Long Starting with EBL Flash and TunerPro software

[beast94]

I installed an ECM from EBL Flash and tuning with TunerPro software on my '94 K1500 P/U with a 350 TBI. I did not have this problem with my stock ECM and it started as soon as I switched.... I have to crank the engine for about 25-30 seconds when it is cold and when it is at operating temp it will not start at all. I have noticed that it starts as soon as the oil pressure shows just above the red line. Is there a way to tune out the oil pressure switch or is it a problem with the sensor? How would I go about fixing it? Thanks.

[Nasty-Z]

I installed an ECM from EBL Flash and tuning with TunerPro software on my '94 K1500 P/U with a 350 TBI. I did not have this problem with my stock ECM and it started as soon as I switched.... I have to crank the engine for about 25-30 seconds when it is cold and when it is at operating temp it will not start at all. I have noticed that it starts as soon as the oil pressure shows just above the red line. Is there a way to tune out the oil pressure switch or is it a problem with the sensor? How would I go about fixing it? Thanks.

Seems weird that it would have started when you swapped PCM's but , check that the fuel pump relay is getting a "prime" siginal from the ECM .

The pump has two circuits that power it , one is a "prime" command from the ECM that the fuel pump relay gets before and during cranking , the other is via the OPSU (Oil pressure sending unit) , this actually runs the pump as long as the engine has oil pressure.

If the ECM is not commanding a "prime" before and during cranking the engine will not receive fuel pressure until the OPSU "sees" oil pressure and closes that part of the circuit.

HTH

TOM

[EagleMark]

What he said...

94? Does this have an Auto trans and the 2 ECM now? May be a wiring issue.

[beast94]

I was thinking it was a fuel prime issue so I replaced my fuel pump relay with no change. Is there a line item in the software for prime length? I can try that.

[Nasty-Z]

I was thinking it was a fuel prime issue so I replaced my fuel pump relay with no change. Is there a line item in the software for prime length? I can try that.

Is the EBL actually triggering the relay to activate during the "prime" and during cranking ?

I believe pin A1 is the fuel pump relay siginal wire on the EBL wiring , which siginals the relay to activate . I would check to be sure you have a siginal there first .

TOM

[beast94]

Ok, I will check that. It will be a couple weeks before I can do it. Im away from home right now. I will make sure to post back when I get a chance.

[beast94]

What he said...

94? Does this have an Auto trans and the 2 ECM now? May be a wiring issue.

Yes, it has a 4L60E. I had to repin the Engine ECM and splice in the OEM ECM to run my transmission. I am going to be getting rid of the OEM ECM and replace it with an actual trans controler soon. I will double check my wire pinning and wiring.

[beast94]

Seems weird that it would have started when you swapped PCM's but , check that the fuel pump relay is getting a "prime" siginal from the ECM .

The pump has two circuits that power it , one is a "prime" command from the ECM that the fuel pump relay gets before and during cranking , the other is via the OPSU (Oil pressure sending unit) , this actually runs the pump as long as the engine has oil pressure.

If the ECM is not commanding a "prime" before and during cranking the engine will not receive fuel pressure until the OPSU "sees" oil pressure and closes that part of the circuit.

HTH

TOM

How do I check the tune for the the "prime command"

[beast94]

Ok, I talked to Bob at Dynamic EFI and he said that he thinks I have a faild component in the ECM for the priming. He recommended that I swap A1 over to F6 and that fixed my priming issue for now until I can send my ECM back to him for repair. I replaced my distributor, because I was going to do that anyway in about 2 weeks. That fixed my hard starting issue. Now it runs good. Its back to tuning for me! Thanks everyone for you help.

[EagleMark]

Glad you got er done! RBob and Dynamic EFI are excellent products and tech support, really rare to see anything not perfect to come from there, but stuff does happen.

[beast94]

I am having another issue now. I cannot update or program any banks. I have the key on and the WUD says that I am communicating with the ECM, but when I try to update or program any bank, it tells me it failed. The connectoins are good and everything and I can veiw data when the engine is running. What should I look at to fix it. Thanks