Seriously need help

Sabbath

Member
Holding the throttle flat on an EFI car on startup wont have the same effect as doing it on a carb. car, simply because of the way it injects the fuel.


My first thought was that it was possibly a fuel vapour issue. When the car has been sitting, there is a high amount of vapor in the system and not being vented, so the over rich environment makes ignition harder until you've cranked it through and cleared out the system. And with your starting after it's been sitting, if you get it soon enough, there hasnt been time for it to "clog up", but after a while the vapor sets in again.
 
Ok, first thing is did you take it to Holden as there testing computers have a lot more features for testing the ecu, I found out on my ss that the mechanic's one said no prob but holden's one said yep...then I would switch it to gas and when it is cold would switch the ignition on and of 10 times and on the tenth time try to start it. If it starts straight away then the problem is in the injector delivery or air getting in...if it doesn't start I would look at the ecu...
Hope that helps..may also be the air meter...check around where the gas injector goes through into the air intake hose..
 

camperman2010

New Member
Ok, first thing is did you take it to Holden as there testing computers have a lot more features for testing the ecu, I found out on my ss that the mechanic's one said no prob but holden's one said yep...then I would switch it to gas and when it is cold would switch the ignition on and of 10 times and on the tenth time try to start it. If it starts straight away then the problem is in the injector delivery or air getting in...if it doesn't start I would look at the ecu...
Hope that helps..may also be the air meter...check around where the gas injector goes through into the air intake hose..

No i didnt take it to a Holden dealer, they charge like a mally Bull just to look at it.This morning i changed the brake light, same thing, and also changed the MAP sensor, still the same, then on the hwy i flicked it over to LPG and nothing happened and it died,so back on petrol, but when i got home,i checked out the little micro controller for the Lpg under the dash and wiggled it around and the little greed light came on then it started on the Gas, so i went back to my mechanic and found out the positive connector on the micro controller was loose and had come apart fron the circuit board, was just holding on the solder and he said this could be the problem because the positive lead controls the injector pulse for when it starts on the Gas,so he has ordered a new one and getting it fitted tomorrow morning..I really hope thats the problem.
 

Xagtho

Active Member
I didn't realise you were on lpg also, this leaves a few more things to look at, as you have just found, good luck
 

JC807

Member
I dont think it would be the cable because if it was, then it would do it all the time. It only has this issue when its cold...

I would have thought there would be less mechanical resistance starting a warm motor than a cold one. therefore the starter motor might be drawing less current through the cable?

you could try and put a jump lead from the +ve to the starter motor for combined there would be less electrical resistance, and see if that helps. easy thing to try.
 

Sabbath

Member
I would have thought there would be less mechanical resistance starting a warm motor than a cold one. therefore the starter motor might be drawing less current through the cable?

you could try and put a jump lead from the +ve to the starter motor for combined there would be less electrical resistance, and see if that helps. easy thing to try.

It could be internal high resistance in the starter itself.


Sent from here, so you can read it there. via iPhone.
 

camperman2010

New Member
Starter motor is fine. Got the new Safety Switch for the Lpg put in this moring, still same issues...I spoke to a holden mechanic aswell today and he said its the Crank Angle Sensor, apparently the Jackaroos develope a Micro Crack and it WONT throw any codes,or show up on any diagnostic computers because as the engine warms up the Micro crack closes and operates as normal, but when it's cold the crack opens up,so ive booked her back into the mechanics next thursday to fit the new CAS..Dam this is hurting by pack pocket and a good chunk out of my pension.
 

prawns

Moderator
I will cross my fingers for you mate - Crikey it does sound like you've gone through some $$ sofar trying to nail the issue :(

At least you got some spares now though I guess? (old fuel pump etc was ok?)
 

camperman2010

New Member
I will cross my fingers for you mate - Crikey it does sound like you've gone through some $$ sofar trying to nail the issue :(

At least you got some spares now though I guess? (old fuel pump etc was ok?)

so far im out of pocket about $1300, the fuel pump crapped out about 6 months ago, 2 days after i bought the car and the next day the Lpg converter shait its self aswell... well their is only 2 more things to change, the crank sensor and cam sensor which is getting done next week, their is nothing else to replace, done and changed everything under the sun... if this dont fix it, then the car will get put up the back and buy something else, maybe build her up radically stupid for Comp ( small block chev,20" lift,44's ect ect when i can afford extra $$$, slowly bit by bit... ok ok now im dreaming lol :p
 

cloughcarib

Well-Known Member
so far im out of pocket about $1300, the fuel pump crapped out about 6 months ago, 2 days after i bought the car and the next day the Lpg converter shait its self aswell... well their is only 2 more things to change, the crank sensor and cam sensor which is getting done next week, their is nothing else to replace, done and changed everything under the sun... if this dont fix it, then the car will get put up the back and buy something else, maybe build her up radically stupid for Comp ( small block chev,20" lift,44's ect ect when i can afford extra $$$, slowly bit by bit... ok ok now im dreaming lol :p

Mate, I must admit that I have NEVER heard of major issues like this with an Isuzu motor.

Must be the badge on the front;).
 

old_aussie

Banned
I know of one diesel hilux like that the banjo fitting was leaking at the filter , the fuel would drain back to the tank :rolleyes:
 

tankbloke

4x4 Earth Contributer
I would look at the ecu...
Hope that helps..may also be the air meter...check around where the gas injector goes through into the air intake hose..



Thinking along the same lines as Chris......ecu.
You could have an adaptive mapping problem. To test for it, try disconnecting the vehicle battery for a few minutes, than reconnect and start it back up. If it then runs ok on petrol, it would indicate that your lpg running is upsetting your petrol ecu settings. (Disconnecting the battery resets them).
Make sure you have any radio code no's etc for after you reconnect your battery.
May be no help to you but worth a try and only costs a bit of time.
Goodluck.
 
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pistonbroc

New Member
dont like to be a downer, but if the cranking voltage is that high it has to be a compression problem. Imagine cranking it with the spark plugs out, no load on the starter, would mean little current draw, and therefore high volts when doing a cranking test. I hope it is just the crank angle sensor, but it dont look good.
 
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