100 wont start - possible immobiliser issue? - FIXED

[adrianr]

I moved the cruiser yesterday to do some work on the RAV. As always cracked with a flick of the key.

However, when i came to move it back later on it cranked for a while without firing - just like if an immobiliser was on.

I never use the large key fob and buttons to lock it, just the key.

So i grabbed the fob and locked and unlocked it. still no start. so i gave it some throttle and it fired into life.

was ok for the rest of the day bar later in the evening the alarm had armed itself and thus went off when i opened the door to drive. so i used the fob again to switch the alarm off. started as normal though after that. I wonder if the alarm arming itself is a clue.

This morning I went to start it and the old tug cranked again without firing. so i used the fob to lock and unlock it and this time it refused to fire. have given it several burst on the starter and some throttle and nothing. the security light on the dash goes out when i put the key in the ignition and turn it.

i have ordered some replacement batteries for the alarm fob - duracell 1616 just in case it the voltage is getting low. these will be here monday - no where local has them in stock. am going to detach the negative terminals on the battery and leave it for thirty mins. then shall see if it start. ill check the voltage on the batteries. given the way it was cranking rapidly i reckon they are fine. but worth checking.

as an aside i noticed the truck hunting a little on light throttle the last few days. i replaced the fuel filter this morning before trying to start it. the pump on top pumped up quickly to being hard so cant see it being that.

any ideas you can help with would be gratefully received. thank you.

 

[adrianr]

Update.

the truck is now running.

leaving the batteries off for 45 mins whilst i cleaned up the brakes and handbrake on the Rav 4 made no difference. still would not start.

so off for a hot drink and let my mind wander.

the previous owner fitted airbags to the rear springs, with an adjustable psi via a threaded bolt under the centre console (drink holders area) and a boost gauge to show the psi. wiring pretty heath robinson (as was the wiring for the changeover valve for the second tank that failed leaving me with a problem one wet night, but that’s another story and wont happen again a now have 2 brass ball valves -one for the feeds and one for the returns. under the bonnet. it’s a touch more hassle but they wont fail.)

There is a cheap and rather noisy air compressor under the bonnet that runs to keep the bags topped up. i had noticed the other day it was sounding tired so i was going to investigate. reason for the meander is that i noticed when the truck would not fire the compressor was not running. normally it will come on when you first start - as the ignition is turned but before you engage the starter.

when i examined the wiring one of the earths was pulled apart. once i fitted a new earth the compressor started as it should. so i thought what the heck lets see if the old truck starts, and to my surprise it did.

the earth runs from a control module between the fuel filter and the battery. previous owner had run the compressor earth to the bolt at the top of the control module and an earth on from there to a bolt into the body. without the earth from the control module the truck wont start. i have now replaced the earth with a thicker cable and routed the earth for the compressor straight to the earth on the battery. truck seems fine now. will report back if the fault happens again.

 

[Tractionman]

Well done Adrian, it's always a bastard when involved with someone else's bodges, they should leave things alone they don't understand, and install to a competent level.
Glad that it was relatively easy this time.

 

[adrianr]

Well done Adrian, it's always a bastard when involved with someone else's bodges, they should leave things alone they don't understand, and install to a competent level.
Glad that it was relatively easy this time.

Thank you. I am glad too. I was not looking forward to investigating immobiliser problems.

I agree with what you said sbout bodges.

I was just sat here thinking about the job and decided i wanted to redo the earth wire i fitted. So I have redone it with some twin core I had spare from fitting an electric walbro fuel pump to that old mercedes I had, better crimps and then heat shrink over the lot at the ends. at least now i know a good way to disable the truck if i want to leave it parked up for a good while.

 

[uHu]

Update.
.....
the earth runs from a control module between the fuel filter and the battery. previous owner had run the compressor earth to the bolt at the top of the control module and an earth on from there to a bolt into the body. without the earth from the control module the truck wont start. i have now replaced the earth with a thicker cable and routed the earth for the compressor straight to the earth on the battery. ....

This control module, is perchance the EDU, which is a kind of power supply for the Spill Control Valve on the IP? It sits just to the rear of the fusebox. Ground connection to the EDU, and connection from EDU to SCV, has always been a potential problem area on the hdj100.

 

[adrianr]

This control module, is perchance the EDU, which is a kind of power supply for the Spill Control Valve on the IP? It sits just to the rear of the fusebox. Ground connection to the EDU, and connection from EDU to SCV, has always been a potential problem area on the hdj100.

Thank you Uhu. that’s interesting. the earth is now good but i have to give it some throttle to start it first thing in the morning or after it have been parked up for a while. what would be options for repairing / replacing? I'll do some digging through the forum as well cheers.

 

[adrianr]

I woke up in the night with the thought that i should make the earth for the EDU a lot more beefy. So made up one out of some cable from my heavy duty extension lead. Three core. The truck started immediately this morning at -3c. and again this evening having sat all day. it is -3c again. the power heater is one so not sure if that is helping. i shall monitor and report if things change.

the challenge now is lock are frozen. i gently heated the driver's side this morning with a hot air gun. then applied a liberal amount of gt85 through the key slot. and came out tonight to find door lock frozen again. key goes in but wont turn. thankfully i had the remote fob with me. any suggestions gratefully received.

And the number plate light stopped working so I shall replace that in the morning.

 

[chadr]

...the challenge now is lock are frozen. i gently heated the driver's side this morning with a hot air gun. then applied a liberal amount of gt85 through the key slot. and came out tonight to find door lock frozen again. key goes in but wont turn. thankfully i had the remote fob with me. any suggestions gratefully received.

Do you need to lubricate the internals of the lock and lever mechanism- not just the "keyhole" bit? - probably need to do this from the inside, so might require removal of the door card.

However, if it works fine using the remote fob...?

 

[Tractionman]

If it's frozen internally again, that would indicate wet/moisture from de-icing last time ?
When you unfreeze it again, squirt loads of wd40 in there through the straw until it dribbles out, inserted as far as you can in the lock, pushing the outer gate aside to displace the moisture and work it around a few times operating key.

 

[adrianr]

If it's frozen internally again, that would indicate wet/moisture from de-icing last time ?
When you unfreeze it again, squirt loads of wd40 in there through the straw until it dribbles out, inserted as far as you can in the lock, pushing the outer gate aside to displace the moisture and work it around a few times operating key.

Thanks. I will do that again in a bit. if it does it again overnight ill pull the door card off. it does work on the remote fob.

 

[adrianr]

Truck is starting as it should now, every time. So it appears the poor earth, and the 2 inferior replacements were the culprits. i might keep my fingers crossed in my pocket for another few days!

 

[adrianr]

Have loaded up the front door key locks with plenty of gt85.

 

[adrianr]

Do you need to lubricate the internals of the lock and lever mechanism- not just the "keyhole" bit? - probably need to do this from the inside, so might require removal of the door card.

However, if it works fine using the remote fob...?

Thank you.