Petrol from the Air Filter? (1988 8v)

[Mirage-]

Guys

Just digging for thoughts and suggestions really as my gti decided that it wasn't going to start again yesterday having driven fine before parking up.

Noticed a few things when checking what was wrong.

• Battery leaked, corroding live wire connection to the battery.
• Starter motor causes power to the ecu to be cut and the clocks reset when attempting to crank it
• A LOT of Fuel is being returned through the air filter.

I've replaced the battery with a new one but I'm unable to continue investigating until I get a replacement starter motor tonight as even shorting the terminals produces only a clicking sound.

I'm thinking that it can only be one of three things:-

The battery leaking and corroding the main live feeds to the car it may be that it's just tripping the ECU causing it to fire the injectors when the valves are closed.

One or more valves are stuck/burnt out causing a free flow of fuel with no spark to be pushed back up and out of the air filter when the pistons crank over.

The leaking battery has totally buggered my ECU.

Any more thoughts/suggestions?

Regards

Ian

[rubjonny]

Are you sure the battery is fully charged?  If so try putting the car in gear and rock it back and forth.  Perhaps something has siezed causing the starter motor to not be able to turn the engine over.

The fact that the ecu is cut and the clocks reset suggests that the batter lacks power, even with a knackered starter the clocks should continue working. Get a mate over and try jump starting it

[Mirage-]

Tried jump starting it last night with no luck so knowing the battery had been leaking decided it was time to get a new one.  New one fully charged and fitted, still cuts power when attempting to start.

It's hard to diagnose one problem when there are 4 more down the line before it Just when I thought things were starting to go right with a £590 FC insurance quote.

Will let you know later on about the starting problem after I replace the starter motor just wondered if there was anything else that could be causing fuel to be pushed back out of my air filter really.

Cheers

Ian

[Deefadog]

Can't help with the fuel, but i had exactly the sam prob when turning the ignition key, everything electrical, went off then back on.

I traced the problem to the ignition live power the stereo! it was touching the body work!  Worth a check as when you push your sereo in there it is very tight and those wires can get messed up!

Hope you fix it!

[Mirage-]

Thanks I'll have a look at the stereo wiring tonight as I did remove it some time last week to connect the dvd player, could have possibly caught some wiring when pushing it back in.


Ian

[rubjonny]

Hmm very strange!  Unless the motor is well and truely siezed and simply draining too much current?  You could try taking the motor out and jumping it direct from the battery to rule it out as the suspect.

The only other thing I can think of is either the ignition switch has gone, or possibly the cross over relay.  Although I'm not sure where it is or what exactly it does, something to do with cutting pwer to non-essential components when starting the car I think.

Edit: Oh and double check all your earths are on tight, especially the gearbox and rocker cover connections.  The gearbox lead is essential otherwise the ECU can get fried apparently   Only on digifant models though, KJet has no ECU.   I dunno what year digifant was introduced but I think 88 models have it anyway.

[Mirage-]

The wires were corroded on the old battery so it may have had a poor earth   

Fingers crossed I haven't blown my ECU  :embarassed:

Ian

[Mirage-]

Well last night I managed to get the replacement starter motor fitted and the engine cranking over with the starter.

But.....

Now there's no spark.  I've checked to see if there was a spark from each lead and then as none of them had a spark checked main lead from the coil, still no spark.

I'll have to have another go at it tonight and attack the lower voltage wires to the coil with a meter.

If there's no voltage going to the coil the only thing that I could think of was that the ECU is fried or a relay or fuse is knackered? Any advice appreciated.

Ian

[rubjonny]

You should still get a spark even if the ECU was dead, if the obvious checks don't work out it could be a problem with the hall sender or wiring.  The ECU only handles timing adjustments for engine speed/load etc.

[Mirage-]

What more could I test to narrow it down and rule a little more out.

I wasn't aware that there would be a spark if the ECU was buggered as I was under the impression it controlled spark and fuel.

Thanks in advance

Ian