I'm still struggling to get a three year TPI swap engine started. It's a "crank no start" scenario, and is listed within this DIY prom heading as:

https://www.thirdgen.org/forums/diy-...vs-number.html

I'm trying to eliminate or pin down my 730/prominator ECM combo as the root of the problem. I would appreciate hearing from anyone with the capability and willingness to hook up my 730/prominator unit to your test bench to see if it is functioning, fresh, fried, or just half baked.

Particularly I'd like the Injector and Distributor pulse areas tested as my injectors will fire manually but not by computer control. (My continued thanks to those responding to my other inquiries)

If my question is inappropriate for this area of the forum as "begging", then I apologize to the moderators. I'm frustrated with this thing, and need help.

 

I could test it in my car if you want to send it. My bench could only do partial test.
I know the wiring and setup in the car is correct.
It sure does appear that you have some kind of power drain during cranking.
DRP = Yes (fuel pump runs and continues to run during crank)
Noid light = Yes but no fuel (very odd)
Fuel psi = good

If noid light was truely flashing (not just changing intesity) you should have fuel on the plugs. That is the bothersome point.

 

I have test guage hooked up to the fuel rail at the schraeder valve. It indicates 46-47 lbs. The fuel pump runs initially for about two seconds, then stops I hear the relay kick out. After that, pressure stays relatively constant when cranking. To me, that's a another indication of injectors not firing. If I manually trigger an injector, the pressure drops, and does not come back up, as the fuel pump doesn't seem to kick on again.


I will gladly take you up on your most kind offer to test my ecm. I'll send a PM to you later tonight to get a shipping address. Right now, I need to get my butt ( and the rest of me as well) off to work. THanks again, Dave Buchholz

 

Quick test to check if the ECM is seeing DRPs: once the pump stops after the initial 2 second run. Give the key a quick tap (crank engine) and listen for the pump. It should turn on, run for 2 seconds, and then stop.

Can double check by giving it another quick tap of the key. Each time you do this the pump should start up, run for 2 seconds then stop.

If the ECM does turn on the pump then the ECM is getting and seeing DRPs from the distributor. In this case it is possible that VATs is enabled in the calibration. Which is preventing the injectors from pulsing.

If the ECM does not turn on the pump each time, then either the distributor, ECM, or wiring/connectors between the two are bad.

RBob.

 

Ahh, the pump not running will cause all this to happen.
If you are getting DRPs (indicated by flashing noid) but no fuel is present then the fuel pump relay could be wired incorrectly or is just bad.
Checking for voltage at the ECM pin "A11" IIRC.
Can also verify by looking at the FP voltage on a datalog because it is wired in to E13 input.
You should also have an oil pressure switch that "should" turn the pump on once cranking long enough to build oil pressure.
This switch could also be miswired or removed.
Before taking anything apart you may want to reconfirm your good on those points.

 

I have a test bench, but am also in Canada (Though almost literrally just across the the border in Southern Ontario), so shipping would be expensive, and probably have duties on top of that. :facepalm:

I don't see the ECM itself being the issue, since you say that no combination of ECM, or MEMCALs, tested, as indicated in your other thread allow the engine to run. It's unlikely that multiple ECMs are faulty, unless they all have the same fault caused by an external problem from the same vehicle.

 

JP, Dave mentioned that the pump does the 2-second run at key-on, engine-off. So the ECM driver, wiring, relay and all that is OK. Just need to find out if the ECM is seeing and responding to DRPs.

Depending upon what the fuel pump does each time the key is tapped will tell us what needs to be checked next.

RBob.

 

Very true but...
What if the power to the relay and oil switch is interrupted when cranking?
That could be difficult to see unless specifically looking for it.
Would work with initial DRP bump with key on but would do nothing when it really counts.
I hope it is because everything else does seem to be working because he gets DRPs if the noid light flashes.

 

Please check the thread about cylinder codes for test responses. of 06/23/09