Engine Foxbody idle/throttle issues

Okay.. so I had a thread open about these issues about 4 months ago, however, due to the diagnosing information I've learned (basic/advanced auto electricity class) I am redoing my thread. First things first, I have a 1992 Mustang 5.0 (2.3-5.0 swap) with flowmaster exhaust (no cats), I am 90% sure I have an aftermarket cam, 24lb injectors (and MAF), LMR CAI, GT40 Heads/Intake. Now, for my issues. With MAF plugged in, the car idles great. However, there is absolutely no throttle. Give it gas, it'll practically kill itself and bog out. Even while driving around town, it can't get out of its own way. When you LET OFF the gas (At idle), the RPM then snaps up before settling back down. With the MAF UNPLUGGED it idles like sh*t (Obviously) however, it revs, and accelerates like a DREAMMMM. Before someone pins the surging idle checklist, don't worry, I am familiar, and trying to work on it. First things first out of what I did, was run codes. KOEO got me code 32 (EVP sensor), and code 66 (I think this was the #, it was the MAF voltage). I was going to do KOER codes, but the car literally would not idle, even with MAF plugged in (weird). So, I went ahead with the hand I was dealt. First, I went after the code 32. Removed the EGR sensor, took the EVP sensor off of it (that is what it's called right?) then proceeded to spray out the EGR sensor with brake clean. Tested the plunger to make sure it freely moves, and all good there. So after scouring the forums, I found the test procedures for the sensor, and here are my results: (colors may be different, maybe my wires are dirty)

Pin 46, White/Red .6 Ohms
Pin 26, Black/White .4 Ohms
Pin 27, Black/Green .9 Ohms

I also tested the sensor itself, but I did not record my readings. I do remember they were in spec however. After doing these tests, I had to assume the sensor, and wires are good, so I put it back on (have yet to clear/rerun codes). Next up, was the MAF code. Following the test procedures for the MAF, here were the results I got.

Pin D, Pin 50 1.3 Ohms
Pin C, Pin 9 .3 Ohms
Pins C/D 0L
Pins A/B 0L
(All tests done with MAF connector unplugged)

Now, I dont believe the readings here are correct, but maybe someone could tell me if they are in spec. At this point, the sun had set, and it was time to retreat back into the house. I will go play with it more after work tomorrow, but since I have to wait anyways, I was hoping for some input from everyone here. Thanks y'all!
 
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Have you checked the ECU for bad capacitors or any burnt runs/traces?

Being the car has been swapped hopefully you have verified that the ECU harness is from. A 92/93 car as those are the only two years that will plug into a 92 car being the dash harness plugs into this harness and that connector is specific to those two years. From there you need the correct O2 harness (ato trans is different than manual) and any year injector harness from 87-93 will work.

What brand MAF do you currently have?
 
That's the thing about swaps, especially if you didn't do it yourself, so much missing info it's enough to drive you crazy if you let it.
 
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Have you checked the ECU for bad capacitors or any burnt runs/traces?

Being the car has been swapped hopefully you have verified that the ECU harness is from. A 92/93 car as those are the only two years that will plug into a 92 car being the dash harness plugs into this harness and that connector is specific to those two years. From there you need the correct O2 harness (ato trans is different than manual) and any year injector harness from 87-93 will work.

What brand MAF do you currently have?
The MAF is a BBK. I should have mentioned the swap was done like 3-4 years ago by me and my dad. It only started running like crap this past fall, and I even had my upgrades on it since the beginning of the summer. So it was running great, but something went bad. Just can’t pinpoint what it could possibly be. In my original post I stated it idled great with the MAF plugged in.. but now it won’t idle period either way. Keeps me from checking for any codes. But there isn’t a CEL anyways.
 
Have you checked the ECU for bad capacitors or any burnt runs/traces?

Being the car has been swapped hopefully you have verified that the ECU harness is from. A 92/93 car as those are the only two years that will plug into a 92 car being the dash harness plugs into this harness and that connector is specific to those two years. From there you need the correct O2 harness (ato trans is different than manual) and any year injector harness from 87-93 will work.

What brand MAF do you currently have?
Also, I haven’t checked the ecu for any internal damage.. however I did swap my ECU with one from the parts car 3-4 months ago, and the problem did not go away. But maybe I’ll double check on all that.
 
I will say that my money is on that BBK MAF. Pro-M or C&L are probably the two best aftermarket MAF's that are calibrated for larger injectors. You don't hear many folks raving about the BBK's. I ran a Pro-M Bullet calibrated for 24's for years until I stepped up to the 42's.
 
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Glad to hear you did swap with your dad.
I'd try clocking your bbk ma f , this is suppose to change the airflow or something like that.
I've heard other do it so maybe if it changes your issues then you can buy a different one.
 
I’ve tried clocking them in the past and haven’t had any luck, I’ll try it again tomorrow when I get it put back together. There’s been a nasty vacuum leak coming from somewhere towards my lower intake. My smoke machine couldn’t find it but that’s where it sounds like it’s coming from. I’m taking it apart down to there and I’m gonna put it back together and see if the leak disappears.
 
The MAF meter has to be plugged in to correctly test it. IIRC, the “ground” is a loop.

Doesn’t sound like a MAF issue to me by the way you describe it. Seems like low fuel pressure, or faulty Fuel regulator. Fuel pressure should be 39 psi.
I’ll put a gauge on it next chance I get.. still need to get the intake back on it and see if that vacuum leak is gone. I really just need the new regulator with the gauge on it so I can see it at all times. What’s the proper way to test the fuel pressure?
 
The Ford MAF has 2 grounds, (sorta), and no 5v ref.

-you have the battery voltage wire
-Signal return wire
-A signal ground
-A chassis ground wire

the 2 ground wires connect to each other through the MAF. So if you unplug the MAF to do the test, you disconnect the signal ground.
The MAF must remain plugged in.
BF3178DD-C92C-479E-B6F1-5580C9760922.jpeg
 
I’ll put a gauge on it next chance I get.. still need to get the intake back on it and see if that vacuum leak is gone. I really just need the new regulator with the gauge on it so I can see it at all times. What’s the proper way to test the fuel pressure?
With the vacuum line removed (and plugged)
You should also test under engine load/ driving, but since your issue is present at idle that would be fine for now.