[Dragzilla]

Just when I thought I’d gotten the hang of this thing, the next one kicks me in the nuts. :smt088

LSX, with a Dominator EFI. It cranks, has a RPM signal but it won’t run. All it does is kinda softly burble fire in the exhaust, nothing violent or anything... Just a soft rumble.

58X, with a 1X cam sensor (set up just like my other car sitting right beside it) grounds to the heads, chassis, yada, yada. It will not even run when I try bank to bank mode. Fuel pressure/pump primes fine, I checked the color codes to the coils... They are OK and I’m using factory GM coil/pigtail harnesses. ODD going to ODD bank (1357) EVEN going to EVEN bank. (2468) Fuel pressure at prime= 45 psi.... Any thoughts? Could I have the fuel map that far off that it just won’t fire? I checked the plugs and they are not fuel fouled that I can see. Not wet or anything. Thoughts?

 

[Dragzilla]

Here is a engine pic. (Ignore the misc wires, I've added a few extra during trouble shooting the problem and I've not finished a few other things.

Sensors: Holley 3 bar map, and all Holley pressure sensors or GM sensors... Everything is new.

 

[Doug F]

58x/1x isn't a factory setup, you need to set it up under custom, with the right parameters.

58x/4x should be the factory setup. I'll look later and post the right config or tomorrow am.

How is the ign configed?

 

[Dragzilla]

58x/1x isn't a factory setup, you need to set it up under custom, with the right parameters.

58x/4x should be the factory setup. I'll look later and post the right config or tomorrow am.

How is the ign configed?

Yes. Custom, GM 58X, 1X cam single pulse, Digital falling. 3.0 ms on the coil dwel.

 

[Doug F]

I don't have my notes with me. Dwell should be 3.5 for LS7 coils, 5.0 for LS2 coils, not sure what you have.
Did you put a timing light on it assuming you have a pointer?

 

[Dragzilla]

I don't have my notes with me. Dwell should be 3.5 for LS7 coils, 5.0 for LS2 coils, not sure what you have.
Did you put a timing light on it assuming you have a pointer?

I tried 1.5, 3.0 and 5.0... I'll try 3.5 next. And I just checked the fire, good... I'll hit it with a light next.

 

[Dragzilla]

Timing light won't flash for some reason during cranking, but I know it has spark... Not sure what the problem is there. My RPM signal is pretty slow (around 138 RPM) could that be the problem? It's a high torque starter that's slow as hell... :-/

 

[LS1NOVA]

If what's been said above is resolved and it doesn't start try bumping the fuel table up a couple points in the area where its cranking.

 

[Qwik_SN95]

Nothing helpful to add but Damn that whipple looks good up there.

 

[Dragzilla]

If what's been said above is resolved and it doesn't start try bumping the fuel table up a couple points in the area where its cranking.

I looked at that. The highlighted cell (orange dot) is not moving yet because it only starts moving/adjusting at 500 RPM... I'm cranking at around 138 RPM.

 

[Doug F]

You did a TPS autoset?

 

[Dragzilla]

You did a TPS autoset?

Yep... Bunch of times.

I'm beginning to believe it's fuel related, but I don't know why. Fuel pressure at the rails is 43 PSI. I have two Holley 1800 pumps. (only one running now) with a -12 feed and a -10 return. I even bypassed the Holley control circuit and powered the pump relay from the battery and it still won't run. But I just checked the plugs again and they are not wet like you would think with all the cranking I've been doing... Not wet at all.

 

[Dragzilla]

One other bit of info before I call it a night. I put NOID lights on the injector connectors and they are working so that's not the problem... Gonna sleep on it tonight and get back at it tomorrow. Thanks guys for all the info so far...

 

[rick90lx]

I had really slow cranking like that too and realize I had a ground from the battery to the frame that wasn't connected. When I fixed that you would have thought I switched to 16v. I know you said you checked grounds but I'm just throwing that out there. Maybe do an ohms check to make sure the grounds are all damn near zero.

 

[Brillko]

Add fuel in your cranking table. You find it under fuel/startup enr.

Thats your start fuel. You can also do a Fuel Prime under System screen. Use 200% for starters.

See if you have luck. Buy a better timing light that works on low RPM.

 

[Danny Cabral]

Add fuel in your cranking table. You find it under fuel/Startup Enrichment.

Thats your start fuel. You can also do a Fuel Prime under System screen. Use 200% for starters.

Correct, there is no "cranking area" on the Base Fuel Table. The Base Fuel Table & the Base Timing Table aren't active while cranking/starting the engine. Under 400 RPM (or whatever your "Crank To Run RPM" is), the ECU only looks at the Cranking Fuel (lb/hr) Table, the Cranking Timing value and the IAC Parked Position %. As soon as the RPM reaches 400+ RPM, the ECU looks at the Base Fuel, Timing and Idle Speed Tables.

You can only tune the Startup Enrichment parameters after the Learning has self-tuned the Base Fuel Table and if the Coolant Temperature Enrichment & A/F Ratio Offset tables are acceptable. This is because the aforementioned parameters & tables are modifiers of the Base Fuel Table. Exception: Cranking Fuel lb/hr and Cranking Timing, because it functions independently under 400 RPM (or whatever your "Crank To Run RPM" is).

In the Help Contents of the EFI software (Step-By-Step Beginners Tuning), look
at the "Idle Fuel vs. Temperature" graphical representation - figure 8, section 5.1.

http://www.yellowbullet.com/forum/showthread.php?p=21211498#post21211498 (Similar Forum Thread)

 

[Dragzilla]

I have plenty of fuel in the cranking table but I added more to be sure... No help.

 

[Dragzilla]

Add fuel in your cranking table. You find it under fuel/startup enr.

Thats your start fuel. You can also do a Fuel Prime under System screen. Use 200% for starters.

See if you have luck. Buy a better timing light that works on low RPM.

The fuel system prime tab goes away when you go "custom"

 

[Dragzilla]

Checked everything again and it all looks right on the computer. I also swapped out the ECU so I now know that’s good. And I double verified it by putting it on another car and it fired right up. :-/

 

[Danny Cabral]

The fuel system prime tab goes away when you go "custom"

I don't understand, "Custom" what? We're referring to the the Fuel Prime Percent in Engine Parameters (System ICF). Is the check box enabled? I just entered "Custom" as the Fuel System Type, and it's still there.