Engine stalling on heavy accelerations

69L48Z27

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If some how it was dumping way too much fuel it would stall too, but it would be a lot. Lean pop is a tell, when trouble shooting I try not to assume anything.
 

Wietse

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if you really want to keep the tunnel and street drive it, maybe you need to fabricate some sheetmetal baffles and install them in the intake reducing plenum volume and increasing air velocity.
Kind of defeats the purpose of using that high intake, or not?
 

BB BELLA

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Kind of defeats the purpose of using that high intake, or not?
on the track with a 3500 stall converter it might hurt,but on the street I doubt you'd notice it! motor is likely running through a full exhaust system so I imagine the tunnel is likely way over kill in it's airflow ability!sounds like he's married to it with the hood mods and likes the look so you just make the drivability work the best you can and don't worry about the time slips
 

HEMI-ITIS

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With a carb,I would fatten the pump shot and change primary air bleeds.I have no clue with EFI.

4.19.15 067.jpg
 

BSB67

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We’ve run TRs on pretty mild street applications and on a small block too. They run surprisingly well. Usually have to work at covering the lean hole at initial full hit, assuming everything else is right.

If it bogs and then accelerates, it’s not fuel delivery.
 

mouserider

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We’ve run TRs on pretty mild street applications and on a small block too. They run surprisingly well. Usually have to work at covering the lean hole at initial full hit, assuming everything else is right.

If it bogs and then accelerates, it’s not fuel delivery.
Yeah basically it’s 2 issues before and after acceleration, which happens either one of them or both, bogs before acceleration when I hit the pedal and stalls after I release the pedal. As I said it might be only first or only second issue or both. Now I went through EFI setup and found out that my throttle blades was not adjusted properly. Will give it a try later, but I doubt that’s the issue since that exact problem was on carburetors as well. If only they were also not properly tuned. I live in Cyprus, so no way to find anyone good with carbs.
 

mouserider

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ok its got even worse then before, it dives/stalls before almost every acceleration, then on park, it stalls AFTER anything above 2k+ RPM.
 

mouserider

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So here what it does on idle,



and here what is hapnning with fuel pressure (Holley says it should be 60 at all conditions)
 

Coop

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Basically trying to solve that problem for the last 3-4 month, all have started when we put indy tunnel ram, 2 holley 450 and Edelbrock Performer-Plus Cam 2192.
Since then problem still exist, however
we changed like 3 fuel pumps and 2 regulators
we rebuilt entire fuel line
we moved from holley carbs to Sniper EFI for dual quads
we put entirely new fuel system, high pressure regs, pump, filters
we moved to MSD with CD Box

It just not going away, if i accelerate slowly its ok, but if i floor it, its just feels like stalling for 1-2 sec and then it accelerates, sometime engine can completely shut down

We dont have vacuum gauge (ordered one) but via msd software it looks like 15.

What i also noticed, that when it stalling, fuel pressure also drops, but fuel pump working (and as i said, this was happening with 3 different fuel pumps and with both carbureted setup and EFI

im now thinking, that maybe its because of tunnel ram and inappropriate cam.

Thanks for advise.
Sounds like you have it figured out. I’m no expert but sumped fuel cell sounds like the next logical step. Fuel pressure drop you are observing is solid data. Problem persists despite changing the rest of the fuel system.
 

Carcinogen

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Check voltage at coil, if full voltage try different coil. Spark might not be strong enough to fire when cylinder pressure increases.

I had to use relay to battery because of old wire had too much resistance causing voltage loss.
 

Logan Hughes

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Did you replace the fuel pump pushrod? I had similar symptoms after my 440 rebuild and that proved to be the problem.
 

Old Sparky

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The sock in the tank is collapsing under high demand for fuel would be my guess.
 

Nxcoupe

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Thank you guys, will definitely go check all one by one. But today I also noticed another strange behavior. So car at park, I give it 3k+ rpm, keep it for 10-15 sec checking fuel pressure, all good. Second I release the pedal and rpm goes to idle it starts to stall. Tried like 5 times and every time it’s the same
Turn off decel fuel shut off (DFSO) or turn up how many seconds before it turns on.
 

Purepony

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Any intake leaks by chance ? My car stalled and did what your describing and I couldn’t figure it out until the oil puddle started leaking. I replaced my intake gasket and no more probs.
 

Sweet5ltr

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With the Sniper, you have an AFR reading and can datalog exactly what's happening during this event timeline.

The best tuning tool you can purchase right now is an AFR gauge setup. As another member mentioned, on a carbureted application you would likely increase the 'pump shot' with a larger accelerator pump discharge nozzle, and play around with pump cams.
 
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