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86 951 stalls
86 951 cold starts fine. within about 5 minutes after warmup it shuts down. replaced dme relay and fuel pump. Is it then the dme? after 30 minutes of cooldown it starts again until warm then shuts down again. Suggestions?
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07-12-2012, 06:04 PM
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Vacuum leak that gets worse when it gets hot? Here's a good link on how to interpret vacuum gauge readings: How to Use and Interpret a Vacuum Gauge
I don't see it being the DME - because that's not affected by heat in the engine compartment. What you're looking for is something affected by heat. The obvious is that everything expands as it heats and contracts when it's cold - and that's what makes me think of a vacuum leak. The leak only occurs when the metal is hot and expands. Diagnose it with a vacuum gauge. If it's confirmed, then you have to chase down the location. It could be a connection to a vacuum tube; it could be a leak in the intake manifold (bad gasket?); it could be a bunch of different things.
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83 944 NA - Black on black 86 951 - Red - SOLD 7/21 16 Ford Expedition He who hesitates is lost. |
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07-12-2012, 09:20 PM
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Quote:
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86 951 blk |
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07-13-2012, 01:55 AM
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I did have a rotor burn out about a year ago which I found strange.
If it has done it again, what would be the cause of that recurring? |
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07-13-2012, 05:58 AM
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misaligned distributor cap? bad ignition coil?
how does it idle? possibly bad idle stabilizer?
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'89 turbo-s (2.7, wolf3d ems, garrett dbb turbo, tial 46mm, etc. fast!) |
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07-13-2012, 11:23 AM
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Quote:
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86 951 blk |
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07-13-2012, 05:51 PM
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I have now replaced coill, checked rotor which looks as new.
Swapped out DME with a spare, replaced plugs. car idles and revs great until it is hot. Ruled out TPS. The car doesn't completely shut down, it just stumbles as if it is running on 2 or 3 cylinders. Could the TPS cause this? My next check is vacumm. I have found no bad lines at this point. |
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07-14-2012, 08:12 AM
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Problem fixed!!!! I toook a shot at replacing the Air flow sensor and she's purring again.
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07-15-2012, 05:23 AM
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awesome, easy fix.
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'89 turbo-s (2.7, wolf3d ems, garrett dbb turbo, tial 46mm, etc. fast!) |
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07-16-2012, 10:19 AM
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Good thread, unfortunately I need it. My car stumbles inconsistently, but only when hot. One stoplight the car will almost die, save itself and hover around but not smoothly idle. Then it will be a fight to get past 4k, all the sudden it will rip up to redline. Next light, idles fine (a little high), a runs away smoothly. I'm really hoping not a vaccum problem (the last thing I want to do is trace that).
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07-16-2012, 12:39 PM
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Sounds very similar to my problem. Air Flow meter did the trick for me. Good luck!
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07-17-2012, 08:44 AM
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Quote:
It's odd, and I think it is vacuum related. Not to completely threadjack, but the symptoms are: Runs perfect cold (though I never get on it cold, so I couldn't exactly say that) When hot, runs on low throttle normal, cruising, etc The idle problem when hot seems to be better if I let the car come down in revs while in gear up to the stop (creating strong vacuum) If I smoothly come up to about 4k or so, then mash it, it sounds like a rev-limiter from under the hood (the type of popping rally cars make out the exhaust when sitting on the launch limiter). Does this pop three to four times, then takes off like a bat out of hell I think it's time for all new vacuum lines (probably the originals from 86), and even if the problem persists at least I won't have to worry about a vacuum problem for some time. |
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07-17-2012, 12:04 PM
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sounds like it could be a faulty tps.
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'89 turbo-s (2.7, wolf3d ems, garrett dbb turbo, tial 46mm, etc. fast!) |
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07-17-2012, 01:35 PM
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Quote:
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07-17-2012, 03:05 PM
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i've had a faulty tps that only showed fault after the engine got hot. testing it with a multimeter did not reveal anything in my case. just fyi.
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'89 turbo-s (2.7, wolf3d ems, garrett dbb turbo, tial 46mm, etc. fast!) |
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07-18-2012, 08:39 AM
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I have found TPS usually fails at about 2,000 rpm or so, not 4,000 as it is usually the switch. I had one go bad before.
The AFM can go bad at any RPM as it is a sliding fan type sensor. I was fortunate enough to have a spare on a parts car to switch out. Once agian good luck. |
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07-18-2012, 02:24 PM
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My haynes manual wasn't much help, but Clarks garage has a good write up on how to test both the tps and afm - I may get that done tonight (but probably will drink beer instead).
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07-18-2012, 02:57 PM
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By the way you can repair the AFM in some cases. utube has a couple of how to's.
I cracked my bad one open and could see the obvious problem after seeing the how to on utube. look here. Rejuvenating a Bosch Motronic Air Flow Meter - YouTube |
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07-18-2012, 03:31 PM
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Finally tested the electrical parts. TPS passed (didn't try it hot, so may still be a problem). The AFM failed miserably. Should have had 5V, got about 3 max. I was going to just take that as the impetus for converting to a MAF system, but even used I just can't justify the cost when I'm likely leaving the car pretty stock. I have a used working AFM on the way now, once it's in I'll take mine apart to try and fix it, to have a working spare.
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07-23-2012, 01:31 PM
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Curious to know how that works out for you. Please post results.
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07-23-2012, 04:46 PM
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My 951
My 83 NA
#3
