Author Topic: Turbo Conversion woes...  (Read 1547 times)

Offline DKnight

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Turbo Conversion woes...
« on: April 15, 2013, 08:26:21 pm »
So my caddy g40 turbo that has been hanging around at work for years i decided to complete.

its a mk1 golf caddy, with a g40 engine fitted, and then the turbo conversion bits.

I have the full g40 loom in, and g40 dash loom, and i fitted the full fuel system set up with lift pump and inline pump.

When it was a g40 with the charger it ran fine (many moons ago)

So i got all the bits on, fired it up and it ran but sounded like it had a slight miss fire. But not having that much knowledge of turbos it might have just been how they sound.

So it ran all fine, but as soon as i turn it off, it wont start again.
It did this for a while, and then just would not start at all and the plugs were wet with fuel (with the red injectors on)
It was as if they were over fuelling, ecu has the correct maf sensor to match the chip and injectors.

So tried to get it running but plugs were too wet and i gave up.

So then i have now swapped the injectors for standard, ecu for standard, and got new plugs.

Car fires up fine, but again gets to temp, turn it off. Wont start.
I dont know if it was just luck but when it would not start, i unplugged injector 2, turned over and it tried to start, so plugged back in and gave a bit of throttle and it started.

Ive tried all unplugging blue sensors, swapping ecu mid run, lambda unplugged but no change.

I just can not for the life of me figure out what is not right.

A few points to note, compression is fine, fuel pressure is fine but, when you turn off the fuel pressure drops to nothing quickly. Now i seem to recall they hold it in polo's, when turn over and run the pressure is fine tho.

The ignition timing when "correct" it is nearly all the way forwards (towards the car)
The idle is a right challenge and races and pulses sometimes, and idle screw is nearly all way out and it still seems to need more to idle right.

When up to temp and i unplug the blue sensor my previous g40's always seemed to cylce to 2k revs, but not on this, never.

Anyone got any ideas on what to check try? Im out of ideas now!

any help would be great



Offline hayesey

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Re: Turbo Conversion woes...
« Reply #1 on: April 16, 2013, 09:57:03 am »
to be honest the next thing I'd start doing is get a multimeter, haynes wiring diagram and start beeping out the engine wiring loom to make sure it's all OK.  As in, go through each pin on the ECU connector, look at the diagram to see where it should go and then use the continuity test mode (beep mode) on your multimeter to make sure the connection is good to whatever connector.

Then perhaps borrow an entire ECU and swap it over.  I had a weird running issue with my G40 years ago, spent ages with it and eventually borrowed an ECU as I had nothing else left to try.  Turned out that was it.  Andy S looked at my old ECU and said there's nothing obviously wrong with it but obviously something has blown on it.

Offline youngprodigys

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Re: Turbo Conversion woes...
« Reply #2 on: April 16, 2013, 07:37:56 pm »
are the3 vacuum pipes correct? and the fule lines connected to the fuel rail the correct way

Offline cheys03

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Re: Turbo Conversion woes...
« Reply #3 on: April 17, 2013, 09:18:35 pm »
Has the CO pot had any diagnostic attention? What's it's value and does it help if you try to lean the mixture by turning the adjuster anti-clockwise (iirc)?

Offline DKnight

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Re: Turbo Conversion woes...
« Reply #4 on: April 19, 2013, 02:39:03 pm »
well after a bit of fettling i am making progress, the inline fuel pump was leaking back through the pump, so not holding pressure. Swapped for another and it runs much better.

New plugs on and now it runs better, and when warm it starts again.

I checked the blue temp sensor plug and as i did one of the wires fell out, so that wont have helped and might be partly to blame for the car not starting.

going to get the multimeter out now and check a few bits.