Hey all, wasn't exactly sure where to post this. Picked up a TPI car and it seems to only run right when manually advance the timing to 15-20 degree. When you unplug the distributor single wire, set the timing to 6 degrees, turn the car off, wait 10 seconds, plug the wire back in, and it seems like the timing isn't moving at all from the 6 degrees at idle until you give it some throttle. This seems odd to me. Also the check engine light will not turn off. I've tried to read the codes via a the A and B port with the key on and engine off and nothing happens. It just stays lit 24/7. Any ideas?

 

I assume your getting your timing w a light off the timing marks off the balancer. The balancers are 2 pieces and are know to separate and slip. Does the car run good w the timing @ 15- 20?

 

Yeah, painted it with white paint so it's easily visible. I should also mention the tach stays pegged at 7k rmp when I turn it on as well. I'm leaning towards replacing the distributor assembly, if that doesn't get it then I guess I'll replace the ECU

 

I know a guy that sells NOS GM distributor assemblies, and I would love to sell you one. But I think I'd do some more troubleshooting before and be leaning toward an ECM problem.

Maybe @Tuned Performance can help out with some troubleshooting ideas.

 

Sounds like two issues, tach board in the instrument cluster is faulty. The running your seeing 15-20 with est connected or that’s the base then it’s around 35 with est plugged back in?

 

I'm setting it to 6 with the est wire unplugged, then when it's plugged in it doesn't move from 6 at idle unless I give it some gas by hand at the throttle body in which it moves to what I would say is 15ish. I don't think it's getting to a full 35. I'll have to double check that later today. If I have time. Also when I set it to 6, it starts and dies like a carburator when it's cold and the choke isn't set right. Doesn't run remotely right until it's completely warm.

 

Ohm est to Ecm d5, it should advance to 15-20 at idle depending on lv8

 

Btw do you have a stored code 42 ?

 

Ok, so I tried the paperclip method and the light just stays completely solid when I key on. So I bought one of these thinking it might work and it does nothing as well which is why it's leading me to believe I have a computer issue. No beeps, flashing, nada, service engine light just stays solid. Oh, and the radiator fan stays on no matter what.

 

That’s kinda funny, if you open up that tool it has wheel weights and is just a switch that connects a to b. If your wiring and ground at aldl checks out i would say it’s a bad 1227165 ecm.

 

To be honest before I got my Snap-on Scanner, I've poked the paper clip into the wrong terminals before. I would have loved to have had that fancy paper clip in a box thing back in the day. I don't see as good close up these days as I did back then. Even then, I didn't see all that good close up so if I didn't have a scan tool today, I'd have that thing you bought as long as it was cheap.

With the Check Engine light being illuminated all the time, it not going into diagnostic mode and flashing code 12 at you 3 times when you jumped terminals A & B, and the ECM not taking over proper control of the engine timing from the ICM I figured it would be the ECM or a wiring problem related to it.

The tach pegged at 7k is probably an unrelated problem.

Tuned Performance normally has some good 7165 ECMs for sale you could buy off him after you have troubleshot the ALDL wiring.

 

You can ohm the ground and a9 continuity. I do have 1 1227165 ecm but unfortunately it’s an untested unit .

 

Yeah, I tried the paperclip. Didn't work. So just to double check I figured this thing was only 25 bucks and came with a book for OBD1 codes for every gm. So I figured why not just to rule it out. What do you guys think about an remanufactured ecm? I see those online. Worth a shot?

Also I noticed when I drive about occasionally the check engine light flickers on and off briefly. Whoever owned this car did some silly things to it as per usual. I'd really like to retain the factory tpi system. I went ahead and had a chip burned that would tune out the emissions systems just so I could rule them out. If that doesn't turn off the light I'll order an ecm from somewhere. Probably going to do headers anyways and get rid of all the a.i.r. Tubes to clean up the engine bay. Is there any specific wires I could look for? Maybe a ground that could be causing the ECM to act screwy.

 

Cardone might have some back in stock 🤷‍♂️
they can be hit or miss on quality control

 

If I ohm the ground, and a9, what will this tell me? Sorry, I'm not the best at wiring and understing it. I can attach two wires and trace colors. That's about about as knowledgeable as I get lol. I assume this will tell me if there's a problem with the ground?

 

The command to go into diagnostic mode requires B to be grounded. So if the aldl A isn’t a good ground or an open in the line going to the ecm you’re not just throwing parts at it .

 

Ok, that makes sense. Can I just do a makeshift ground to B then just to test that out and see if that causes my check engine to flash codes at me?

Also, holy cow why is the 7165 computer so expensive lol. I'm trying to avoid going the aftermarket EFI route, just because I have never had a TPI car. I've had a Holley sniper setup, and an aces EFI setup, so I thought retaining the stock tpi stuff would be neat. If I have to pay $300-500 for an ECU.... I'm kinda a third of the way there for a whole new EFI system.

 

https://www.oreillyauto.com/detail/c...t-camaro?q=Ecm

might see their return policy if it doesn’t work, ground is ground

 

https://www.oreillyauto.com/detail/c...q=Computer+ecm

 

A few inexpensive options

 

Thank you.

 

New developments. I installed the new chip just for giggles. At idle the check engine light started flickering, then went out. As soon as you give it throttle the light comes back on. Still can't check codes. The chip I had burned removed the need to run emissions. Car runs significantly better after tuned chip install. Fan still stays on, still can't read codes.

Just to be sure, this is the timing wire correct?

 

Just to update this thread Incase it helps someone in the future, turns out it was indeed a dead computer. Ordered a remanufactured one from eBay for $280 and it fixed all of my issues. Fan now kicks on when it's supposed to instead of just being on all the time. Check engine light is off.