Engine Running outa ideas

[Aoneill5.0]

Ok

So
Lookin for advice.

89 GT 5.0 Edelbrock intake (all I know Mod wise)

Bought Ford Code reader
Got a 23 TPS is all for now
Also 98 ON the KOEO test.

Car works ok
Pulls hard
Needs a set of rear clutches (1 wheel spin)
Idle surges a bit.
Fuel pump goes 2-3 Seconds then off at KO
Any away

My main issues is that she won’t start sometimes after running for 30 mins.

Cranks OK
won’t fire up.

If I disconnect Bat for 5 mins (something clears)
Car fires right up.

I have not done the idle Surge/start checklist yet as I dont think I’ll find anything obvious.

Looked for vacuum leaks
Changed CTS/Coolant sender and TFI so far

Likely put a new TPS on as well..

Car has Cold intake
MAF removed (heard that’s OK with the intake that’s on it now..

Thanks for reading folks

Just looking for new places to look..

 

[Dan02gt]

If it’s a ‘89 it needs the MAF sensor regardless of the intake. Only exception would be an aftermarket computer like a Terminator X. So I would start with getting the MAF situation figured out.

 

[Aoneill5.0]

If it’s a ‘89 it needs the MAF sensor regardless of the intake. Only exception would be an aftermarket computer like a Terminator X. So I would start with getting the MAF situation figured out.

I ain’t arguing but this is a post I got earlier…

Does any of that make sense to you?

I do agree with you I’m thinking

No MAF Code tho??


Andy O'Neill sorry just saw this!

Yes with the Holley terminator x, you no longer need the maf.

The car is tuned based off of speed density/Map sensor, and the idle is aided by the typical IAC.

So no longer need the MAF sensor

 

[Noobz347]

Given the intermittent nature, two things come to mind:

The fuel pump is internally bypassing and/or cavitating. You can confirm this by getting a fuel pressure reading during the no-start condition.

That aside, I would bet a dollar that your Thin Film Ignition (TFI) module is bad. Are you still running an OEM distributor and TFI?

 

[General karthief]

Is this the same car?

https://stangnet.com/mustang-forums/threads/quick-question-89-gt.924831/

 

[rednotch]

I ain’t arguing but this is a post I got earlier…

Does any of that make sense to you?

I do agree with you I’m thinking

No MAF Code tho??


Andy O'Neill sorry just saw this!

Yes with the Holley terminator x, you no longer need the maf.

The car is tuned based off of speed density/Map sensor, and the idle is aided by the typical IAC.

So no longer need the MAF sensor

I'm lost... How are you getting codes with the car running on a Holley terminator x set up.... The eec IV shouldn't be controlling anything if someone swapped it to the holley terminator

 

[Aoneill5.0]

Given the intermittent nature, two things come to mind:

The fuel pump is internally bypassing and/or cavitating. You can confirm this by getting a fuel pressure reading during the no-start condition.

That aside, I would bet a dollar that your Thin Film Ignition (TFI) module is bad. Are you still running an OEM distributor and TFI?

 

[Aoneill5.0]

I have changed out the TFI to a new one from Napa and

I'm lost... How are you getting codes with the car running on a Holley terminator x set up.... The eec IV shouldn't be controlling anything if someone swapped it to the holley terminator

greased it well during install and the Disttributor I’d say is
Original.

 

[Aoneill5.0]

I have changed out the TFI to a new one from Napa and


greased it well during install and the Disttributor I’d say is
Original.

 

[Aoneill5.0]

I'm lost... How are you getting codes with the car running on a Holley terminator x set up.... The eec IV shouldn't be controlling anything if someone swapped it to the holley terminator

I’m not running the Holley, that was a screenshot of another guys post to me.

I’m running the Edelbrock performer intake.

 

[Mustang5L5]

I'm lost... How are you getting codes with the car running on a Holley terminator x set up.... The eec IV shouldn't be controlling anything if someone swapped it to the holley terminator

I'm with you.


How are you getting standard Ford 2-digit codes with a Holly Term X? Those codes indicate you have a standard A9x ECU in the kick panel. The Holley setup uses a completely different way of doing "codes" based on sensors going outside specified ranges. Code 98 is purely a Ford A9x code, so it makes me think you do NOT have a term x.

In that case you will need a MAF.

 

[Aoneill5.0]

Exactly

I’m not running the Holley
That was another post to me

I have a Edelbrock performer Intake

Close looking to Stock

MAF is still a question tho

I’m dealing with previous owners dreams or nightmares. Lol

 

[Noobz347]

Post images of your engine bay, harness, and EEC.

 

[Mustang5L5]

Lets back up for a second here

From JRichtker

Code 98 - basic computer internal tests not passed before it started processing the request to dump codes. Do a Key On Engine Off test before starting the engine. Wait until you see the 11 flash before pressing any buttons if you have a hand operated scanner. The computer is operating in Limp mode, so fix any codes it dumps prior to doing anything else.

98 (r): Hard fault present. The PCM is running in FMEM (Failure Effects Management Mode), so something is royally screwed up that the KOEO test should have told you about. Rerun KOEO and fix whatever you find there.

pull your ECU and take a picture of the label. Is it a mass air ECU, or did the previous owner swap in a 87-88 Speed density ECU, and then fuber up the wiring?

You really can't change the operating style of a MA A9X ECU to all the sudden run on speed density without a MAF. You can tune to change certain trims and such, but if you want to eliminate the MAF, you just swap in a factory speed density ECU (no idea why) and modify the wiring for it. So the question really is what ECU does your car actually have in the pass kick panel?

I ask this question because i've seen some really messed up stuff when it comes to wiring so it really wouldn't be the first time i've seen a 89+ mass air car rigged with a batch fire speed density ECU from a town-car, especially given that A9L's are $400+ these days but a town car ECU is $20

 

[Aoneill5.0]

Lets back up for a second here

From JRichtker







pull your ECU and take a picture of the label. Is it a mass air ECU, or did the previous owner swap in a 87-88 Speed density ECU, and then fuber up the wiring?

You really can't change the operating style of a MA A9X ECU to all the sudden run on speed density without a MAF. You can tune to change certain trims and such, but if you want to eliminate the MAF, you just swap in a factory speed density ECU (no idea why) and modify the wiring for it. So the question really is what ECU does your car actually have in the pass kick panel?

I ask this question because i've seen some really messed up stuff when it comes to wiring so it really wouldn't be the first time i've seen a 89+ mass air car rigged with a batch fire speed density ECU from a town-car, especially given that A9L's are $400+ these days but a town car ECU is $20

Ok, now we are getting somewhere, like I mentioned and I know you understand what I’m dealing with, so, I will in the next few days after this ty weather let’s up, get some pics of the ECU and go from there

I do realize that I don’t know yet how to go about this (revival) but do want a reliable product in the end.

Thanks for the input and bear with me..

On a good note for today, I dropped into the Ford Dealership, spoke with the parts guy, whom I know from another life and he took interest and offered me cost on parts needed..

SCORE.. HE will be getting a nice Christmas gift!!

 

[Aoneill5.0]

Post images of your engine bay, harness, and EEC.

Will do, shortly,

I can tell I’m entering a hot mess here but that’s the reason for the Mid Life purchase
Haha

 

[General karthief]

I have not done the idle Surge/start checklist yet as I dont think I’ll find anything obvious.

the checklist is not for finding 'obvious ' issues. At this point I would start checking to see if you have a 4 cyl swapped to V8 with gt trim and an engine that is not an HO too.
i'm hoping you just need to add back the maf and be good.

 

[Noobz347]

I can tell I’m entering a hot mess here

I was kinda getting that impression too.

 

[General karthief]

I hate people that 'think' they can slap on this or leave that off and then when it doesn't go right they sell it off for someone else to deal with.
Now that you're 'the one' we need you to verify some things so we can help you get this 'mid life mess' running right.
Verify what computer is in the car, and if the car is actually an original V8 GT car. We can go from there.

 

[Aoneill5.0]

I was kinda getting that impression too.

the checklist is not for finding 'obvious ' issues. At this point I would start checking to see if you have a 4 cyl swapped to V8 with gt trim and an engine that is not an HO too.
i'm hoping you just need to add back the maf and be good.

I hate people that 'think' they can slap on this or leave that off and then when it doesn't go right they sell it off for someone else to deal with.
Now that you're 'the one' we need you to verify some things so we can help you get this 'mid life mess' running right.
Verify what computer is in the car, and if the car is actually an original V8 GT car. We can go from there.

Ok Good plan and I appreciate you guys stickin around. more info to follow..

From the Ground up..(good Pilot book BTW)