Handy930

I will try to make this short. 1979 with 112K. I have never had a bit of a problem with the engine until now. The car sat for 2 months. Ran fine before. Took it up to Road America and noticed a miss when I got on it hard. Finished the trip (800 miles) taking it easy. No miss unless I pushed it a bit. The car sat for 4more weeks. I concluded it was a fuel problem after reading Bruce Anderson's tech article about the evils of ethanol gas. Could not find the Swepco Fuel Conditioner he recommeded but put in a can of Sea Foam. The car seemed to start running better. Thought I would drive a few miles. Engine totally died. Tow home. Both pumps were running but somewhat noisey. Installed new filter, front and rear pumps, new relays. It started. Shut it off and the engine continued to run until it appeared it ran out of fuel. A few seconds. It did this several times. Took it out for a spin. Still missing and bucking. Got home without a tow. Now the engine on high idle (1500rpm) but shuts down with the ignition off. Not sure what to do now. Could the ethanol gas caused more problems with the fuel distributor or could the primary pressure regulator sticking? If pump pressure had been low(I did not have equipment to test pressure) the PPR would have closed up. With new pumps and I assume higher pressure the PPR should have opened up and could it stick? Anyway, I'm stuck. Any ideas? I will be away from my computer for a few days but will give feedback on ideas and what solves the problem. Many thanks in advance.

DWalker

Need more information:

What do your spark plugs look like? Pics help
How old and what type of spark plug wire do you have?
How much Sea Foam did you use and have you drained the tank, put in regular gas and run the car long enough to get rid of any Sea Foam in the lines?
I generically do not recommend the use of Sea Foam in fuel injected cars, there are products that work better with less impact to the system.
What specifically led you to conclude you were originally having a fuel issue? How did you rule out an ignition issue?
Have you checked for vac leaks?
When starting the car does it fire right up or does it crank a bit with a somewhat large sooty cloud blasting from the pipe when it finally does start?


My guess is that you are going to need to seek a knowledgable service center, which might be hard to do as many techs these days have barely heard of CIS let alone actually worked on it. Without the more specialized tools to properly check line pressures, exhaust gass content, etc. it might be somewhat difficult to narrow this down. However, I would start by performing a vacuum/boost leak test, a careful exanination of the sparking plugs and wires, and fresh fuel then go from there.

Mark Houghton

My guess is that you are going to need to seek a knowledgable service center, which might be hard to do as many techs these days have barely heard of CIS let alone actually worked on it. Without the more specialized tools to properly check line pressures, exhaust gass content, etc. it might be somewhat difficult to narrow this down. However, I would start by performing a vacuum/boost leak test, a careful exanination of the sparking plugs and wires, and fresh fuel then go from there.

...and if you have the gauge setup, do check the system and control pressures at the WUR. These in conjunction with a %CO exhaust tester to see where your AFR mixture is setting at. Your WUR may have finally crapped out on you.

Handy930

Here is the latest. The car starts right up. No soot or smoke. Very high idle. I blocked the AAR line from the IC and idle returned to near normal. Tried to drive and all seemed OK until I stepped on it a bit and it went flat. Drove easy back home hoping it would not die completely and require another tow. The plug wires are not very old and are OEM braided. Plugs look OK. Running Platmium. Obviously the AAR is not functioning, but that should not cause the engine to stall when the air inlet is blocked should it? The problem just continued to get worse, but seemed to improve with the Sea Foam( I normally use Techron)until it died suddenly, and I assumed it was fuel by the sound of the pumps. I even replaced the CD unit with my spare and no change. I have CO tester but have not used it yet. I do not have gear to test pressures. Where is a good source? How does the WUR normally show failure? I have a factory Turbo supplement manual and assume I can check out the system myself if I can acquire a testing system. I will try to run it long enough to get a warm CO reading. I am in Des Moines, Iowa and as far as I know I am on my own. I have always thought I could run down to ImagineAuto if I ever needed serious help. But sadly no more. What is a good way to check vacuum leaks? Thanks for the input.

Mark Houghton

Chances are you've got nothing more than a simple boost leak. Will wreak havoc with your AFRs' by letting air in where it shouldn't be when you're not boosting, and letting air escape when it should remain contained under boost. Will cause wide swings in fuel mixture and flat running/no power as you've described. When is the last time you removed your IC and checked all O ring seals, etc?
You could try the old carburetor cleaner spray-for-leaks test, spraying that crap at all sealing junctions (including vacuum connections) and listen for changes to the rpms. Might help to narrow it down.
As for your AAR action and the high idle at startup, I presume that's a cold engine? If so, it's working properly. Even if it was stuck open, causing high idle in a warm engine, that shouldn't result in your overall running problem.

DWalker

I do a boost leak test by pressuring the system at the turbo inlet to about 15-20psi and loooking/listening etc for the leaks. Before you do this LOOK for cracked/loose hoses, bad diverter valve, etc. as the usual suspects.
Replace your plug wires and swap out the plugs, just to eliminate them as the cause of your original issue.

Something to ALWAYS remember with a boosted car is that if you have any misfiring at ALL under boost the first suspect is ignition, as under higher rpm and boost the chances of spark blowout are high, and even higher than with old plugs and plug wires, so its cheap insurance to simply replace them with nice fresh units.

Handy930

I'm back and ready to dig into the problem. I appreciate all your inputs. I agree that a miss under boost could be a plugs and wire issue. But the engine totally died and would not start. New pumps and filter and it stackarts. Seems to run OK for the first few minutes, then goes flat on increased throttle and runs rough. I haven't had the nerve to go to far and have it quit again and have to be flat bed back. I talked to John at Deloren and he thinks the it is not a fuel distributor and more likely the WUR. I don't totally understand the WUR. But on a warmed engine the WUR should be returning the control pressure to normal and letting the distributor PPR be the only control on the AFR. I need to do some pressure testing before I start throwing $ at the problem. Anyone know an inexpensive pressure test setup?

911rudy

Believe it or not JC Whitney has a desent gage and hose set up for about $70. It has all of the fittings that you will need and the gages.

Handy930

What I found today. Plugs are black. Car starts but has a high idle CO reading of about 9%. Took the cold start valve out of the circuit. No change in CO. I am becoming convinced that it is the WUR. Is there anyway to go without rebuilding. Pelican shows the
WUR no longer available. Will probably go the rebuilt route with Deloren Auto Parts. Thanks for the pressure guage info.

Mark Houghton

Before you write off the WUR as being defective (and it well might be) 9% CO is definitely eye-watering pig rich. Has anyone messed with your mixture control screw on the top of the fuel head? Just a small turn (4mm allen wrench?) can make a huge difference in the CO. You may be able to turn the screw counter-clockwise and lean out the mixture at that point, if for some reason it's been adjusted in too far. I'm not saying that will compensate for a bad WUR, but wouldn't it be nice if that's all it is...and out of adjustment control arm?

A930Rocket

Did you replace the black plugs with new ones?

Handy930

Hooray! Back running. Not sure if I had multiple problems at the same time but doubt it. For all of you that directed me to ignition you were correct. This is what I found. One wire going to the coil was hanging loose. From what I can tell it was loose(nut not tight) and had been burning away for a long time. The eye fitting was now more like a hook and had the shape of the hex nut on the inside. I would check spark and it was there when the car was running rough. When it died the first time it restarted the next day. Ran rough and died again. This time I found no spark and started to dig into the lead from the distributor. That's when I found the loose wire. I think the black plugs and the high CO were the result of very weak spark. I'm heading out for a full test and will recheck the CO but I can tell already that exhaust smells like it should. Will at least I have new pumps and a filter. Not ever sure they were ever a problem but I should be good to go now without worry. Thanks for all the input. Very appreciated out here in Des Moines with no dealer or wrench to go to when I'm stuck.

911rudy

This is a good lesson to all of us who, I am one of them, have a tendency to swap out perfectly good parts in the sincere belief that it will cure the problem. As we all are aware fuel, spark and air are the ingredients that make things happen and if we were all smart we would always start with the easiest tap, wiggle, pull and poke method of investigation. If a car has been running fine before the last outing and then begins having terrible problems the odds are that it is something simple. Obviously there are exceptions to the simple rule but to start there can save a lot of time and money. Bravo for solving the problem Handy!!!!!!

A930Rocket

^^^ +1

I swapped out an alternator only to find out the pos wire on the starter was loose...

Last930

+++2

I once spent an enormous amount of time and expense diagnosing a missfire that occurred only at full boost - testing fuel pump flows, sending the fuel distributor for testing, etc. only to find that I had a bad sparkplug that would work fine at low boost but break down under higher pressures.

The moral of the story - start with the easy stuff!