Chevy & GMC Vans

Gary, when you did the column swap some wiring got moved. I think there's a clue there somewhere. I'd start checking continuity.

Well we got the idle thing resolved.Swap out the IAC motor and the 65lb cop car injectors and bam-it ildes like it should.I think this is a case of a mod that wasn't done correctly with the computer.Now we move on to the swap to Ole Yellar with the trans rebuild done first.BTW-I am planning to build a killer tranny with TCI componets.More to come later this wk about that.

Thanks all for your suggestions,


Gary

what about the timing?You check that yet G?

That's a good point,but as I said,we got it to idle normal with a change of the IAC motor,swapping out the Cop car injectors,and a different fuel TBI reg.

cool.....

Well now that I am getting the engine out of the donor with the wiring harness,and although I got the idle down,I never got the data link to hook up with the computer.Kind of looks like I'll be checking the harness one pin connector at a time.Any suggestions???.

The weird part about it is the engine would start and run,but wouldn't scan.I would think if it had a short on one of the sensors,that would show up during a scan,but it wouldn't scan at all.All it said was it wouldn't commuciate at all.That was with two different computers too.Still need your support to figure that one out.

Gary, Is it OBDI or OBDII? I had the same problem with a OBDI system and never did figure it out. The motor ran just fine so I let it go at that.

Smiliesafari wrote:Gary, Is it OBDI or OBDII? I had the same problem with a OBDI system and never did figure it out. The motor ran just fine so I let it go at that.

OBDI with a TBI.It does kind of bothers me because if I have a issue at some point,I don't want to be left with shotguning parts to fix it.

It's gotta be an open circuit between the diagnostic port and the 'puter. As was mentioned earlier, you'll have to check each of the wires one at a time...

peter wrote:It's gotta be an open circuit between the diagnostic port and the 'puter. As was mentioned earlier, you'll have to check each of the wires one at a time...

Will do.Going to label each lead too.This is going to put me on the fast track on a learning curve.Got to check to see if what Rob gave me covers the wiring diagram.If not anyone got suggestions on line where I could follow one for a 1989 Astro??.

Gary, I've got the electrical manual for the 89 Astro, so wiring diagrams won't be a problem. Let me get into them and I'll send you the wire colors and designations shortly.
But, for what it's worth, the data line out on my '89 was intermittent as all hell. It was tough to get real time data by use of a laptop while driving. I never did figure it out, but it doesn't matter now as I've carbed the van. However, the check engine light always seemed to flash any code that the ECM had, so I didn't worry much about it.

First I would figure out if the real problem is the data port, the scanner or operator error. Did you try the paper clip method to check for codes? Did you try this scanner on another TBI van? Did you have the ignition on? There are only a few wires hooked up to the port so it should not be too hard to track them down.

Gary,

Here's what I got from the 1989 wiring manual:



Lockdoc brings up some good points. There isn't much to the connections between the ALDL and the small plug on the ECM. Make sure that you get a good connection when shorting ALDL connector pins A to B when you want the SES light to flash the codes.

Thanks guys.I'll post and picture what I find.