MAP Spikes From Throttle Blips, Rockers, Lifters, Check Out This Log Picture, NUTS!!!

[GNVYUS 1]

New engine, 900 miles total, all new parts but this is driving me nuts, check out this picture.

If you're at 0% TPS and then do a somewhat or fast throttle blip it will cause a crazy spike in MAP and KPA like -8" to 13psi in milliseconds. This spike then warrants a crazy fuel dump, though there's no real boost or compression, the car then floods out and either will stall or drown to 440rpm and come back staggering. You have to creep into the throttle to drive it but it's not safe.

I thought it might be a cam sensor error, then we thought maybe a lean backfire etc but what adds up to a crazy spike from vacuum to 13psi in milliseconds?

Anyone seen this before?
Rockers out of whack?
Lifters not pumping?
Cam degreed all jacked?

I'm leaning now towards mechanical synchronization that's causing a spike in the intake like a backfire. I'll have the whole valvetrain looked over, rockers, lifters and push rods inspected but damn, really bummed, cars not safe to drive and this years another year of 20 miles of driving.

 

[CS99]

Pretty sure it's in the tune. I have holley. There are fuel enrichment tables such as fuel vs tps. Sounds like you may have to back of the fuel in those areas.

 

[Chuck Leeper]

MAP reads KOEO?

 

[GNVYUS 1]

Looking like lean backfires that we are trying to get a handle on, car will go a little fat on Accel pump like normal but then sometimes after this it'll lean out and jump to 15:1 AFR and worse.

This lean backfire is causing a MAP spike that then triggers fuel from 13psi MAP table and it floods out.

I cleaned up some choppyness on the throttle blips by going 13.5 AFR at idle and pulling some fuel in the Accel TPS tip in but these lean spots around 2000rpm etc are being a pain.

 

[TurboBob]

hit me up on email (and eric also) with a copy of the tune and the logs.