95 LT1 383 24x conversion 0411 no start

[Christian GM]

hello to all guys
I started my own restoration project back in 2008. I fired up 30 seconds the engine in 2011 with basetune file attached
the, for several reason the project sat in my garage for years untouched. it is a 80 TA with a 4L60E and 95 LT1 with LS1 Eficonnection system
it's 383 with GMPP LT4 hot cam and rockers, head LT4 ported with bigger valves bu Golen engine. Matching intake manifold. DBW throttle body, with 2 blades.
red skynny Ford injectors.custom intake not yet totally done with LS1 MAF, fuel pressure reg adjusted to 58.
one week ago I try to fired up the engine again, and it started for about 1 minutes. then dies and no way to start again ... looks to rich.
so, yesterday I cahnged the 7 years old fuel on the tank, fuel filter, and 8 spark plug ACD #3 gap to .45 according to Chad @ Golen engine.
I checked the tune (I read dozen of discussion here on the board), I was not sure on the firing order, so I checked the harnes I put all back like LS1 to match wire and schematics and changed the firing order on the tune. I changed the fuel injector data with Greg ones (I have all the DVD and books)
but no way, no starts. I need to decrease MAF value of about 40% in order to have the engine starts but it's not running on 8 cylinder, very bad... missfire does not read anyway... so no idea what cylinders is not working according to flame and bang on the exhaust there is again too much un burned fuel around.
so now I'm tired and out of idea.
I have the feeling I'm not seeing something obviously wrong around
any tip will be higly appreciated
time to send the car out of the garage to the body shop!
thank you so much
bye

[anniversaryss]

I wish I was home to look at this.
You switched around the harness for the injectors?
Firing order in the pcm doesnt matter other than misfire.

[anniversaryss]

What do you mean by custom intake not done? Ant vac leaks?

[Christian GM]

I wish I was home to look at this.
You switched around the harness for the injectors?
Firing order in the pcm doesnt matter other than misfire.

seriusly? I read a couple of post on the forum... you can do with harnes OR with firning order, NOT Both or Nothing...
I wired back to LS1 firing order and changed the calibration firing... nothing too hard to do, I need to change it back to LT1 firing on the harness?

[Christian GM]

What do you mean by custom intake not done? Ant vac leaks?

I mean the filter and duct BEFORE the MAF are not the definitive ones...this could affect MAF calibration, but nothing more...

[anniversaryss]

I deleted a few comments to clear space up here. So to clarify ..
2 & 3, 4 & 7 must be swapped in the harness for the coil packs and injectors.

Your injector bank assignments are correct.

I'm sure some more trained eyes can see more than I see but you seem to have a very high MAP reading. Also I'm assuming your ECT temps are low and your commanding 10.4 afr but your oxygen sensors are pegged lean.
Do you happen to have a wideband to clarify reasdings?
Anyway you may have a vac leak?

Also I havent went through the full tune but bc your using a vac regulated fpr your Injector IFR should be the same straight across as should your offsets.

But I would check to see if you have all your wiring all set and then check out any large vac leaks maybe.

[Christian GM]

I deleted a few comments to clear space up here. So to clarify ..
2 & 3, 4 & 7 must be swapped in the harness for the coil packs and injectors.

Your injector bank assignments are correct.

I'm sure some more trained eyes can see more than I see but you seem to have a very high MAP reading. Also I'm assuming your ECT temps are low and your commanding 10.4 afr but your oxygen sensors are pegged lean.
Do you happen to have a wideband to clarify reasdings?
Anyway you may have a vac leak?

Also I havent went through the full tune but bc your using a vac regulated fpr your Injector IFR should be the same straight across as should your offsets.

But I would check to see if you have all your wiring all set and then check out any large vac leaks maybe.

hello
I checked all 8 inj and coils, correctly wired per LT1 firing order
I'm doing it in my garage at nearly 13?C ambient temperature.
everything else looks ok to me but the engine does not starts - and often big bang sound from exhaust (unburn fuel?) and some small flames
I try also this tune from repositoty (not too many too chose) but no way

[Christian GM]

attached another tune and some of the many logs I did...
I started decreasing MAF values due to too much fuel to me ...
but I don't find the sweet point to start the engine
it's driving me nuts...

[Christian GM]

let's go one step back..
attached the original file from PCM4Less dated 2009/2010 or so
later I changed injectors to ford red skynny
with that file car always starts (30 seconds) and die. since no wheels on it, I can't take out of the garage so I didn't care to much
I put the wheels, 2 weeks ago. start the engine, drive gear, out of the garage. one minutes or so, no way to start it again.
fueled spark lugs, really wet and dark.
so last saturday I changed old fuel on the tank, fuel filter, new plugs, but no way to start engine angain.
always backfire on the exhaust and RARELY on intake...
no way to start regardless of what calibration I use...

what is going wrong???

[Christian GM]

just checked compression on 6 cylinders to look for too tight pushrod
all at 200 PSI, so compression is not an issue.
no fuel leak from fuel regulator MAP hose
the engine is backfiring during crank. from exhaust
like if it's firing the wrong cylinder.
I see crank RPM with scan tool, but MAYBE the ecm is not seeing cylinder one position, so it does not have the correct reference for firing.
how we can check it out?

[Christian GM]

evening update.
I fixed the backfiring, on the coils BOTH signal and negative reference must be swapped from side to side.
I'm looking to see the MAP...
see you tomorrow

[Christian GM]

It's is alive and running.
During the weekend I will do some better idle and low rpm adjustment.

[anniversaryss]

Sweeeeet