Hi all, I've had to admit that I need some advice/guidance.

Bear with me as I need some advice;

My girlfriend owns a 1997 Escort 1.8 GTI, the car was owned from new by my brother-in-law and has always been serviced by me, always well ahead of shedule oil every 3 k, now every 5k, formerly it was changed using Mobil/Castrol 0w/40, now it gets Magnatec 5w/30 and the last change was Valvoline 5w/30 (there is a reason for telling this)

So,the running problems. It was cutting out at junctions etc, so a new idle control valve cured that as cleaning the old one didn't help. Then it wouldn't start one day, I tried everything, in the end, I towed it home as I was going away for a week, we came back and guess????? - yes, it started and ran no problem for about 2 weeks, than the same again, this happened a few times until luckily I was in the car and had tools. We had driven around 5 miles, went for a walk- 30mins, then came back and it wouldn't start, same as always spinning over fine, but not a hint of firing. It was getting a spark at all leads, fuel at the shrader valve, compression sounded fine and no red flashing light on the dash of the immobilser. I checked fuses, relays etc, I went to wash my hands and when I came back, yes- it stared!!! Grrr.

So, the next time this happened it was the same, girlfriend had went shopping, came out wouldn't start, I tried to get it to go but it wouldn't, so we left it and went back later but still wouldn't start, as before, getting fuel at rail and I could hear the pump, getting spark and compression sounded fine. After alot of fiddling, checking I fitted a spare MAF I had and it started although very rough, mis-firing and black smoke- unburnt fuel out of the exhaust, so we got it home and left it.

After 2 mates' diagnostic kit wouln't reaad the codes (think its OBD1 and most readers are OBD2) I got hold of another mate who had the right reader. It showed up saying MAF and TPS were at fault, but he checked the voltage to the MAF and it was less than 12 volts (running), according to specs the MAF runs at 11-14 volts, so if it is getting under 12 (11 odds) when running then we guessed that when cranking it would be much less and cause the non-start. I drove it to his workshop (mis-firing, black smoke, cat getting really hot) and stopped it, I needed to move it and it wouldn't start, he took a 12v feed straight from the battery to the MAF and it started- problem found! But it seems the MAF I'd swapped in was faulty also it's output voltage was wrong, so it was back to the original MAF.

After a very late(early) night, he traced the wiring back and it comes from the main power relay in the fuse box (purple wire) and feeds out to the MAF, TPS, injectors and speed sensor at the gearbox.
To resolve this he put in an external feed to the relay, by-passing the faulty feed to the relay in the fusebox, a temporay fix, but it always starts now (last 2 weeks)

Now, what it does now is,it starts fine, it'll idle fine, then after a random amount of time the revs will drop and the engine labours, it never stalls though, a quick rev and the idle settles again for a random time. Also if you rev the engine at the throttle, the engine hesitates a bit mid-range as it revs up, obviously some hesitation or mis-fire as the engine rocks on it's mounts. When driving, part throttle or even 3/4 throttle is fine, but full throttle and it holds back, makes alot of induction noise (pipercross fitted) but doesn't go any faster, it doesn't feel like an ignition fault, more like fuel holding back. It does feel down on power too.

So far I have changed;

Plugs, leads, coil, Lambda, crank sensor, cam phase sensor, swapped TPS.

I have also done a compression test, all were about 100psi (low I thought, but it was a cheapo tester).

Today I removed the exhaust and cat for inspection, the cat is fine, not broken up at all, I fed the airline through it and there was plenty of flow, not the cat then. I also dropped the fuel tank to check the pickup strainer, again- fine, a little dirt on it but to be expected. The pump isn't noisey and sounds smooth.

Now, I'm almost out of ideas, a new fusebox? I read that the mk6 boxes were "bar" type and meant to be better, but I've only ever changed mk5 boxes.
Or sticking valves? The car has 110k miles on it and does get good regular oil changes with the correct oil grade, but it has had a diet of supermarket fuel for the last few years.

All replies and advice welcome,

Cheers

 

Any ideas here?

 

Still having trouble with this.
I have fitted a new coolant temp sensor as it is worse when cold.
I checked the fuel pressure, at idle with vacuum - 2.3 Bar, then no vacuum -2.9 bar, so seems fuel pressure is ok.

So I'm down to fuse box or sticking valves I think,

Any further suggestions?

 

Have you tried a new lambda sensor in the exhaust ?

Scott

 

Yeah, as above. I changed the coolant temp sesnor at the weekend too.

 

hi
did you ever find the fault with your car?
i've got a 1.8 16v ghia 105bhp that is giving me exactly the same problems, and i'm running out of things to replace and run out of patience with it,