Razor, I'm still interested in winning that beer!. Like Super said also fuel.

I had a VW Bettle I was driving around South Africa one summer, f' it was hot, anyway the car would crap out every 20 minutes of driving. I wanted to check out the engine but the heat coming off it was incredible and I had to stand back. Anyway one day I disconnected the fuel line then turned the key on for a while. After about 30 seconds a diamond shapped bit of white plastic came out of the line. What was happening was it would get closer and closer then after 20 minutes would stop against the carburator and completely stop the fuel. While I waited for the engine to cool so I could look at it, it would sink back down the fuel line and I'd be ok for the next 20 minutes.

I think fire a litre or two of Petol into a glass container by turning on the key and letting the fuel pump work, and like Super said look for rust or rubbish. Disconnect at the fuel distributor if you can.

Two things I would check - first check your cat converter - it may be partially plugged which would cause lack of power. Remove it and see if anything falls out on the inlet side.

Second, the 78 clutch assembly had a rubber vibration damper installed on the clutch plate. If it is coming apart, it could be causeing the problem. Do an inspection on it to see if you still have the old type.

Steve

Steve

I am not convinced it is a fuel 'restriction' problem ... because EVERY situation I have ever encountered with such a problem with rust in the lines, or patially-clogged fuel filter or failing fuel pump has always run fine on overun or steady-state (constant speed) and it has been on acceleration that the problem showed up!

Have you tested your new spark plug wires for end-to-end continuity and given them the 'shake' test? New wires can suffer from infant mortality ... it happens, BELIEVE ME!

Have you inspected the infamous connector where the green didtributor cable connects to the engine wiring harness?

I suggest puting your engine on an ignition analyzer scope to see if anything erratic show up on your ignition signals. If you happen to have an engine timing light with an inductive pickup ... preliminary testing could be done to all six spark plug leads to find an intermittent spark problem!

On Warren's point, this reminded me that my voltage regulator appears to be faulty and allows a spike around 2000-2500 rpm then returns to normal. A voltage fluctuation could potentially cause an ignition issue (more so if it fell). Checking voltage is easy and free (if you have a multimeter) - so you could rule that out too.

(edit) on reflection you said it got better when it idles and is fine for a while then is bad again. This makes my idea unlikely. I still say you test it - 2 mins work.

I generally yield to my esteemed colleague Warren and this day is no exception. But I will report that on at least one occasion the car with the rust-plugged fuel line would start and run fine for a while then would lose the ability to achieve 60 mph. It would operate at a (lumpy) steady state 40 or maybe 50 mph, but not highway speed.

If I to try to evacuate obstructions from the fuel lines of a CIS car, I would (unfortunately) disconnect each line at each end, and blow compressed air through. This is the only way, I think. But here's a hint: The largest volume of rust is usually found in the line with the longest vertical rise. Usually this is the long line from the gas tank to the engine compartment.

It's a but more work, but it might be worthwhile to drive the car until it's almost out of gas, then pull the fuel pump, drain the gas into a suitable container, then you'd have a dry tank and fuel line to clear. I won't be surprized if you see plenty of dull orange color throughout thsi procedure.

Still, I agree with Warren. These problems usually act like fuel starvation events. Your symptoms do sound a little odd since it is a random hesitation thing. I still think it is fuel related though, since an ignition system that cuts out like that would produce some exciting BOOMs in your exhaust. Perhaps your fuel pump is getting intermittent power.

I will tell you this: shutting off power to the fuel pump will cause your engine to quit RIGHT NOW. In a recent thread some folks were questioning the immediacy of a fuel pump shutoff over-rev protection. I don't. In a CIS car, shutting off the fuel pump acts JUST LIKE shutting off ignition. I mean, it is just as quick.

Back home now.

My best guess, based on the input I have received on this and other Pelican posts, is that it's a fuel problem. However, it is effected by the engine (hot & constant speed). Rlane mentioned that he had a similar problem and replacing the fuel pump fixed it. (side note: I wish I could make a buck everytime I thought I had a similar problem to someone else's problem.) Yet, the pump could be right on the edge of performing.

I'm trying to think this through because there are enough clues to figure this out, right?

What would cause the pump to stop performing when the engine is hot and driving at constant speed?

Oh, BD, New Zealand is a long way to deliver a beer, but I'd love to visit the place.

If you do come to NZ, use my house as a base and we'll go for a drive up country to the winemaking area :)

Car starts fine and runs fine at first.

Once warm, constant speed triggers engine shudder.

Once engine begins shudder, it doesn't stop until it idles or is off for about 10 minutes

Looking back on what you stated it may be a fuel problem. When the engine is cold, the pressure regulator reduces pressure on the air flow sensor plate to allow more fuel to enter the fuel distributor (maybe why car starts fine at first).

As the engine warms up, the pressure regulator restricts flow to increase pressure on the air flow sensor (reduces fuel flow - less sensitive).

When you shut the engine down, it takes about 20 minutes for the pressure to drop in the fuel distributor and the pressure regulator is cooling down also.

It's possible that the return line to your fuel tank from the fuel distributor could be causing the problem. It allows excess fuel through the relief valve back to the fuel tank. If it can't return then the pressure in the system will rise.

Get a fuel pressure test kit and check your fuel pressures. That would be a good starting point to ensure everything is working right with the fuel system.

Steve

I'd agree that a weak fuel pump could act this way. Electric motors areless efficient when they're hot. But the fuel pump is going to be the same temperature as the fuel, so forget that. Electric fuel pumps are gasoline-cooled, believe it or not.

I'm still betting that six pack of Heinken that there's an obstruction in the fuel distribution system. And the first place to look, really, is at the last gallon of gas/crud that drains out of the tank. Rinse the fuel pump and blow out the hoses, especially the one going from the fuel pump to the engine compartment. And the other lines there while you're at it and a new fuel filter. I think you'll know it when you see it. Bright orange gasoline and chunks of rust.

The fuel pump was replaced and the problem persists!

Suppose now need to check the fuel lines, the spark plug wires, and the catalytic converter.

Thanks for support. Hopefully the problem will be resolved soon.

I have had the same problem on my 914 (D-Jet). It is more difficult to "hear " the fuel pump in my SC so it may be difficult for you to experience the same results....I can hear my fuel pump "moan" (rhythmically) when the problem occurs. I took a piece of hose and attached it to the cold start valve and on the other end I mounted a pressure gauge. I could watch the gauge go up and down when the problem occurred from ~30+ psi to ~18-20 PSI. I still can't figure out why this happens... but it seems to be pressure related and intermittant.... usually at highway speeds. Soooo...this leads to the question... what is your fuel pressure? and could this be related to the pressure regulator? Brian

The car screams from 0-120mph and down and up, but go constant speed for a few minutes and it's sick. Acts like it's out of gas and stays that way until it idles for about 10 minutes or is turned off for about 10 minutes. Then it's back to... go to beginning of this reply. Time for a beer! or two!

Hey, I can still wash it. At least I know how to do that.

My 3.2l had symptoms similar to BKOMAR. My fuel pump would wail and the car would start to shudder. I did the fuel pump into a bottle test and saw very anemic output. I thought new fuel pump time, but when I took the pump out the line from the tank to the pump hardly leaked at all. It turned out the line from the tank was pinched and got squeezed off when it warmed up and became soft . Repositioning of the line completely cured the problem. I had anticipated finding Superman's rust blocking the feedline.

best Mark