LQ4 No Start - Vacuum?

[BigMc]

Got an issue with my LQ4 swap into a 91 Camaro.

2001 LQ4
LS6 Intake Manifold w/ Amazon 92mm TB
Sloppy Mechanic Cam
Headers
Wideband

I built this car last year and it ran fine. I?m self (YouTube) learning how to tune it. It probably had 1000 miles on it until the end of last summer. I was pushing it hard and suddenly thought I had a flat tire, so I pulled over into a parking lot. No flat. Tried to start the car and it wouldn?t start. Tried a few times and then heard a ?pop? from the engine bay. When checked, I found the rubber caps used to plug the open ports on the throttle body blown off and had to replace them. Had it towed and it?s basically sat all winter. Now, I?m trying to figure this out and get it back on the road.

I kept the same tune on it. It will barely fire then die (almost like VATS but VATS is turned off). I can try to give it throttle and it will try to sputter for a little while and die while I?m pumping gas. I can?t hardly get it to run to get a scan on it. No codes. I changed the CAM sensor and Crank sensor just guessing it could be a timing issue. No joy. I finally got it to run for just a minute. The only difference I can see in it from scans when it was running before, is that the MAP seems to be really high and doesn?t drop at start up.

I?m going to check tonight with a separate vacuum gauge. I can?t get it to run long enough to spray starter fluid around the intake.

I?m really stumped why this thing won?t run now. Before I start taking parts off the motor, I thought I would ask for your help on any ideas. Appreciate any help I can get.
I?ll attach a copy of my tune, a scan taken before the issue, and as much of a scan as I have been able to take recently.

Thanks

[horsepowerguru427]

Basic checks.
compression test
Leak down test
fuel pressure test
pull the valve covers and check springs

Tunes dont just go bad in the middle of a run. If you blew the caps out of the intake id suspect a backfire?

[twenglish1]

As mentioned above, check the obvious stuff first if you had it running before, blown off hoses, fouled plugs, your TPS is also reading 0.8%, this might seem insignificant but it will cause issues, especially at idle. But also how have you been tuning this? It is not in any correct configuration to be tuning either the MAF or VE and i see adjustments have been made to both. If you have been making adjustments to the VE without disabling the MAF it is wrong, same with adjusting the MAF, it needs to be set to exclusively use the MAF before adjustments can be made, and with fuel trims still enabled you should have been using the trims and not the wideband.

[bk2life]

PE is still set to be delayed to 5500 rpms, with an odd enrichment afr.

But, as those have stated above.
tunes dont die.
Engines do.
Check fuel pressure first.
will it run with carb spray in the intake?
is battery fully charged?
This is mechanical, not tune related, but, once you get it running again, that tune needs help.

[Alvin]

IAC is maxed out meaning it cannot allow enough air in for it to idle..

It looks rich which is going to make that situation worse.

TPS is bouncing + 0.4v to 0.8 occasionally. Usually this is where all idle learns/trims/etc stop. If it thinks you are driving becuse that amazon throttle body is sloppy and showing + TPS while not on the gas it will not try to idle.

[horsepowerguru427]

IAC is maxed out meaning it cannot allow enough air in for it to idle..

It looks rich which is going to make that situation worse.

TPS is bouncing + 0.4v to 0.8 occasionally. Usually this is where all idle learns/trims/etc stop. If it thinks you are driving becuse that amazon throttle body is sloppy and showing + TPS while not on the gas it will not try to idle.

Ive been fighting this exact same thing on a "VELOCITY" 102mm that was from the previous owner on my trans am. Talk about a PITA! lol I had to step the IAC passage up a bit and it helped the situation. Along with a lot of cold starts and IAC step logging. It idles now...lol

Ill be going Nick Williams or Motion ICON sometime.

[twenglish1]

I had issues with my no name amazon 92mm, ported the IAC passages, ovaled holes for the TPS, so i could get the voltage in the right range and still set the blade position for idle, also had to drill a small hole in the blade, IAC counts are right where they should be now and it idles! A Nick Williams has been on the list

[horsepowerguru427]

I had issues with my no name amazon 92mm, ported the IAC passages, ovaled holes for the TPS, so i could get the voltage in the right range and still set the blade position for idle, also had to drill a small hole in the blade, IAC counts are right where they should be now and it idles! A Nick Williams has been on the list

Im just happy i know enough to hack my way around getting a good quality one by doing the same things you mentioned lol I found my TPS return spring was broken and i changed it the other day. Damn things went from idling decent to being at 6% throttle at "idle" Get voltage low enough to reset it, Start tuning again