I just bought a couple Troopers with the 2.8l V6. My 1990 had a terrible oil leak. I replaced the Dist shaft O-ring and reinstalled. Upon install I think my marks (grease pencil) were a little off. I want to shoot the timing but don't know what, if any, hoses need to be plugged or? Little help?

A little tech tip: Replacing the Dist. hold down clamp bolt with a stud is a good idea, but you still have to contend with a nut that can disappear into the abyss. Placing the bolt through the clamp then installing an O-Ring to the bolt will hold the parts as one unit. Works great!

I will have to pull the procedure this evening when I get home, but I believe that rather than plugging hoses, the procedure involves jumpering two pins in the connector under the center console.

Thanks Jim, I've been trying to track down a set of factory manuals for the 89 and 90. Until then any help is greatly appreciated.

Even though I no longer have an Isuzu, I still have my FSM since I am still a moderator here.

There is a diagnostic connector under the removable tray in the center console. Two pins on the connector need to be jump to put it in diagnostic mode, which allows one to set the timing correctly. I am not sure but I believe that it is pins A and B which need to be jumpered. The FSM shows that.

To be honest, years ago I found a small GM diagnostic device which plugs into the diagnostic port. I even kept mine next to the connector in the console. Once I found that device, I never manually jumpered the pins again.

I appreciate the info. Can you give me the name/model/make of the diagnostic device? I may be able to track one down. It might be handy given I have 2 of these Troopers that will be "Service Needy" until I get them dialed in. Also, do you have a line on where to get a FSM for the 89 & 90 2.8l Troopers?
Thanks again for your time and assistance.

I don't have the device any more so I can't help you with that. I know that I found it at an Auto Zone or some such place. Should be the same as one for a late 80s GM or Chevy.

You might contact Jerry LeMond to see if he has any more FSMs. It is actually a set of three manuals - the base FSM, an addendum for the V6 and an electrical system manual.

Try contacting Jerry at [email]jlemond@bellsouth.net.[/email] Hint - his vision is getting pretty bad, so it really helps him if you format your email in 14 point type.

(Jerry was a lead instructor for the factory Isuzu school and also bought up a lot of inventory from dealers as they went away.

I'll check Autozone and get a hold of Jerry.
Thanks again Jim

Actually, when you jumper the 2 pins in the ALDL (diagnostic plug) you put the ECM in "read trouble codes" mode.

To be able to check/adjust the spark advance, you have to disable the Electronic Spark Control (ESC).

To do this, go into the console (likely under the front pop-out tray) and find the wire that has an inline connector. Should be the only one in the console like that. It'll either be a white wire with black stripe, or black wire with white stripe. As I recall, mine was wht/blk.

Normally this wire is connected to enable the ESC. What you'll want to do is unplug the wire from itself.

This will do 2 things: energize the "check engine" light/set a trouble code, and disable ESC.

Then you'll be able to slap a timing light on #1 cylinder and read the scale on the timing cover.

Note that it'll idle a bit doggy with the ESC wire disconnected, but that'll go away when you reconnect.

BTW if you adjust the timing to around 12 deg BTDC or so on a stock 2.8, it'll run just a bit better.

Don't forget to reconnect the ESC-disable wire when you're done! The check engine lite will go off, and the trouble code will persist in the ECM for a set number of start/restart cycles, but will eventually clear.

HTH & let us know how it goes...........ed

Thanks, Ed. It had been a while since I had worked on an Isuzu and my memory failed me.

Note to GreaseMonkey - there is very little about Isuzus that Ed does not know.

Thanks for your help Ed. I read this, goter done and never responded. Thanks again.