IT'S FIXED!!!!!!!!!!!!!!!!!!!!!

OK Guys,

I think I have solved the running problems i had with the car.
This evening I swapped the metering head over for a spare Corrado 16v one that my mate had lying around. WHEN i can get it started it seems to rev fine now, the miss has gone, though the fuse for the fuel pump is blowing after about 10 seconds meaning it is cutting out again.

I have the fuel pump on a switched circuit and I added a 15Amp fuse. Is this too low? is there a fuse in the standard set up? If so, what value?

Also, when i turn the ignition on and try to start the car, it wont go until I turn the pump off, then switch it back on again when it fires!?!?!
Any ideas? too rich a mixture perhaps? (corroado 16v is a 2.0L isn't it - probably set for a higher fuel delivery).

Any ideas appreciated!

Cheers,
AL.

Mmmm - don't see why the fuse will start blowing just cos you've swapped the metering head :? - unless it is has a higher system pressure requiring more power from the pump.  I think the original is 15A - though not sure.

Probably is too rich - try starting with the Cold Start Injector disconnected.

crazyquiff said

unless it is has a higher system pressure requiring more power from the pump.

That is what I thought.

If the new metering head requires more flow, then the pump will be able to spin faster due to less flow resistance. This also means it would require more power from the battery, hence the current draw increases blowing the fuse… If I up the fuse to a 30Amp, would this still blow before the pump melts if the current got too much?

I think it is more a case of pressure which is making the pump work harder to maintain.  I'd up it to 20A first and see what happens - 30A is a lot of power to be running through those wires  8O

That is my concern…

I was just reading a link in another post that says the current draw on a fuel pump should be betweem 5 and 8 amps. If this is the case, then i certainly don't want to exceed 15Amps on the fuse as something is obviously not right!

Well, I swapped the old metering head back on to the car last night and it has cured the blowing fuse - Obviously something to do with the amount of work the pump had to do!

Bad news is that it is still missing on the old metering unit. I tried to take it apart to clean/look at it, though even with all of the bolts that hold the block together out, I could not seperate the two parts?!?! I didn't want to go at a precision unit with a hammer, so I whacked it all back together  :dontknow:

whats yours doing missing a beat when there is load on the engine or just idleing? coz i've got it when the engines under load i've got a 1800 fuel dizzy on my 1.6 shouldn't make any diff i dont think?

Well, I have now changed the Metering head for another 1.8 gti version……


…And it is still missing!!!!!!!!!!    

Really starting to waz me off now. I don't know where to go next.
Going to do a compression test to rule out head gasket, though I don't think this is the problem. Also going to get some jam jars and do the flow test that was in one of the other threads.
One question on this though, Do you do the test with the flap lifted fully?
I'm off to read through it again.

AL.

AL_Mk1 said

corroado 16v is a 2.0L isn't it - probably set for a higher fuel delivery
Any ideas appreciated!
Cheers,
AL.

Depends which car it's off AL. Early Rado's were 1.8 16v's. Also the metering head has a warm up reg type attachement on the side on the 2ltr 16v which has a plug coming off it. So if you have a metering head with this type of attachment I reckon it will give you fuelling probs, as when they ain;t working it makes it run like its under fuelling on cold start. Bro has just had a problem with his 2ltr 16v and it was wheezy and missing when cold.

Al - assume this is the same problem as on Phill's thread? When you say missing, do you mean failing to fire on all cylinders? Is this on idle, under load, all the time? Have you tried pulling HT leads one by one with engine running to identify the missing cylinder?

Cheers

markwon said

Al - assume this is the same problem as on Phill's thread? When you say missing, do you mean failing to fire on all cylinders? Is this on idle, under load, all the time? Have you tried pulling HT leads one by one with engine running to identify the missing cylinder?

Cheers

It is as if it is missing on one cylinder most of the time (Idle/ low revs/ high revs) but mostly under acceleration…

I pulled one lead with the engine runnig and it hurt so I didn't pull the others…. I shall try this tonight I think. At lease if I can narrow it down to one cylinder, I can swap the plug and lead to see if it is something as simple as that, though I would have to be pretty unlucky as both plugs and leads have been replaced to try and eliminate these items!

What fuel system are you running?  K-Jet or Digijet?

It might be blocked injectors?  That could explain why a higher pressure regulator solves the problem (pushing more fuel through so if the injectors are blocked, the nett amount of fuel is what it ought to be).

I pulled one lead with the engine runnig and it hurt so I didn't pull the others

  don't pull with your hands, use an isolated tool - I use plastic brake pipe cutters. Pull off the HTs with engine off and loosely refit on each spark plug (don't push fully on). You should then able to lift each one on and off its plug with engine running and without any pain.

Cheers

markwon said

Pull off the HTs with engine off and loosely refit on each spark plug (don't push fully on). You should then able to lift each one on and off its plug with engine running and without any pain.

Doh - That's a good Idea!

I would have thought I was intelligent enough to have though of that myself! ops:

...have to admit I copied off a mechanic I used to use.

i must admit I learnt that the hard way.. it's amazing the amount of shock you get from one of those!  8O

OK - Popped home lunchtime and have sorted out 4 large jars of the same size to do this flow test tonight!

Will also pull the leads one by one to see if I can identify a particular cylinder at fault.
Better do this bit first incase any spark finds stray fuel vapour eh!

AL_Mk1 said

Better do this bit first incase any spark finds stray fuel vapour eh!

I would, could get messy otherwise   for you and the car!

I seem to have developed the same symptoms as AL on my White Cab!

Engine seems to be missing at all rev ranges - on using colour tune the cylinders are firing at what seems an Ok mixture???

If I pull off leads in turn the revs drop off slightly but not dramatiaclly.

Timing is bang on as is cam timing - compressions are OK.

Dodgy Hall sender perhaps guys ? Think this gives the same as a misfire if they start to break down.

God knows how you test one though……..