 Bank Coil, so I replaced 5-8 Bank Coil. – No
effect but didn’t expect one after the coil swap had no effect. Spark from HT
leads to ground is ~ 1”. I tested for rotor breakdown by placing HT lead on
each rotor at the center pickup point. No significant arc to rotor, therefore
no rotor breakdown to ground.
>From the flywheel timing inspection port, the marks are hard to see but I see
>some kind of mark with a timing light with spark pickup from 1-4 coil and 5-8
>coil. Timing marks run off to the right with spark advance, as expected. This
>would seem to exonerate both of the Flywheel TDC pickups.
Odd things-
• The more warmed up the engine is, the harder it is to start
TDC scribe marks on the back (engine side) of the intake cams drive pulley seem
~90 degrees apart but that is qualitative, they could be 1-2 belt teeth off.
Pulled individual spark plug leads. Removal of each of the 1-4 Bank plugs
causes similar engine stumble. None of the 5-8 Bank plugs have any effect. The
5-8 Bank exhaust manifold does not heat up.
Measured fuel pump pressure at the Fuel Injection distributor. Initial surge
was to ~40 PSI but after ~ 1 second came up to ~120 PSI.
Sprayed starting fluid into the air cleaner with only the 5-8 Bank Spark plugs
installed. No hint of starting.
Swap Ignition Distributor and Spark Plug Wires and sprayed lots more starting
fluid past the Fuel Injection (FI) plenum and got one backfire.
I do not see how in a throttle body Fuel Injection system there could be
delivery to only 4 of the 8 cylinders, all 4 being in one bank of the V-8. I
tried to loosen an injector but it started to twist the delivery tube, so I
chickened out.
Conclusion: I have skipped/slipped a tooth or teeth on the timing belt on the
5-8 Bank (at least)
Questions:
A) Am I missing something obvious?
B) With the plugs out, can you turn the engine by hand once you have the belt
covers off?
C) Are the timing marks obvious with the belt covers off?
I have no experience with fuel injection, just Webers and SUs, but have the
Bentley book on order. I have no experience with Ferrari engines, short of what
I have done and what I saw of the belt-change done at the shop when I bought
the car. I do have about 30 years experience restoring sports cars (Jags, MGs,
TRs, Morgans)
Regards,
George
_________________________________________________________________
To unsubscribe or modify your subscription options, please visit:
http://lists.ferrarilist.com/mailman/options/ferrari/clyderomero%40worldnet.att.net
Sponsored by BidNip.com eBay Auction Sniper
http://www.BidNip.com/
and F1 Headlines
http://www.F1Headlines.com/
-
Problem with the 308 GTSi georgedodson, May 14 2008
- Re: Problem with the 308 GTSi clyderomero, May 14 2008
- Re: Problem with the 308 GTSi Jeff Greenfield, May 14 2008
-
Re: Problem with the 308 GTSi Doug and Terri Anderson, May 14 2008
- Re: Problem with the 308 GTSi clyde romero, May 15 2008
- Re: Problem with the 308 GTSi georgedodson, May 16 2008
Results generated by Tiger Technologies Web hosting using MHonArc.