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ENGINE/FUEL PUMP QUESTION

Posted: Wed Mar 13, 2013 5:57 pm
by Melv
Hi I'm new here but I really need some help.........

My friends just bought a 1984 CL (theres a couple of posts from the previous owner on here) I know its a rare car and he's asked me get it running right for him.
The car has the pieburg auto choke carb which we'll change in due course but it although it still has its original pump in place it has an electric facet fuel pump as well? There is a filter too but NO fuel pressure regulator?
Won't the electric pump just run continuosly and over fill the float bowl? How easy is it retrofit an original mechanical fuel pump?
And on the way home the car broke down with the following symptoms...

1. Slight misfire followed by
2. Increasingly poor running.
3. Car stops
4. After a short period car will start and rev fine at a standstill.
5. Car runs well for 100 yards, but quickly gets worse and stops again but starts ok still.

I've had a gander at some posts and my suspisions are the ignition module failing once it gets warm, is there anyway to test it? Whats the best way to test a coil? do I need to measure the reistance to rule it out?

The previous posted on the fault but never mentioned it to us when we collected the car! Most other things seem ok though.

Thanks for any help already nice fourm. :nerner:

Re: ENGINE/FUEL PUMP QUESTION

Posted: Wed Mar 13, 2013 7:03 pm
by mark1gls
Also worth looking at the fuel filler neck as its under the rear wheel arch and prone to rusting, look inside the filler neck for holes, dirt/water gets into the fuel system and causes alsort of problems.

Re: ENGINE/FUEL PUMP QUESTION

Posted: Wed Mar 13, 2013 10:16 pm
by Melv
The filler neck is rusty and will need changing in the future, but, its not enough for me to suspect its the problem. The car has a clear fuel filter fitted which looks pretty clean and the fuel in it appears clean too.
However the ignition module appears to be an original VW/audi unit and an old one at that so We've got on order from our local motor factors. What also makes me suspisious is I was originally told that they start to fail as they warm up.......Earlier on car misbehaving and cutting out. Later (8pm -2 C ) and its running fine and pulling like it should. The coil also looks pretty old so I'm keen on swapping that too.
The car was only £350 has MOT TAX and no structural rust whatsoever just the usual age/paint related blemishes so we expected problems. I was thinking worn suspension poor brakes bad steering feel dodgy electrics leaky doors but its all pretty good.

Re: ENGINE/FUEL PUMP QUESTION

Posted: Wed Mar 13, 2013 10:33 pm
by Tim_R
Sounds like someone has fitted an electric pump to try and cure the problem, if the filler neck is rusty, pull the fuel gauge sender out the tank and check the fuel pickup filter on there. My money is on that being blocked and causing fuel starvation issues.
Even the standard mechanical pump will be able to supply more than the engine will use so as long as the swirl pot and return line are still fitted the electric pump shouldn't be a problem, if it's a low pressure one for carbs.
I've not seen or heard of ignition amps giving too much trouble on these cars over the years, not saying yours isn't dodgy for sure but I'd look at the fuel pickup in the tank first. (I've got through 2 ignition amps on my pug in the 5 years I've had it)