Help from a genius required.

So - around 12 months ago i bought one of my teenage dream cars - this promptly turned into a nightmare - in the last 12 months i have been able to cover 200 miles in the car and have spent nearly £1500 on it :-(

My own fault - in my excitement at finding an 86' Gti Cab i drove it briefly when it was warm - bit the guys hand off and walked away - knowing some "mild restoration was in store" and that was fine for me.

The next day - the car wouldn't start from warm, over a few days it got so it wouldn't start at all - i'd bought a pup :-(

Took it to a Garage who advised it was very low on compression - ok - lets rebuild the motor, had to save up for that so it was some months before it got done - eventually got the funds and got it into them.

5 Weeks later i get it back from the Garage - started first turn of the key and drove ok, running a little warm (But we do have 40 degree summers) other than that ok.

The very next day it cut out when warm and wouldn't start, this problem persisted for a week or two, adjusted the idle higher still and it stopped cutting out - knowing this was a temporary fix.

Then after a 15 mile drive one day it stalled at the lights and refused to start, i got it towed back to my workshop (I'm a car audio fitter) and struggled with it for several weeks - dizzy cap and rotor had been changed when i bought it, along with plugs, alt belt, leads, rotor arm.

I ordered a new coil - changed the wiring as it was old and worn - no difference, changed the ignition switch - no difference.

Then a customer suggested removing the fuel pump relay - removed it and it fired and died! First sign of life from her in two months.

I then disconnected the lift pump and the car started and ran with the fuel pump relay in but the lift pump disconnected! - Idle still high - if adjusted properly it would cut out - it now ran for two weeks.

Then one day driving back from work it died again and refused to start - towed back to workshop again.

Up until yesterday we had no firing at all, then it fired a few times over an afternoon but was misfiring heavily - if throttle pressed it would die, we checked the plugs etc - intermittent spark on 2nd cylinder, removed, cleaned and refitted dizzy and plugs, checked coil etc as per haynes manual, reset timing correctly from guide on here, now good spark but it isn't firing at all.  :dontknow:

I'm going to remove the injectors tonight but the plugs are wet so i don't see how it could be fuel, sadly i can't put it into a garage - no one over here will work on it  

Ideas on what i should be testing next?

Injector test done - all four are non conical (Jetting slightly) but ironically flow rate on all four in the bottle test is identical.

One strange thing - the test states:

The fuel pump may prime, the injectors may
chatter and a small amount of fuel may flow,
but should then stop.

The injectors did not chatter and no fuel flowed when the switch was turned on (Until plate was raised) HOWEVER - the fuel pump never stopped priming? (I'm assuming thats the electrical whirring noise?)

As I understand it, it's the relay that affects whether the pump primes - there're 2 types, 1 that primes, 1 that doesn't.

If you removed the relay, and wired across its contact points on the fusebox to test the injectors, the main pump will continue to run all the time the ignition's on.

So that's nothing to worry about.

What's your position with the lift pump? Still disconnected? Replacement pumps are available on ebay cheaply to fit to your sender unit.

Without the lift pump, the main pump is run harder, drawing more amps, which leads to the relay getting hot when the car is running, then the plastic of the fusebox melts, and the connection to the relay is lost.

With the pumps both connected, the relay installed, and the ignition on (in the "run" position) you should hear the pumps running.

If you have a spark (at the right time) and air, all that's left is fuel! (unless there's something silly like a failed head or inlet gasket, dropped valve etc)

The performance of the engine may not be optimal with the slight jetting from the injectors you describe - but it should run!

Lift pump was reconnected, pumps run when the ignition is on.

The only component i haven't touched is the metering head. Hmmm

I hope its not a failed gasket - only just had the damn thing rebuilt :-(

Would an air leak on the hoses cause it? They look kinda rough?

Whats puzzling is it was driving home fine and suddenly died!

Bear in mind I'm no expert - just chucking ideas around, as nobody else has been on to you!

I did also wonder about an air leak - It'd have to be a big 'un though!

After all this trouble, it's worth removing them 1 by 1 and checking them.

Are your injectors air shrouded? I had issues with the plastic injector seats breaking up, making an air leak INSIDE the engine… You can test for that by blanking the air shroud feed (in the back of the head, near the injector holes)

Sure you've checked, but the cambelt's not skipped a tooth? (pointing your timing strobe at the cam and crank should tell you)

The only reason I'd think for the metering head suddenly failing is a clog - and as you're getting fuel to your injectors, I'd think that unlikely.  

Have you had the 5th injector out? I suppose if it's failed and is leaking it could be flooding - therefore reducing pressure to the other injectors…?

fonzooorooo said

Are your injectors air shrouded? I had issues with the plastic injector seats breaking up, making an air leak INSIDE the engine… You can test for that by blanking the air shroud feed (in the back of the head, near the injector holes)

Sure you've checked, but the cambelt's not skipped a tooth? (pointing your timing strobe at the cam and crank should tell you)

Have you had the 5th injector out? I suppose if it's failed and is leaking it could be flooding - therefore reducing pressure to the other injectors…?

Air shrouded - ok you lost me….

Belts new - and not skipped - cam timing checked - its perfect

5th Injector - tried with it disconnected to make sure :-(

Are there "top hats" on the tips of the injectors? and an air hose going to the back of the cylinder head, near the injectors on cyl. 3&4?

I'm suggesting physically removing the 5th injector, and checking it's not leaking when the engine's (trying to) run… Disconnecting it electrically won't confirm whether it's leaking.. The pressure remains in the fuel line behind the injector all the time.

fonzooorooo said

Are there "top hats" on the tips of the injectors? and an air hose going to the back of the cylinder head, near the injectors on cyl. 3&4?

I'm suggesting physically removing the 5th injector, and checking it's not leaking when the engine's (trying to) run… Disconnecting it electrically won't confirm whether it's leaking.. The pressure remains in the fuel line behind the injector all the time.

Air hose secure - will remove injector and check

Try removin the small breather pipe to the distributor that runs to the servo pipe and blockin the holes, we done it to mine and the tick over is alot calmer! X

i wonder if the relay is faulty or there is fusebox damage. on my gti sometimes only 1 of the fuel pumps worked (assume due to not enough current to run both) eventually i traced this to a completly melted fuel pump fuse socket. this may be why disconnecting the lifter pump helps on yours.

check the fusebox carefully for damage, in particular look for corrosion at all the sockets on the back and around the relays, plus look for heat damage around all the fuses the fuel pump one in particular.

for short term testing remove the fuel pump relay and drop in a #17 or 18, this will make the fuel pumps always run with the ignition. this will rule out wiring problems and also a faulty fuel pump relay. note that it wont be safe in a crash! the factory fuel pump relay uses a signal from the rev counter so it will only work while the engine is running. it sounds like someone may have already bodged the relay if it currently always works with the ignition on, if its a #53 or std switched relay then thats why. the 53 is similar to an 18 but the terminals on it are too small so dont make good contact in the fuel pump relay socket.

try pulling the plug off the 5th injector for now, see if that makes any difference. if it does maybe its stuck open or there is a problem with the 5th injector thermoswitch. this is the large 2 pin brown one in the front flange.

i would also remove the lifter pump unit and have a good look inside the tank for crud