Engine The Bug that can't be found

Drop5oh

Member
Apr 20, 2022
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I Have 92 Gt Stock 302 ( aod ) minus egr delete and smog delete. Car was running fine every since I've bought it road trips and all. Coming home from work one night on the highway it started with a miss kind of like would loose power than immediately come back almost like a bad spark plug or wire problem. It happens at idle, cruise, and highway speed like it makes the car jerk then clear out. Spark plugs and wires were fairly new but I still changed them also changed new distributor and tfi also ignition coil. New mass air and O2 sensors New ignition switch and fuel pump and fuel filter. New injectors and new harness. Did pull computer and fund the normal compactor leaking sent to get rebuilt and tested (Fox resto) also replaced relay above computer. Car is throwing no engine codes on my obd scanner but the miss is still their. I've checked tps setting at .98 Please help me guys I'm running out of bucks could my bap sensor be bad it's not running no different when I unplugged it?
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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Car is throwing no engine codes on my obd scanner
What scanner are you using?
minus egr delete and smog delete.
does this mean the egr and smog are still there??
But seriously, I would be looking at a ignition connection problem like the ten pin connectors or 'salt and pepper shakers', everything (nearly) that monitor or receive a 'pulse' goes through those. Take em apart, clean em up, put some of that electrical goop in there and push em back together.
That's what I would start with, so it's prolly wrong. :shrug:
 

Drop5oh

Member
Apr 20, 2022
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What scanner are you using?

does this mean the egr and smog are still there??
But seriously, I would be looking at a ignition connection problem like the ten pin connectors or 'salt and pepper shakers', everything (nearly) that monitor or receive a 'pulse' goes through those. Take em apart, clean em up, put some of that electrical goop in there and push em back together.
That's what I would start with, so it's prolly wrong. :shrug:
Using standard OBD1 Ford tester. Also that's the only thing I've removed from my car is smog and egr. Doubt it's related to either one of those I've drove a few thousand miles since those delete with zero problems. I will check over all electrical again. But even at idle I'm grabbing almost everything far as harness and connectors and relays trying to shake or move things to create the problem. It's like it almost just randomly does it when it wants to. I've replaced my ignition switch and with new wire kit for ignition switch
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
39,486
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Sounds ignition related, but you've replaced all the components I would suggest.

PIP is the only one i would still question as replacement distributors have been known to have issues with the PIP and shutter wheel. They are being made incorrectly.

Do you still have your original distributor? You could try transfering a new PIP and the TFI over to that and see if it makes any difference.
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
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A smog and EGR delete car will not show code 11’s to the KOEO and KOER tests (without reprogramming).
Literally taken, “no codes” is an indicator of problems, not the lack of them.
So, are you getting code 11 or no codes?
 
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CAMTWO1070

Active Member
Dec 17, 2021
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I'd try replacing the EEC and Fuelpump relays and looking at the EEC grounding points. If you get new relays get ones w/diode protection.. These are Bosch style but Ford started putting diodes in their relays starting in 1995 in the pic below it.

IMG_20211216_232425.jpg

Screenshot 2021-12-19 165625.jpg


Mine was doing something similar to what you described and happened a couple of times in separate situations.

The very first time it happened it was the adapter that adapts a 4 wire MAF to a 6 Wire..One of the wires wasnt getting a good connection inside the plug so I tightened up the female ends and put some di-electric grease on the plug to seal it.

When it happened again and I checked the plug it was good then someone suggested putting a plate so the highway air doesnt mess with the MAF...

So it turned out that my MAF sensor was getting an extra blast of air being unshrouded and that extra burst was enough to make the engine cut out then come back when it cooled the heated wire down too much...

It gave a lurch jerk like I had a leaky sparkwire..The rpm's would spike up kinda too when it was in no-mans land..

Another thing to note is that none of the problems threw a code either...

I put an aluminum blocker plate and haven't had an issue since.........

Good Luck

IMG_20210927_183244.jpg
 

CAMTWO1070

Active Member
Dec 17, 2021
147
43
38
I hate when I forget about other situations until after I push the button....LOL

I went with a friend to buy a convertible Mustang in NC and he decided to drive it home...Car was cutting out sparatically so he pulled over and we stuck it on the trailer and towed it the rest of the way...

When we got home the column looked abnormally chipped up so we called the old owner and he said the chips came from his keyring that had 15 keys and a Huge 3/8" thick stainless steel Shamrock attached to it...

Turned out that the heavy keychain coupled to age made the ignition switch on the column go bad;-..So bad the switch came out in 2 pieces and was only held in with 1 tab..Put a new ignition switch and the car ran beautifully.........

Whats funny is when we were cleaning the car out we found another Shamrock too...Its really heavy.....LOL\

Good Luck finding the gremlin..

1510288148492.jpg
 

Drop5oh

Member
Apr 20, 2022
7
1
13
I'd try replacing the EEC and Fuelpump relays and looking at the EEC grounding points. If you get new relays get ones w/diode protection.. These are Bosch style but Ford started putting diodes in their relays starting in 1995 in the pic below it.

IMG_20211216_232425.jpg

Screenshot 2021-12-19 165625.jpg


Mine was doing something similar to what you described and happened a couple of times in separate situations.

The very first time it happened it was the adapter that adapts a 4 wire MAF to a 6 Wire..One of the wires wasnt getting a good connection inside the plug so I tightened up the female ends and put some di-electric grease on the plug to seal it.

When it happened again and I checked the plug it was good then someone suggested putting a plate so the highway air doesnt mess with the MAF...

So it turned out that my MAF sensor was getting an extra blast of air being unshrouded and that extra burst was enough to make the engine cut out then come back when it cooled the heated wire down too much...

It gave a lurch jerk like I had a leaky sparkwire..The rpm's would spike up kinda too when it was in no-mans land..

Another thing to note is that none of the problems threw a code either...

I put an aluminum blocker plate and haven't had an issue since.........

Good Luck

IMG_20210927_183244.jpg
Thanx for the comment man. I've replaced both the fuel pump and eec relay when ECU was rebuilt. I've chased the problem down to a short in my tfi connector possibly loose pin. I've ordered the new kit with pigtail from Lmr also ordered a new spout with connector and pigtail. I can pull on that harness at the connector and whole car just about dies and comes back sometime shuts all the way off. Hate I replaced all those parts and it being something that simple but oh well I guess all new everything isn't all that bad
 

Drop5oh

Member
Apr 20, 2022
7
1
13
I hate when I forget about other situations until after I push the button....LOL

I went with a friend to buy a convertible Mustang in NC and he decided to drive it home...Car was cutting out sparatically so he pulled over and we stuck it on the trailer and towed it the rest of the way...

When we got home the column looked abnormally chipped up so we called the old owner and he said the chips came from his keyring that had 15 keys and a Huge 3/8" thick stainless steel Shamrock attached to it...

Turned out that the heavy keychain coupled to age made the ignition switch on the column go bad;-..So bad the switch came out in 2 pieces and was only held in with 1 tab..Put a new ignition switch and the car ran beautifully.........

Whats funny is when we were cleaning the car out we found another Shamrock too...Its really heavy.....LOL\

Good Luck finding the gremlin..

1510288148492.jpg
Lol I love q good fox story glad you guys figured it out. I just chased my problem down to a short at the tfi connector I can pull on that part of the harness at spout and connector and whole car shuts off almost. I'm go ahead and change tfi to although it's brand new with new distributor
 

Drop5oh

Member
Apr 20, 2022
7
1
13
I'd try replacing the EEC and Fuelpump relays and looking at the EEC grounding points. If you get new relays get ones w/diode protection.. These are Bosch style but Ford started putting diodes in their relays starting in 1995 in the pic below it.

IMG_20211216_232425.jpg

Screenshot 2021-12-19 165625.jpg


Mine was doing something similar to what you described and happened a couple of times in separate situations.

The very first time it happened it was the adapter that adapts a 4 wire MAF to a 6 Wire..One of the wires wasnt getting a good connection inside the plug so I tightened up the female ends and put some di-electric grease on the plug to seal it.

When it happened again and I checked the plug it was good then someone suggested putting a plate so the highway air doesnt mess with the MAF...

So it turned out that my MAF sensor was getting an extra blast of air being unshrouded and that extra burst was enough to make the engine cut out then come back when it cooled the heated wire down too much...

It gave a lurch jerk like I had a leaky sparkwire..The rpm's would spike up kinda too when it was in no-mans land..

Another thing to note is that none of the problems threw a code either...

I put an aluminum blocker plate and haven't had an issue since.........

Good Luck

IMG_20210927_183244.jpg
Good find on that one I probably would have took a life time searching that one down. Mine turned out to be a short at the tfi connector or spout connector I can pull on that harness rite at distributor and car almost shuts off I've ordered all new connector with bigger gauge wires and new spout with pigtail I'm replace that tfi although it's new there known for being faulty out the box
 

Drop5oh

Member
Apr 20, 2022
7
1
13
This is not going to be an easy fix, you will need to monitor the fuel pressure while driving and check electrical connections in the ignition systems.
Found the problem at the tfi connector and or spout connector I can pull on that harness at the connector and car almost completely dies. I ordered a new connector with bigger gauge wires and new spout with pigtail I'm going to replace tfi as well
 

CAMTWO1070

Active Member
Dec 17, 2021
147
43
38
Good find on that one I probably would have took a life time searching that one down. Mine turned out to be a short at the tfi connector or spout connector I can pull on that harness rite at distributor and car almost shuts off I've ordered all new connector with bigger gauge wires and new spout with pigtail I'm replace that tfi although it's new there known for being faulty out the box
Very nice....

One thing to check is the resistance on the IDM circuit wire...If you get 0.00 and have a manual trans w/ non ccd TFI you need to install a 22kohm resistor on the wire coming from pin #4 on the ECU plug to pin #2 on the TFI plug and the negative side of the coil too...

IMG_20221023_145334.jpg
Screenshot 2022-10-24 123201.jpg


What most dont know is that automatic trans cars give signals to the ECU through the IDM circuit and the TFI has a Computer Controlled Dwell andalso built into the CCD type TFI module is the 22kohm resistor.

If you try running CCD TFI on a stickshift conversion things get wacky usually after 30-60 mins of cruising as the computer cant adjust dwell..
 

CAMTWO1070

Active Member
Dec 17, 2021
147
43
38
Very nice....

One thing to check is the resistance on the IDM circuit wire...If you get 0.00 and have a manual trans w/ non ccd TFI you need to install a 22kohm resistor on the wire coming from pin #4 on the ECU plug to pin #2 on the TFI plug and the negative side of the coil too...

IMG_20221023_145334.jpg
Screenshot 2022-10-24 123201.jpg


What most dont know is that automatic trans cars give signals to the ECU through the IDM circuit and the TFI has a Computer Controlled Dwell andalso built into the CCD type TFI module is the 22kohm resistor.

If you try running CCD TFI on a stickshift conversion things get wacky usually after 30-60 mins of cruising as the computer cant adjust dwell and if you dont have the 22k resistor wired in by the ECU connector coming from pin#4 you'll get sensor signal problems...