Engine stalling and starting randomly

[TARK_]

Hello everyone,
Unfortunate owner of an 92' 4Runner with the 3.0 V6.
It is GPL modified, very bad for the motor itself.
The GPL modification was revised by a "professional" mechanic who had changed everything, but it is very bad work...

Yesterday, i done a 5Km ride to the nearest shop.
No problem to start the engine, nothing was weird. But when it came time to return, it stalled miserably at a stop sign, and it was impossible to restart the engine.
Now it starts when it wants, and stalls very quickly. As soon as it stalls, it refuses to restart, and I have to wait a bit before it restarts.
It sometimes runs for 2-3 minutes, sometimes only a few seconds.

I checked my spark plugs, my distributor, my ignition coil and also my igniter.
After searching the forum, the only solution I see is the ECM.
I can't find it in the engine compartment even though the repair manual schematics shows it at the bottom left.

Maybe someone had the same issue ?
Or if you have any ideas or leads ?

Thanks to everyone who can see this, I'm desperate...

 

[fourwd1]

The ECM (and the COR (IIRC)) are inside the cabin behind the passenger side kick panel.

 

[AuSeeker]

Maybe it will help us help you IF you tell us exactly what is a "GPL modification", sometimes I have a hard time with acronyms??

Even Google is having a hard time with this acronym!

 

[fourwd1]

^^^^ He's right. I meant to ask that too.

 

[TARK_]

Sorry, I'm a bit stupid I didnt translate the acronym. In English it is LPG, liquefied petroleum gas. We have this everywhere in europe, and it is compatible with gasoline cars.
The extra pipes on the right of my engine are for this additional system.

 

[AuSeeker]

We also have this modification but it's mostly done on commercial vehicles.

So I don't know much about what all makes it work, I'm guessing the gas is getting shut off, maybe a sensor, a valve or the metering device has failed.

Since you have a lot of vehicles using this type of system over there, there should be numerous mechanics familiar with these systems that could solve the issue.

 

[fourwd1]

Oh yeah, there's an LPG conversion for the 4 cyl carbureted 22R in my '84.
The main advantage for me was the steep angles it would operate at when off-roading.
I found that if I adjusted the float level in the carb out of spec it worked fine, so I never did the conversion.

Good luck!

 

[TARK_]

I want to add that the problem is the same if I use LPG or gasoline. It is not fuel related problem...

 

[fourwd1]

I'm no expert, but I lean towards what [MENTION=149207]AuSeeker[/MENTION] said, it sounds like a fuel delivery issue

... I'm guessing the gas is getting shut off, maybe a sensor, a valve or the metering device has failed.

If you have the same problem with gas and LPG, it sorta eliminates the system parts they don't have in common, so look at areas they do have in common.

Make any sense?

 

[TARK_]

Thanks for the lead !
I will seek this tomorrow, I'll let you know if I find something.

 

[fourwd1]

Thanks for the lead !
I will seek this tomorrow, I'll let you know if I find something.

Let us know how it goes, this is the most interesting topic that's come along in awhile :cheers:

 

[TARK_]

I checked all the injection system (it is the only thing in common for the fuel delivery), all seems to be functionning correctly.
Another thing that is weird, the Malfunction Indicator Lamp will come on when the ignition switch is turned ON and the engine is not running, but when the engine will not start, this lamp is not lit.
Maybe it can help to find other leads...

 

[AuSeeker]

I checked all the injection system (it is the only thing in common for the fuel delivery), all seems to be functionning correctly.
Another thing that is weird, the Malfunction Indicator Lamp will come on when the ignition switch is turned ON and the engine is not running, but when the engine will not start, this lamp is not lit.
Maybe it can help to find other leads...

I'm not sure what you mean by "Malfunction Indicator Lamp" we don't have a light labeled or called that here in the USA, is that the "Check Engine Light" i.e. it looks like a little engine?

 

[TARK_]

Yes, this is the orange engine icon. I tried to do the troubleshoting from the manual, but nothing happens. The engine icon does not power on...

 

[fourwd1]

I'm not sure what you mean by "Malfunction Indicator Lamp" we don't have a light labeled or called that here in the USA, is that the "Check Engine Light" i.e. it looks like a little engine?

Yes, Toyota refers to it as the MIL in their manuals.

And that is the correct procedure, and it usually works, I've done it before.
Make sure you are install a jumper between the correct terminals of DLC-1.
And the Ignition switch is in the ON position (not running) before installing the jumper. IIRC the MIL should come on briefly as soon as you put the Ign sw in the ON position.

Maybe the LPG conversion has some wiring changes that might be affecting it?

 

[TARK_]

I retried it today. The MIL shows up randomly when I turn the ignition switch on.
When the MIL stays on, I install the jumper but il flashes every 0.3s, so "no malfunction".
All seems to be related to the ECM, if I have well understand what is it for...

The other problem is that the LPG conversion has been done by an older owner, so I can't go there to ask them how they have installed this... The only thing I see is that little box, but nothing changes when I unplug it.

Nobody had any issue with the ECM acting like this ?

 

[TARK_]

Hello everyone,
Just a little update, I have found a new ECM and installed it.
Now everything just act normaly, all was from this module.
Thanks for all the informations !

 

[fourwd1]

Great !
It's amazing you could find another ECM.

 

[nye307]

Great !
It's amazing you could find another ECM.

I have a similar problem going on with a recent purchase. Haven't started troubleshooting yet but I understand ECM is one of the potential causes. How specific is the ECM to the vehicle? Like does it have to be within the same year or will any ECM within the same generation with similar options work? I've got a couple of really good Yota yards near me so I'm guessing they'll have something if my issue comes down to this.