smokimon001

It is 88 10th ae, pretty much stock, with air bypass solenoid deleted, after market bov, racing beat down-pipe and exhaust. 90% of the vacuum lines were replaced, so the vacuum leak is out of the question, fuel injectors r checked and cleaned, all spark plugs have proper sparks, new throttle temp sensor, new maf. Car starts and run every time, compression check with warm engine at 104, 101, 97 psi front and 90, 90, 91 psi rear. I “T” the primary and secondary injectors signal wire from ecu and connect to a testing light, found out there is never signal being send out for secondary injectors from ecu, even during road test pass 3800 rpm.
The problem I am having here is, fuel cuts on me whenever I quick tap on the gas peddle, during idle or driving at any rpm, if I gentle on gas, it can gradually goes up to 7k, both idle or on the road. I also unplug the pressure sensor(near passenger side strut tower), it makes no difference.
Do I haven bad ecu? Bad pressure sensor or something else.
Thank u for ur time!

Aaron Cake

iTrader: (1)

Your TPS is bad or unplugged.

smokimon001

Tested the tps, 1.5v to start with, went up to 4.95v when the tps Rod was fully extended, I believe the throttle plate is not fully opened when the tps Rod is fully extended, since the gas paddle is only about 40% down when I reach the 4.95v(tps rod fully extended). Should I adjust the tps to 1v to begin with?
what is a fully functional tps test result is like?

smokimon001

First pic is ur post from 17 years ago, let’s me try these procedures first.

smokimon001

Fuel pressure won’t pass 30 psi when I rev up, it stays around 30psi, fuel pressure suppose increase as I increase throttle?

smokimon001

Fuel pressure drops about 2 psi whenever I rev, back to 30 psi when I let go of the throttle. Then I pinch the fuel return line coming out from the fuel regulator to simulate a working fuel regulator, fuel pressure went up to 38 psi, then I tried to fast throttle with the fuel retuned line pinched, the fuel cut problem still exist, there’s suction from the vacuum hose to the regulator, and suction decreases as I throttle, I don’t understand why the fuel pressure drop when I throttle, even with a bad fuel regulator, I am almost certain I have a bad fuel regulator. What u guys think?

And i I tried to adjust the tps, with three methods,
1. Using two DMM with the green connector, with engine idling, one DMM shows 0 volt and ones shows 12 volts.
2.Then I tried the omh method, clockwise 3 full turn to make it 940 omh, but then it gives me rough idle, counter-clockwise 3 turns back to 847 omh, idle back to smooth.
3. Pinned the top left connector with positive needle from DMM and place negative DMM needle to the battery negative terminal, it gives me 1.24v reading, If I adjust to 1 volt, it gives me rough idle again.

Do do I have a bad tps?

Tyrannosaurus Wrex

Following on this, my 88 GXL is having the same issue where once its adjusted to 1 volt when back-probing the TPS, and the idle wants to hunt around, when it cycles down the entire car shakes and feels like it wants to die before going back up to 1.1k rpm, hopefully a new tps would fix this issue as if I turn the AC on, the idle stays perfectly solid at 1.1k rpm

smokimon001

I had an 86 gxl, idle won’t hold unless I turned ac on, I think I adjusted the throttle to fix the issue, been a while don’t remember what exactly I did. It wasn’t the tps.
I bought an 87 jdm turbo II ecu for my 10th ae, it didn’t fix my issue ideal perfectly fine, but it runs lean.
I tired to smoke the tires, but when I drop the clutch around 4K, the rpm doesn’t hold and went down to idle. Unplug the vacuum hose to pressure/boost sensor, makes no difference.
I unplug the vacuum hose to the FPR, fuel pressure run up to 34 psi from 30, I guess the FPR works.

KingCobraV9

iTrader: (2)

Know it sounds dumb but. Have you changed your spark plugs as of late? I once had a problem I was SURE was a fuel cut. Turned out to be burnt up old fouled plugs.

smokimon001

They r good used plugs from my good running FD. I can rev the FC all the way up 7k if I am gentle with the gas paddle.
All 4 plugs has decent sparks when I pull them out to test with the FC.
I will order a set of new plugs to try out. I’m running out of ideas.
what prevents the ecu from sending out signals to secondary after 3800 rpm? I am having this issue as well when I test drive on the road, while slowly rev up past 3800.

smokimon001

Boost went from vacuum to -10 when I gently gas, it past 0 once I rapidly gas, but then gas cuts off, if I hold the gas paddle it stays at 0 but it would Idle really rough.
Boost is not be able to buildup.

smokimon001

It was the MAF, replaced with my na maf, it runs fine now, gonna get a n318.