Hi guys, first time poster... long time reader. great site, lots of great build stories and tech info.

So here's the thing. My car suffers from what i'd describe as heat soak. It starts fine when cold, but when trying to restart it hot - after it has been sitting for say 15 mins - 2 hours it has no injector pulse and spark. This has been verifyied using a timing light.

If i crank the car over say 4 times then release the key (engine not started) then retry and start it, it fires straight up.

The things i have changed to isolate the problem are:

New Bosch Dizzy, cap and rotor
New coil.
New leads
Second hand ecu's - one from a gli falcon, and one from a NL Fairlane.
Second hand ignition switch.
Re-earthed the ecu using all the earthing wires from the ecu and regrounded to the body.

The car is dead stock and NOT on LPG.

So what's left? The BCM perhaps? Relays?

I'm stumped and would love to hear your feedback, especially if you've suffered the same problem.

Thanks guys,

one man.

Bump...
seems like I'm the only one with this problem..

Any suggestions lads?

Hello,

It could be a relay, you could try and swap it with another and see if that helps. They are a sort of " standard " item and should be in sockets. Look for corrosion on the terminals when you take it out.

I'd be leaning towards BEM, or Smartlock fault. Certainly a strange one!

Thanks Ghia97 & 96ELGli,

I believe the smartlock has been disabled, as the light does not flash on the dash...
So... The BEM could be the culprit.
I shall investigate further.
I've just found this document and hope this helps solve the hot start bug bear..
documents.php?d=49

Thanks again lads. This has me stumped..

Hi guys, well it's bin a while since my last post..

Ok, here's what I know..

I purchased another body control module and still no change in the hot start issue.

What I HAVE noticed is that when turning the key to the "on" position when hot the fuel pump fails to prime..
So maybe the fuel pump (or relay) is dieing a slow death perhaps?

Any takers?

All input is good input.

Does it do it on hot days or when you leave the car out in the sun or every time you drive it?

I'd be looking at ECU or as you say fuel pump relays or the pump itself.

I've had a few E series with dry solder joins on the ECU causing these issues, car starts fine in morning, in the middle of the day when its warm, wont start.

I'd be trying the obvious first: Fuel pump, relay, etc. Then I would start tracing through the wiring to see if there are any breaks/corrosion.

Maybe try replacing ignition switch?

I had a problem with headlight wiring once. There was a break in the wire, inside the insulation, and when it got warm, the break opened up and the headlights went out

Hi guys, thanks for your speedy replies.
I HAVE changed the ignition switch, and that made no difference.

The car does this hot start thing regardless of the weather conditions. If it's winter, summer, autum or spring... and left for 15+ minutes it will still suffer from the "hot start issue".

Update:

So.. I have checked the fuel pump relay connections and they were like brand new. No corrosion, no suspect connections.

So all i can do is bite the bullet and swap out the fuel pump.. neva done one, but after doing some reading it sounds like a bee icth of a thing.. the locking ring that is...

Will keep you posted as to what happens after I change the fuel pump.

Thanks again guys.

One Man

IIRC i simply took a hammer and pin punch to the ring, but that was a while ago now................

1. Use a screw driver to pry off the ring clamp on the fuel pump lid. Either you gotta drop whe whole tank (remove bumper, undo 2 bolts holding the fuel tank), or just do everything while the tank is in the car. Doing it with the fuel tank is out is much easier but if ur fuel tank is full you need to be able to bench 70+ kgs to lift it back up.

2. With the ring clamp out, use a tool that clamps onto the locking ring. You can grab that tool for 15 bux from supercheap or repco I forgot which one. I have one and it does me favours every time. Sit a size 18 or 19 nut and slide it open with a breaker bar.

I have the tool and extra spare rings if you need some I'm up I'm the northern suburbs in Melbourne. Just pm me.

Idk if the fuel pump is the actual problem. It would be dying if it gives a weak/dying sound when u prime it (key to ON position), and would be constantly humming in a high pitch tone when u listen to it closely, and would occasionally cut out, making the car shudder, lose power and slow down...

I would check all relays and test all wiring. Seems like a broken wire getting worse after warm-up. Could be the relay wiring to the fuel pump relay, or the actual wiring powering the fuel pump. One of them must be broken and is getting spaced out even further while warm up.

1. Use a screw driver to pry off the ring clamp on the fuel pump lid. Either you gotta drop whe whole tank (remove bumper, undo 2 bolts holding the fuel tank), or just do everything while the tank is in the car. Doing it with the fuel tank is out is much easier but if ur fuel tank is full you need to be able to bench 70+ kgs to lift it back up.

2. With the ring clamp out, use a tool that clamps onto the locking ring. You can grab that tool for 15 bux from supercheap or repco I forgot which one. I have one and it does me favours every time. Sit a size 18 or 19 nut and slide it open with a breaker bar. It's called a fuel pump removal tool

I have the tool and extra spare rings if you need some I'm up I'm the northern suburbs in Melbourne. Just pm me.

Idk if the fuel pump is the actual problem. It would be dying if it gives a weak/dying sound when u prime it (key to ON position), and would be constantly humming in a high pitch tone when u listen to it closely, and would occasionally cut out, making the car shudder, lose power and slow down...

I would check all relays and test all wiring. Seems like a broken wire getting worse after warm-up. Could be the relay wiring to the fuel pump relay, or the actual wiring powering the fuel pump. One of them must be broken and is getting spaced out even further while warm up.

Hello,

If you are still having this fault, I would get a cheap buzzer. For a couple of dollars connect it where the power to the pump is. You can hear it and know you have power. You have already replaced some parts with no fix, so a $2 buzzer is quick cheap and easy.

Remember Murphy's law ? If you buy a 2nd hand fuel pump you could replace it with a similar fault. You would then go through the process of replacing more parts, and be really annoyed at the end. I was looking for a front end rattle once, it couldn't be in the ball joints because they are new.......

The problem has now been fixed.

I went to the post office the otherday and when I returned to the car and tried to start it... nothing. Just cranked and cranked. I listened for the fuel pump, and it turns out it had failed.
It had stopped priming. Fitted a new pump, and everything is as it should be... hot starts, cold starts etc.

Seems the old pump was fine, be once hot it, wouldn't prime on the initial turn of the key. After cranking it briefly, then re-starting it, it would both prime and start.

I checked the old pump after i fitted the new one, and even smacking it while power was applied to it, it would budge. Just made a clicking noise.

So hope this helps someone, as it caused me grief for quite a few months...
On the bright side tho, I now have the following new parts that won't need replacing for a while:

Fuel pump
BCM
Distributor
Coil
Ignition switch
fuel pump relays

Thanks guys.