A tale of 2 GTIs

[Whaleshark]

Sadly my trusty '89 8V passed away(prohibitive to fix for MOT) last month.

Was rather gutted as it had lasted me 75,000 miles(3 years) without so much as an oil change.  Infact when it failed the MOT there was nothing wrong with the engine(low emissions too) and I was still averaging around 38mpg a tank - worked out through odomotor and pump readings, not MFA.

The second Golf is a newer model, a '90 8V !   I picked it up for a reasonable price, but knew there was several things wrong with it. 

The main one is that it lacks power.  I adjusted the timing and checked obvious things but couldn't find much improvement.  I had resigned myself to wasting a few days to try and sort the problem, albeit sometime in the near future when I am not working quite so hard.

Now here is where it gets strange.  A few days ago, the power returned and it was like I was back in the '89 again.  It was like the proverbial off a shovel for the rest of the day and the beginning of the next, where upon the power disappeared and it was like driving a 1.3 again.

I am baffled as to what this could be.  Something electrical perhaps?  I really have no idea, but am hoping one of you might.

Cheers, Ed

[Jay]

bad ECU?  You still have the ECU from the '89 ?

[jezza16v]

75k without an oil change  , you're a cruel and heartless bas**rd........

It might be a knackered knock sensor retarding the timing.......they tend to split and fall apart and the wiring shreds, much more expensive than an oil change though.......?  Inermittent vac leak?

[Wayne]

75k without an oil change, was there any left in the sump.

[l333]

hi ive had similar probs before turned out to be exhaust blockage

[DarnPB]

It sounds like an intermittent sensor to me, or as someone else said, the ecu. You have another car full of spares, so start swapping one thing at a time. Also look at the vacuum tubes for a split.

Then give it an oil change.

[Whaleshark]

75k without an oil change  , you're a cruel and heartless bas**rd........

It might be a knackered knock sensor retarding the timing.......they tend to split and fall apart and the wiring shreds, much more expensive than an oil change though.......?  Inermittent vac leak?

I know, I know.  It started off as something I just never got around to and I never expected it('89) to last beyond it's first MOT so there seemed little point. 
Then it became a cross between fascination and superstition.  I felt that if I changed the oil, then it would surely die the very next day. 
It did have fresh oil going in every so often - probably around 1l every 8,000 miles - not a huge burn I understand, certainly well within VWs limits. 
I think that it is a testament to VWs engineering and modern Oils.  As I mentioned before, on it's final MOT, the hydrocarbon readings were still really low. 
Infact the only problem that I ever had with the engine was when the ECU once failed.

That brings me on to the other('90).  Funnily enough last night driving to see the missus, it was particularly gutless, with a bit of a stutter.  However, this morning it was back to full power for only the 2nd time in the month or so that I've had it.
I think the ECU is the first thing that I'll try.  When the ECU failed before(in the '89), it really failed.  I couldn't even get a spark.  So the ECU is already out of the Gti I had before('88)!  The vacuum tubes I have already checked and I don't know where the intermittent and knock sensors are.  If I get a chance I will try the swap today or tomorrow and report back.

Also, I promise to change the oil a bit more regularly.   

[jezza16v]

1 litre of oil per 8000mls. ..800 is probably more normal for one of these......I want that engine. .......why not just drop it into the '90 model and be done with it?

[Organisys]

Check all the eraths first, including the fuel pump.

[Whaleshark]

1 litre of oil per 8000mls. ..800 is probably more normal for one of these......I want that engine. .......why not just drop it into the '90 model and be done with it?

You made me think, and I've just realised I made a mistake with my maths.  75,000 miles has taken me 3 cans of oil(not 2 as i originally thought)  75,000/15 = 5000miles/litre.  A lot of motorway miles though, which I don't need to do any more.

I have often thought about dropping one engine in t'other and if ('90) dies I might take the plunge.  Otherwise, I find the idea a bit intimidating.

Cheers, Ed

ps.  Organysis - Will have a search around for earths.  presumably fuel pump earth is one of the terminals of the connector that plugs into the pump/filter unit under the car?