92 bighorn 3.1 engine lt on, speedo off?

[kage]

I have a 92 bighorn irmsher 3.1 petrol with 80,000km's.

problem one.

Sometimes when idling, it races up and down to where it will it will die if in neutral.

Sometimes when travelling down the road, the speedo will drop to zero and the engine light goes on.

All else seems fine.

Any suggestions?

Cheers,

KJ

[geeves]

First question, Auto or manual trans? If auto it sounds like the engine is stopping while driving so probably the same cause as prob 1.
First choise batterey is it in good condition and the leads tight. Second choice computer (expensive).
Little confused the petrol irmshirer was 3.2 liters not 3.1 unless yours is American spec with a chev based engine but these were sold as Troopers. Your email address sugests your in California. The speedo is also a hard question as its mechanical so not affected by battery etc

[PeterSchurms]

Hopefully its a loose connection as Alan pointed out. I found a loose earth lead to the chassis on a Suzuki that was the root cause of some really weird things. eg Temp gauge jumping, tacho jump or reads nothing, poor starting.

On some jap petrol engines there is a electrical controled needle valve that governs the fuel rates at idle. If its damaged, worn or disconnected the truck may do some weird things when idling.

I am not familiar with the isuzu 3.2 or 3.1 petrol engine. So I am not sure where it's specifically located.

Just a couple guesses anyway.... good luck

Pete

[kage]

Thanks for your help, Sorry about the confusion.

It is a 3.2 Petrol, Automatic Trans. I am NZ.

Battery is in good shape, leads tight.

How can I check my speedo cable?

Any thoughts on where to start looking for the potential loose ground?

As for the electrical controled needle valve, does anyone know where to look?

One other problem I forgot, the ignition relay doesn't always work, It wasn't the relay (this was good) The only way I could fix it was to bypass it with a push button connected to each side of the relay, manually closing the circuit to start. Once again, this is spuratic. like It won't happen for 3 or 4 days, and then it might happen 3 or 4 times in a day. At one stage, it seemed that pushing the headlight wiper button would help?

I took it to an auto electrician, but it worked when he looked at it.

Any other thoughts?

Cheers,

KJ

FYI the two problems don't seem to happen together, and are spuratic.

[geeves]

My father in law had similar things happening in his Disco It took over a year to track down to the computer mainly because nobody would buy a computer at $800+ untill they had exhausted every other posibility. I would be going over the engine and trans with a torch and spanner tightening every eath lead and disconecting and reconecting every harness conector you can find This will clean the connectors and might help.Expect to take at least a couple of hours to do this. No garentees sorry