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-   -   Cranks but won't start (https://ls1tech.com/forums/pcm-diagnostics-tuning/1687759-cranks-but-wont-start.html)

SuperC1 Nov 8, 2013 05:19 PM

Cranks but won't start
 
1 Attachment(s)
Changing things up a bit, decided to install a smaller boost friendly cam in my low comp 383. Just installed the new cam new lifters and new head gaskets. Got everything hooked up and turned the key and it just cranks, wont start. Checked for fuel, plugs were wet, put new ones in, checked for spark with an inline tester and its good, getting plenty of air, but no start. I believe the problem is in the tune any suggestions. File attached..

danieloneil01 Nov 8, 2013 08:25 PM

This is a FI setup?
MAF?

SuperC1 Nov 8, 2013 10:57 PM

FI
2 Bar SD
383ci
79lb inj
Dual walbro
42psi
Return style setup

danieloneil01 Nov 9, 2013 01:40 AM

Do you have any DTCs?

SuperC1 Nov 9, 2013 07:41 AM

No DTCs, pulled the intake to make sure everything was plugged in, and all grounds are connected. Cranks instantly with a shot of starter fluid.

dreww Nov 9, 2013 04:19 PM

Are u getting fuel injector pulse? Had a similar issue and no inj pulse. Was ign switch for me

SuperC1 Nov 9, 2013 08:43 PM

It's pulsing, plugs are def getting wet, so there is fuel there. Just not sure if it is enough or too much.

dreww Nov 10, 2013 08:59 AM

Must be too much fuel then....obviously a fuel issue if brake cleaner in intake allows a successful start. Don't really know where to look in tune for that...but idle fuel tables are a good start.

SuperC1 Nov 10, 2013 09:09 AM

I agree with you on that one Dreww, I'll start removing some fuel a little at a time. But I tried the flood clear deal with the pedal to the floor which should stop the fuel from coming in and it acted like it still didn't want to crank. It actually seems like it was closer to starting with the throttle closed.

SuperC1 Nov 19, 2013 01:31 PM

Ok so I reduced the the cranking VE in steps down to 40% and still no luck. I tried to increase it by 10% and no change. I logged the crank so I could view the data and I notice that the commanded afr constantly switches between 6.46 to 14.63 during cranking, is this normal? I'll post a copy of the log.

SuperC1 Nov 19, 2013 06:57 PM

3 Attachment(s)
I have scaled cranking VE, and cranking FA stage 1, and my commanded AFR has changed very little if any, logs attached..

gagliano7 Nov 20, 2013 06:51 AM

When you first start the car commanded afr is 3.63. I would post your tune so people can help.

SuperC1 Nov 20, 2013 07:33 AM


Originally Posted by gagliano7 (Post 17836477)
When you first start the car commanded afr is 3.63. I would post your tune so people can help.

Tune is posted in the first thread.

SuperC1 Nov 25, 2013 07:35 AM

Problem solved, it looks like 3 out of the 8 injectors had failed, replaced all eight and it fired right up. They all looked brand new, so I'm not sure what caused them to fail. But to make a long story short, there was fuel there, just not enough.


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