GQ 4.2 Petrol Stalling After 20 sec

[Swerve]

Ok I bought a ebay special cheaply to use as a basher. Only had to install a bonnet.coil and radiator. Have done all that and now have a issue.

4.2 petrol with 400,000km, bloke said it ran rough before hand and is on gas.

I start her and she runs runs great for about 20 sec then seems to stall, I mean the tacho just go dead from say 3k rpm to 0 rpm, while the engine is dieing it sometimes starts back up as the crank is still turning. ?

My multimeter is away so cant do any testing but being carbie wit no fuel injection, my suspicion was electrial as no way petrol can cause it t die? my other thought was possibly a electrical short but watching the electrics they continue with no obvious drains when it happens, I checked the timing and thats all ok as well.

When I get my neter back I plan to first

1- Watch the coil voltage when this happens ? maybe teh gas system is causing the coil to loose 12v "+"ve somehow after 20 sec or, so, If this maintains 12 voly thinking of swapping the coil out ?

Any other ideas ? It also seems to have a electronic ignition also ?

Thanks

Steve

[Clanky]

Assuming we are talking operation on gas, sounds like the timing relay / engine rotation detector unit
This unit detects engine rotation after a set time ( in yourcase 20sec) if no rotation is detected then it will shut down the gas solenoids.
This is to stop gas flooding out after an engine stall or accident.
The 20 seconds is to allow gas to come through to get it started in the first place.

Sometimes this is integral to the fuel selector switch / gauge unit or can be separate

Cheap and easy to replace, but you need to find it first

[Swerve]

Sorry this is happening on Petrol.

I just collected my meter so hopefully this week I can watch the coil "+"ve voltage and check if this is being shutdown. I asume the coil voltage as it seems like teh ignition switch has been turned off, it happens so quick. This in my book, rules out fuel or carbie issues.

I know the LPG system has one petrol soleniod which is on, and I have also modifed for testing to turn permantly on. I may also temporay wire a new igniton circuit to isolate the gas system. I come from G60's which are simple If I temp wire the coil with a new 12v "+" and new earth fully isolatin existing wiring, supply 12v to teh fuel solonois, are there any other surprises on the GQ I should know about ? I could see some wiring going into teh carbie, But I asume this is choke related ?

[Clanky]

Have you checked the fuel cut (shutoff) solenoid on the carb?

Also, is there an alarm system installed ( or remnants of one) in the car? Might be the ignition cutout on this thinking it has been stolen

[maxtrax]

I had a mq on petrol/gas, it would run very ruff as the gas/fuel switch was running both. So I removed the fuel and away it went sweet! turns out to be the little box with gas tank level and gas on/off.

[maxtrax]

Also I have a old GQ tb42 engine complete sitting here if you need carby, or electrics.

[Swerve]

Yeah also does have a old alarm fitted, well siren at least.

Didnt think of the alarm, Now I have my meter back I can check teh coil power, Think I will rewire the coil for testing, providing she works then backtrack and remove the alarm Got a mate with the same model Maverick (This is a maverick as well) so I can always check his for stock wiring

But the more I think of it the alarm sounds very feasable !!! Just wish it wasnt bloody cold outside and dark. Arghhhhhh

[UKGQ]

Have the oil filters been changed recently?
My TD42 used to stall dead on 10secs after starting it after I replaced the oil filters (with non-genuine) because there was no anti-drainback-valve in them, and if the oil pressure doesn't get above a certain point within 10secs, the engine turns itself off.
OE Nissan filters and the problem went away and never came back.

HTH?

Alex

[mike_nofx]

Have you checked your timing?

Mine used to have starting issues when I first got it, and would stall until I fixed timing.

[tj81]

Fuel cut off solenoid.

The wire to mine was dodgy, and would stall when below a certain rpm.

[Swerve]

SUCCESS

Well after pulling everything apart she still wouldnt run, weird thing was the other day it did run for those 20 sec, timing was 10 degrees etc.

After more searching on the pertronic EI someone had theres set at 14 degrees, as she wouldnt run, moved the dizzy ? and she works !!!!!! working well, just need to adjust the idle and get the timing light out. The stalling was a loose "+"ve terminal on some wires leaving. Also movethe positive for the EI to the ballast resistor.


Now I know she runs will throw some more cash at it my $900 Patrol is going so stoked

[BadMav]

Mate, Good to hear you got it sorted. I'm curious though as to what timing you said someone had theirs set at 14 degrees and wouldn't run. I have dual fuel on mine with the pertronics ign and run my timing at 17-18 degrees BTDC, no worries at all. Don't be fooled into bypassing the ballast resistor with the pertronics electronic ignition either. You WILL burn it out, the total ohms for coil/resistor has to be more than 3 ohms. Also, they seem to be sensitive to voltage drop too, particularly in winter. They need at least 10 volts to fire your coil and if your battery is a bit tired and won't maintain >10 volts while cranking, no spark. I'm only mentioning it because I've spent the last 2 weeks chopping and changing things to try and get mine started on the colder mornings.

[Swerve]

Bad Mav,

When I bought the car it was missing the coil and judging from teh way it had been wired the Pertronics was connected direct to the coil. In the thread I found yesterday they all say to move the peretronic "+"ve wire to the Black/white wire on the ballast Resistor. That is what I have done.

In my other serach on Pertronic someone said 14 degrees, In my issues when I did get it started it was on 10. As she wouldnt start at al since on either gas or petrol. So in my desperation I blindly moved the dizzy, and she's working great. I still need to get the timing light out again and exactly set it, I also havent tested GAS. But at least she is running, will dig up the thread on Pertronic Timing

[Swerve]

OK, Found the thread i was thnking of, was on Patrol4x4

http://www.patrol4x4.com/forum/showthre ... 088&page=4" onclick="window.open(this.href);return false;

Just to make sure is it hooked up to the ignition side of the resistor, it has to hooked up where u see the original black and white wire on that side of the resistor, if all still isn`t good, sounds like u could have a falty pertronix ignitor or it may be something else.

[BadMav]

Yes, I did mean don't bypass the resistor to the coil if using pertronix. White w/ black stripe and pertronix red wires to + on balast res, double red wire to - side of ballast res, single red wire to + side of coil, pertronix black wire (and any other triggers, gas, alarm, tacho etc.) to - side of coil. But the coil ( or coil/ ballast resistor) must have no less than 3 ohms. Just check the resistance on the coil to be sure. Low resistance WILL fry the unit. I run premium in mine as well so I can get away with that much timing but I want to get as much power out of the gas as I can because it's a slug otherwise (well more of a slug ).

[Swerve]

Cool will check the coil resistance, Its a GT40 so should be OK, but will check. Hopefully on teh weekend I can check over the timing and idle speed and fix it up. As the car had sat for 2 years before I picked it up thyis was the first time it was running. OIl light is now on so need to check that before I do anything else, I just think now the engin eis lubricated there is less oil in the bottom ? well see later

But the coil ( or coil/ ballast resistor) must have no less than 3 ohms. Just check the resistance on the coil to be sure. Low resistance WILL fry the unit

[BadMav]

GT40 will be fine as far as resistance goes. It's the GT40R that needs a ballast resistor. But as for the GT40 coil, test it anyway but throw it over your left shoulder and get a good coil if it start to play up. My GT40R was nearly new and the bast@rd was breaking down up top end of the revs. It's gone and in it's place is an Accel super coil. Never looked back.

[Swerve]

Well I bought a new coil and made no differnce. My therory was either the coil or EI so plan was to change to points. As I had nothing original left I sourced a carbie dizzy on Patrol4x4, slightly annoyed with OL as I read the WHOLE far sale wanted thread and wasnt given access.Even added the required PHRASE

Anyhow installed the new points dizzy today, blindly adjusted it got it running, set the timing to 10 degrees and BINGO all working, so stoked