Slight throttle dies
 

Ok fellas, so here's the issue. And before you say it, yes I have researched and tried diagnosing.
This happens when:
Partial throttle is applied
In any gear, At rpm:
Afr - - -(dashes) out lean
Dies at idle
Face plants driving

If I baby touch the throttle its fine and drivable..ish except up hill not enough air flow/power:
- 1.6v to ~3.9+v

At ~4.5v partial throttle that's when dash out lean Afr hits
During idling it WILL cause engine to die.
While driving it will cause power loss and nose dive
When I press just past "dead zone" throttle, 4.5v half to full throttle, afr jumps back up to normal operation

So I'd say
0 to 10% throttle input gives normal afr

~15 to 25% is the "dead zone"

~30 to 100% throttle input gives normal afr
If that makes any more since.

I have checked for any possible vacuum leaks, all resolved.
Timing. No change.
Swapped around afm, tps, barometric pressure sensor. No change.
Put my rtek 2.1 to factory settings. No change.
Swapped around injectors. No change.

If any other info is need, please ask.
This issue makes it hell to drive slow in residential, or go from a stop without spinning wheels.

Thanks, Brendan

Thread Copied..and now shows up in the RTEK Section so you can get help there too.
Good luck to ya.
STYX (MOD)

Do you have a stock ecu to swap in to check?

Haven't swapped ecus yet, will try that tomorrow.

Was thinking maybe poor fuel pressure, but that affect higher rpms and not lower, right?

Turbo or na

Also when you give it partial throttle i wonder if it somehow thinks its in decel mode and is cutting fuel to 1 rotor... i dunnno

disconnect the TPS and retry

Sorry should've specified specs

86 frame 88 turbo swap
Stock ports all emissions removed
Bac valve installed, not plugged in
(Not a leak source, I've checked)
550s prime and sec for now
Modded tb
60-1 t04e .82 ar exhaust 3" outlet
Running +/- 5 psi for breakin period
2.5" tubing and large fmic
Stock coils and plugs
Avcr ebc
Rtek 2.1
Apexi neo (only for system monitoring)
Read rumors on here that they sometimes cause issues even being installed. May remove for testing.
Aem wb afr


I will disconnect tps and try swapping ecu at different interval.

What will disconnecting the tps do or show? Will it even start or run?

ditch the neo, if it isnt set properly it will only cause issues

Probably will for troubleshooting. But issues came after neo install. Actually years later.
About to go fly now, but will test first thing tomorrow.

Crap video, but best I could do at 11pm. Hopefully it can shed some more light on the issue. I'll take a better one if needed. Gonna test tomorrow.

Thanks

Disconnected while idling. Died. Started without tps. Wouldn't hold idle. Still had dead zone.
Not sure what that was testing.. But plugging it back in lol

Ecu swap next. Then neo removal.

Ecu swap. No change.
Neo removal. No change.
:/

simple, the TPS is what controls decel rear rotor cut and decel full fuel cut. it is a process of elimination.

sounds like you have a faulty injector ground or a severe lack of fuel pressure.

I gotcha! Ya and I'm starting to think fuel psi as well. If I slowly let off the throttle that "dead zone" almost disappears. May be a hack job. But thinking of using a vice grib to slightly increase pressure by making the return side a little more restricted. Thoughts? BTW, this will NOT be permanent. Just for testing.

that would only work if the regulator is stuck open and allowing pressure to bleed off. if the pump is weak or there is a bypassing leak inside the tank then that won't really accomplish much. you can usually rent a pressure tester from a generic auto parts store.

Started cheap tonight by getting a new fuel filter. Did the $1 hooker trick and put my mouth on it and blew lol
Old one was definitely restrictive compared to the new one. Gonna go out tonight and gather info :D

Boost leak or vac leak between turbo and throttle body...

AFM can't read the extra air drawn in as the throttle is slightly opened as it sucks air elsewhere.

Once the turbo starts spooling it draws air through the AFM and sorts itself out..

Probably runs a bit rich on boost too and a bit lean on idle too.

If it was fuel filter/pump/pressure it would hate any kind of load.

Or maybe the ECU isn't giving that extra squirt of fuel as the throttle is pressed as an accelerator pump does on a carby.

Also check and double check ignition timing as per factory specs as retarded ign timing will do this too.

a large vacuum leak could do it but i'd be pretty surprised that the ECU didn't cut off the pump once started and that the car wouldn't just continually stall versus idle. but i guess it really depends where the leak is and whether it is able to act as a flapper valve with enough air movement.

Pulled the fuel pump out. Inside looks either rusted or just dirty. Aaaaand the pump sock was destroyed. Looks like the pump ate it. Soooooo. Got an aeromotive 340 on the way, but gonna try this one again with a new sock and see how it does. Plus I'm gonna try to do the 12v pump rewire.

a rewire is a good idea for any turbo car, sounds skeptical that a new sock will fix the pump though.

I don't disagree, bit thought it might be worth a shot. Jury rigged some crap as a sock to prevent large contaminants from getting in. I think the pump is just shot. Between eating the old sock and more than likely because it sat in old fuel its probably just done. New pump should be in Wednesday. I'll report back then.

Just installed a aeromotive 340lph. No a little tiny bit smoother. But overall, no change. Maybe a bad fpr??? Idk. I'm at wits end :(

have you checked the injector ground on the main engine harness?

Ya, good ground. No paint under it, no rust.

checked the pump voltage yet?

Voltages normal. Idk man. Seriously about to just give up and drive it like this.

well it sounds like a serious pump volume issue, i'd still check the pressure if possible.

next thing that comes to mind is shorting out TPS wiring, maybe the wires got pinched on the engine somewhere. after that would be injector grounding through the ECU and the supply voltage through the black/yellow wires to the injectors.

you can add additional grounds to the block where the injector ground is, or to the other end at the ECU. you can monitor the black/yellow circuit by finding something accessible on the engine with that same power feed via the factory wiring diagram. you can also check the TPS voltages with your Rtek i believe with an oscilloscope reading to see if it is spiking or reading abnormally glitchy. while you are at that i would also draw up an o-scope reading of the AFM reading. you have a handy diagnostic tool with the Rtek 2.x so you should be using it.

another problem is swapped engines using the stock n/a engine harness on a turbo ECU, there is a power steering sensor wire that feeds into the knock circuit that will cause all sorts of strangeness, but generally this is only an issue while turning and also generally only affects ignition timing and not fuel.

all of that failing to come up with any result it may be time for a new engine harness and flush the injectors(unless you have the time to test the whole harness and cross continuity check all wires which results in a few thousand ohm checks and is rather time consuming, frayed wires rubbing together in a harness can be a nightmare to track down).

The injector ground is located on top of the engine. Is the above comment in response to the ground you checked or some other ground?

So i just read that you changed the fuel filter BEFORE you pulled the pump and it ate the sock. Is it possible the fuel filter could be clogged with said sock, or any other debris that got through?

Well did some shade tree mechanic testing yesterday.. Put a pair of vice grips on the return line, not completely pintched. But enough to make some good back pressure. Just that cured about 80% of the issue. Reason I decided to go this route was because I removed the vaccuum line on the fpr, which I imagined would cause high psi all the time. No change. What I did notice though is that the vac nipple on the fpr had a drip of fuel. Bad diaphragm. So, now I have a tomie fpr on the way. We'll see how it does

Ok... Sooo for anyone that was wondering wtf.. I am stupid. I openly and humbly admit it. The issue, and only issue(s) was that I put injector harnesses in the wrong spots.. I can't remember which ones I had where. But the contributing factor was looking at the wrong diagram in the fsm. Runs clean and perfect now. No dead zone. No backfire no stststudder
Lessons learned:
Double check work.
Trust advice of others
Double check instructions
Repeat until desired results

To all those that offered help and advice. Thank you so much.

-REtard

Congrats on getting it figured out

I did the same thing on my first swap.
Funny the guy next door was a War Vet and when I'd start the car it would Backfire a big Cannon BOOOOOMM..through the Corksport single..lol!
I betcha I took him back a couple years!