engine coughing and spluttering
engine coughing and spluttering
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gtr-gaz

Original Poster:

5,281 posts

275 months

Sunday 30th October 2005
quotequote all
It's been almost undrivable today!

Can't stop it stalling. It will just not idle. Pulling away from a standstill and it just kept on trying to die on me. It was only by giving it a lot of revs and slipping the clutch was I able to get going.
It felt very erratic at low speeds.
When the engine did die (which was often) it was almost impossible to restart
How the battery kept up, I don't know!!

It's been fine up until today. any ideas?

Not taking it out again until this is sorted.

Gary

peterpsg

813 posts

263 months

Sunday 30th October 2005
quotequote all
I'd check the ignition first (MSD?), fuel pump & filter next, then I'd check the jets, etc, in the carb for blockages if you still have no joy... sounds like time to break out the old multimeter!

Hope you get it sorted before the winter really sets in...

tuxman

9,011 posts

267 months

Sunday 30th October 2005
quotequote all
Gaz when you restarted it did you have to pump the pedal or did it put out alot of black smoke on restart ?can you see float levels in carb windows if it is fuel they might show v-low ,what are the plugs like ? tell us more .simon

iandbeech

2,709 posts

287 months

Monday 31st October 2005
quotequote all
Hi Gary,

When we stopped at junctions/lights yesterday while in front of you, we could smell un burnt petrol.

I`m glad you still made it though, especially after your unplanned route!Hope you sort it soon.

Ian

davefiddes

846 posts

289 months

Monday 31st October 2005
quotequote all
Wonder if it could be something like a bust powervalve. My brother's Camaro behaved a bit like you describe when its power valve went on us in the spring. It's unusual to see clouds of black smoke and rubbish fuel economy on it so we knew something was likely to be up with the carb.

Power valves on Holleys are supposed to be pretty weak and give up with just a couple of good backfires through the intake. When we dug it out it the diaphram was all cracked and leaked.

That's be my second check after looking at the plugs to see that all cylinders were firing.

Dave

layada

112 posts

261 months

Monday 31st October 2005
quotequote all
Does sound fuel system related - suggest checking pumps and filters first, then float bowls.

gtr-gaz

Original Poster:

5,281 posts

275 months

Monday 31st October 2005
quotequote all
Thanks for all the help.

Have'nt looked at it yet. I was just so relieved to get home last night, that I just put it straight in the garage, came indoors and had a beer! Driving in the dark with it like that was very exhausting!!

I can't believe just how good those batteries are

I will check the fuel filter first though. I don't clean it out on every sevice , so am hoping it's just that. The last time I did, about 4,000 miles ago, it looked as clean as a whistle. Perhaps the crap that builds up inside them is invisible to the naked eye?

I don't clean the plugs or the air filter either!
What intervals to you all do yours at?

Anyway, I will let you know what I find out.

Gary

davefiddes

846 posts

289 months

Monday 31st October 2005
quotequote all
The air filter shouldn't need work until you've done 50k or so if it is a washable K&N part. The crud in fuel filters is usually visible black bits from the bottom of a rust petrol tank.

Boosted Ls1

21,200 posts

289 months

Monday 31st October 2005
quotequote all
I'd maybe go for the powervalve to. Look for black smoke/fuel at idle to diagnose a rich condition. Also check the float levels which shouldn't have changed on their own unless a brass float has punctured or collapsed. A damaged float will flood the engine. Remove the air filter and look into the 4 chokes from a safe distance. Are the main jets pissing in fuel/operating at idle or are the accelerator nozzles squirting? These checks will verify a fuel issue.

Boosted.

canam-phil

499 posts

288 months

Tuesday 1st November 2005
quotequote all
Gary

Instead of fuel I would go for an ingition fault. Just check that the inside and outside of the distributor cap is clean. I have seen some buildup of crud on some MSDs inside the cap that can track sparks and cause non-start/reluctant start and erratic running when they do start.

Phil

craig-ultima

243 posts

262 months

Thursday 3rd November 2005
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This is based on very limited experience:

I agree with Boosted. Check your fuel delivery at idle visually by staring down the carburettor with the air filter removed. But stand way back, and have a fire extinguisher at the ready.

A miniscule piece of crud can jam the needle float valve open and the fuel pumps will pour gas into the engine to the point where it will run really badly and stall at any speed. That happened to me. The piece of crud was a few hundredths of an inch across, but resulted in the cylinders literally being filled with gas. You could also have some crud in the vacuum channels or other parts of the fuel metering system that would result in bad behaviour at low speed.

I'm no expert. My general understanding is that sustained degradation is a fuel problem, and chronic or intermittent failure is usually an electrical problem. Where that thesis breaks down is when your coil starts to fail, when an ignition line starts to melt and you get intermittent conduction short circuits. Water in the electrical system would also cause gradual degradation. Probably other cases as well.

Keep posting your diagnosis. This forum is attended by all sorts of helpful people that really know a lot, and have been helpful to me on solving this type of problem.

gtr-gaz

Original Poster:

5,281 posts

275 months

Wednesday 16th November 2005
quotequote all
This afternoon was my first chance in trying to sort this problem out. cleaned the fuel filter first and then took it out for a spin. It started up ok.
Everything was just as it should be including oil pressure, so drove it to the garage to get some Optimax. I then drove it around and up the motorway when it had warmed up. It was ok just cruising at 70, but as soon as I put my foot down, instead of the usual mind blowing acceleration, it just felt, well, sort of flat realy. It did'nt want to pull at all. Felt as if it was only using about 4 cylinders. Very strange.

What was worse, was getting back home. It kept stalling at rounabouts again and just as I was 200 yds away from home it stalled again. This time when I restarted it oil pressure disappeared and a cloud of smoke poured out the air filter. I switched it off and coasted up the road and onto my drive.
The accusump gauge was also reading zero. I have tried turning it over a few times (it sounds perfectly normal), but cannot get any oil pressure at all. The oil light does not go out and the pressure gauge does'nt move.
Perhaps it's just coincidence to get two different problems at the same time??

Rang the factory. Ted was very helpful and gave me some pointers to be getting on with.
I'm no expert, but it looks a bit bleak from where I'm standing!

Gary

PS, might end up putting a diesel in it over winter

forgot to mention, I was supposed to be meeting a photographer this weekend for a feature of my car in a magazine! What a bummer!


>> Edited by gtr-gaz on Wednesday 16th November 17:59

steve_D

13,802 posts

287 months

Wednesday 16th November 2005
quotequote all
Try pulling the dizzy and see if you still have teeth on the drive gear.
The dizzy drives off the cam and in turn drives the oil pump so no start and no pressure could be related.

Steve

gtr-gaz

Original Poster:

5,281 posts

275 months

Thursday 17th November 2005
quotequote all
Thanks Steve. I will try that at the weekend.

Gary