Joined: Fri Apr 21 2006, 07:28AM
Location: England
Posts: 739
Coming back from a car show today I was coming up to a junction, so just coasting, power off, and the engine just died. I tried restarting and it turned over ok but didn't want to fire. Not wanting to gas it up, I left it 5 minutes and tried again. It fired up, ran for about 10 seconds and died again. so I waited a few mins, tried it again. It fired up again, this time a gave some revs, then set off home. It got home without problem. The only is it seems to be idling a couple of 100 RPM higher.
A few weeks ago I had it die whilst in traffic twice. Other than that it has run really smoothly.
It seems like a fuel starvation problem. I didn't get chance to check the glass fuel filter while cranking. Im wondering if there is something floating around in the fuel tank.
Joined: Fri Apr 21 2006, 07:28AM
Location: England
Posts: 739
Yes, I remember the push rod thread (can't find it though). Does this fit the symptoms though? It ran fine before and after stopping. Isn't it a bit random or is this how they go gradually. I am going to get a pushrod anyway, seems like a good idea.
I was thinking maybe its a bit of muck in the carb. I think I might pull the jets. Ive not had chance to look at to today. But ill start it up tomorrow.
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
Yes I'd say it fits the symptoms. With mine, the engine was more likely to act-up and stall when it was hot and idling or near-idle. Removing the air cleaner and looking down the throat of the carb while working the accelerator arm, I found that the accelerator pump wasn't shooting any fuel because the fuel bowls were empty. After the car sat and cooled off for awhile, it would restart after a little cranking to refill the carb. (I suspect that it couldn't pump enough fuel to prevent vapor lock when the engine was hot.)
If I could keep moving to keep the RPM up, the fuel pump could still pump enough fuel to keep the carb fed much of the time. Under hard acceleration however, especially WOT to pass someone, it could suck back enough fuel to run the carb dry and the car would lose power until I slowed back down.
The symptoms, both stalling at low speed when hot and losing power during hard acceleration, got worse as the pushrod wore down. I improved them temporarily by replacing the fuel pump and filter.
Joined: Fri Apr 21 2006, 07:28AM
Location: England
Posts: 739
Well I checked the pump pushrod and it was only about 0.005" shorter than spec, so clearly ok.
This is a 1976 400i engine with electronic ignition.
I took the car out tonight, it started and drove great.... for 4 miles, then cut out whilst idling. It then wouldn't fire. it turned over but nothing. it wouldn't even try to fire with ether spray can.
Heres what I checked at the side of the road.
I have fuel to my glass fuel filter. the carb jets are squirting. The mixture appears rich as the plugs were sooty. I am getting a spark at the plugs. I cleaned all the plugs.
By this time a mate turned up and we checked the spark from the coil lead. My mate reckons it looked pretty weak. By now everything had cooled down and when I tried it again it fired up.
Set off back home, this time got about 3 miles and it cut out again. We suspected maybe the coil so I put on a spare (an old one that could be just as bad).
After a lot of waiting and trying it fired.
So I hi tailed it home the short distance of less than a mile. Got it on my drive it stopped dead again. It was a definite dead stop.
So its getting more frequent, like something electrical breaking down? maybe when everything is getting warmer.
Im thinking maybe the coil? or what about the ignition module, or ballast resister?
Is there a module in the distributer that could be faulty? Although, the spark sort of looked weak straight from the coil lead from coil.
Any help/ideas appreciated.
I am going to get a new coil, ballast resister and ignition module anyway.
Can anyone recommend a make of coil? Don't MSD do one that works with a ballast resister?