Author Topic: wont start......wierd problem?  (Read 3247 times)

Offline olly s

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wont start......wierd problem?
« on: September 02, 2018, 10:22:28 pm »
I'm nearing the end of reshelling my GT/G40 into a 1.3 genesis breadvan. I put the engine in/wired it up last weekend (all bar fuel pump as front was in the air and rear was on the wheels) it started and revved up fine on Monday. Tuesday I put a clutch cable on and took the front end off the axle stands and it refused to start from there  ::)

After spending the day looking around it today with help from my friend (another g40 owner) we came to the conclusion that there is no spark and the pumps not priming. We assumed that either a relay was dead or the hall sensor, tried both the relays from his car and still nothing. Tested the hall sensor by manually winding it over to see if it did the priming injectors etc thing and nothing, even with a random distributor i had lying around nothing would happen.

After a phonecall with Kiz and a bit more looking around it seems theres no ignition live going to the relays although the permanent 12v is there, does this sound right?

Is there anything obvious I could have missed/knocked off or is it now a guessing game looking through everything possible in the whole loom?

Appreciate any help i can get thanks  8)

Offline NealPeal

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Re: wont start......wierd problem?
« Reply #1 on: September 03, 2018, 08:40:29 am »
[edited!]
Just a thought.. at the moment i can disable mine by just fiddling with those relays and wires even with new relays in.. crunchy wiring suspected but bending fixes it..

Dunno how brave or desperate you've got but i know sticking 12v  on the lambda-heater +ve feed bypasses the ecu fuel relay control. Then 12v on the dizzy +ve, That all spins the pumps and should spark if the ecu is listening...

It was immobiliser experiences got me and Matt to find that out last week wondering why the heater was cold etc, mine only disables the starter his does this relay
..
I only say the lambda heater because we were playing with it at the time, use the relay socket itself if you can but bear in mind switching the engine off off might involve pulling the wire out again....

*Use an appropriate fuse* on the bit of test wire you use, it's only to try to get things spinning but always wise (but I often never do!). I'd use a 10ish Amp, and keep it *safe*… Once you see a spark you're there probably...
Cool
Neal

« Last Edit: September 03, 2018, 09:50:57 am by NealPeal »

Offline G40supercharged

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Re: wont start......wierd problem?
« Reply #2 on: September 03, 2018, 08:52:08 am »
The fuel pumps should run for a couple of seconds when you first turn on the ignition; engine doesn't need to be turning over. Does sound like its just a problem with the ignition switch or wiring from it. One relay powers the ECU and will switch with the ignition (should always be on). The other one runs the fuel pumps and is driven by the ECU. When the engine is not turning this relay will not be switched on. The ECU uses the signal from the hall sender to keep the relay switched and so fuel pumps running. This is a safety feature if you crash the car and break the fuel lines so you don't get petrol sprayed everywhere.

Offline G40supercharged

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Re: wont start......wierd problem?
« Reply #3 on: September 03, 2018, 08:56:32 am »
Also check engine earths. I had an issue where the ECU earth was dodgy and the car completely died. I think one is through the mountings of the coil pack. On my car the washer bottle had leaked and corroded the coil bolts. Cleaning that up seemed to fix the problem (after changing ECU, dizzy and just about everything else - luckily I had two G40s at the time so could swap everything over bit by bit).

Offline NealPeal

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Re: wont start......wierd problem?
« Reply #4 on: September 03, 2018, 09:13:37 am »
"Yeah spinning the dizzy", number one diagnostic tool... Clicking injectors, pump noise, BINGO!!!!!
One step at a time it'll get there, lets face it it's a "points and carb" emulator, just watch the coil lead don't crack you one I've done before!
Cool

Offline olly s

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Re: wont start......wierd problem?
« Reply #5 on: September 03, 2018, 10:49:44 am »
The fuel pumps should run for a couple of seconds when you first turn on the ignition; engine doesn't need to be turning over. Does sound like its just a problem with the ignition switch or wiring from it. One relay powers the ECU and will switch with the ignition (should always be on). The other one runs the fuel pumps and is driven by the ECU. When the engine is not turning this relay will not be switched on. The ECU uses the signal from the hall sender to keep the relay switched and so fuel pumps running. This is a safety feature if you crash the car and break the fuel lines so you don't get petrol sprayed everywhere.

I'm thinking ignition switch or wiring myself too, iv never changed an ignition though I assume it's a ballache 😂

Luckily the car the conversion came from is still on my drive so can steal bits from it. Just finding which bits to steal is the hard part, will go through all earth's today aswell to be sure.

Offline NealPeal

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Re: wont start......wierd problem?
« Reply #6 on: September 03, 2018, 02:05:48 pm »
Just checking, the ignition lights come on and the car spins on the starter is what I think I've read..

If not, a quick test to check the ignition switch wiring might help like this.. Pin 3 on the dizzy (the white middle-thickness white one) is one destination of the actual ignition wire from the key... Stick a paper clip (we found ideal) down it and see if there's 12v there... If not stick 12v there it goes no-where else but the key... As soon as you do the fuel-relay timer should make a noise if it is that would be ideal sort of thing..
Mine was dropping to 6v starting when it was playing up, immobiliser wired up with 20w speaker wire unrelatedly!!
It'll go soon as you find that one thing, don't lose heart it's fun!
NEAL
« Last Edit: September 03, 2018, 02:19:23 pm by NealPeal »

Offline olly s

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Re: wont start......wierd problem?
« Reply #7 on: September 04, 2018, 04:04:34 pm »
Have now had it running by pikeying a 12v to the 5 pin relay where the ignition switch should send 12v to.

I just don't know where the ignition switch is to Nick off my other shell 😂