Newly Purchased 1986 LX 5.0

Hardwerk · Apr 26, 2022

This thing still giving me fits. Changed the spark plugs out over the weekend. Little difference.

I put a temperature gun on the exhaust manifold from each cylinder. The passenger side cylinders (1 thru 4) was up to 100 degrees cooler than the drivers side (5 - 8). The temperatures would raise and then drop 50 degrees. Someone said it might be flooding with fuel and cooling off the cylinder. The car is running super rich. This would imply primarily on the left bank. Any thoughts?

I have a OBD1 on the way to check out codes. Just waiting for it to get here.

So, I've replaced the TPS, did a smoke test (didn't see any leaks), did an idle speed reset, checked/adjusted the timing (12 degrees), cleaned out bad fuel/put in fuel injector cleaner, replaced the injectors (mechanic did), checked the fuel pressure (~32 psi), replaced the plugs, running out of ideas...

Anybody got any suggestions?

Hardwerk · Apr 26, 2022

Still does this: https://photos.app.goo.gl/TxuiW4GC7QgFFxKU8

Cheapskate207 · Apr 26, 2022

I think at this point we’re gonna need to wait and see what the codes are.

General karthief · Apr 26, 2022

Did you reset the computer after all that?

Hardwerk · Apr 26, 2022

General karthief said:
Did you reset the computer after all that?

I'm not sure how to do that so I'm going to go with no. I started it without the IAC plugged in and let it warm-up and then plugged in the IAC and let run for 2 minutes.

General karthief · Apr 26, 2022

Disconnect the battery for about 30 minutes with the headlight switch turned on, turn the light switch off, connect the battery, drive the car around with some stop and go and some steady speed time. Then run the codes.

Hardwerk · Apr 26, 2022

Looks like 63 and 23 were the 2 codes I got for key on engine off test. 63 is TPS voltage too low. I have replaced the TPS so I'm guessing this is meaning some kind of wiring harness issue. Or, based on some research, this can happen with a key on engine off test and maybe I should check with Key On Engine On test.

Does this shed any light for anybody?

General karthief · Apr 26, 2022

Mustang TPS Adjustment - 0.999999v not necessary

EDIT: This post applies to 86-93 5.0 Mustangs. Seems to be a common myth, so lets sticky a thread explaining how the TPS works. Jrichker has provided the basic TPS guideline to follow. I'll just preference it with this. Adjusting your TPS to .99999999 volts is not necessary at all. There...

www.stangnet.com

This shows how to check tps setting.

Mustang5L5 · Apr 27, 2022

Code 23 is TPS voltage too high (over 1.25volts)

Code 63 is TPS voltage too low (under 0.5 volts)

Anything in the 0.5-1.25V range is acceptable, no need to chase 0.99 volts. I guess my first question is since you have both a high and low voltage code, did you erase the codes prior to running the test? One of those two could be old.

Sounds like you also did not perform the Key on, Engine running portion of the test. I would reset the codes, start the engine and let it run a few mins and then shut it off and do Key On, Engine OFF codes, and then the Key on Engine Running codes.

Hardwerk · Apr 27, 2022

Mustang5L5 said:
Code 23 is TPS voltage too high (over 1.25volts)

Code 63 is TPS voltage too low (under 0.5 volts)

Anything in the 0.5-1.25V range is acceptable, no need to chase 0.99 volts. I guess my first question is since you have both a high and low voltage code, did you erase the codes prior to running the test? One of those two could be old.

Sounds like you also did not perform the Key on, Engine running portion of the test. I would reset the codes, start the engine and let it run a few mins and then shut it off and do Key On, Engine OFF codes, and then the Key on Engine Running codes.

Yeah, I suspect these are codes from when I swapped out the TPS. I'll be clearing out and running again tonight.

Hardwerk · Apr 27, 2022

Cleared out the codes and received a code 63. The measured voltage on the TPS was 1.24. I turned the idle down to ~500 rpms and that dropped the TPS reading to .997. Ran the codes again and got an 11 (all clear).

Car is still running horribly and now at the lower idle even worse than before.

Mustang5L5 · Apr 27, 2022

Did you run the codes with engine running?

Hardwerk · Apr 27, 2022

Mustang5L5 said:
Did you run the codes with engine running?

No, I did not.

General karthief · Apr 27, 2022

He needs to visit the technical/how to thread in the 5.0 tech forum.
Lots of stuff in there that's useful.

manicmechanic007 · Apr 28, 2022

During the Key On Engine On tests with the Start tester you are to use
The Latch and Un latch of the toggle switch is hard to do with a test light and a wire
It is possible because they made the Asset students make one and use it in school back in that era
If you own one... Find a star tester

manicmechanic007 · Apr 28, 2022

manicmechanic007 · Apr 28, 2022

Not actually giving these away down at Ford when the NGS's came out but
They did not care if I inherited this one

manicmechanic007 · Apr 28, 2022

Thank God for ASE
It was them that pushed OBD2 so hard so it is easier for all makes and all independent shops now
Ford and BMW were the worst offenders when it came to special tools that cost a fortune
Nothing has changed
You want to get serious with new Fords as an independent
Its about 10-50k a month for the tools and a satellite link to Detroit last I heard
Thank God for OBD2
Replace the windshield in a BMW, water leaks on the headlight switch. You replace it
You need to go to them to put the miles back in the new headlight switch with their scan tool (new) VAG I believe
The mileage is stored in the headlight switch which has a expensive module attached wtf
Get ready for more of that

Hardwerk · Apr 30, 2022

What is the hose shown in the linked picture that has the silver connection on the end?

When I removed the intake I don't think it was connected to anything. Could this be the cause of running so bad?

Under Intake

General karthief · Apr 30, 2022

PCV valve, goes into the grommet in the back of the lower intake. Has a screen in the grommet that should be checked.

Newly Purchased 1986 LX 5.0

Hardwerk

Member

Hardwerk

Member

Cheapskate207

The left one hangs a little lower

General karthief

wonder how much it would cost to ship you a pair

Hardwerk

Member

General karthief

wonder how much it would cost to ship you a pair

Hardwerk

Member

General karthief

wonder how much it would cost to ship you a pair

Mustang TPS Adjustment - 0.999999v not necessary

Mustang5L5

That is…until I whipped out my Bissell

Hardwerk

Member

Hardwerk

Member

Mustang5L5

That is…until I whipped out my Bissell

Hardwerk

Member

General karthief

wonder how much it would cost to ship you a pair

manicmechanic007

manicmechanic007

manicmechanic007

manicmechanic007

Hardwerk

Member

General karthief

wonder how much it would cost to ship you a pair

Similar threads

Newly Purchased 1986 LX 5.0

Member

Member

The left one hangs a little lower

wonder how much it would cost to ship you a pair

Member

wonder how much it would cost to ship you a pair

Member

wonder how much it would cost to ship you a pair

That is…until I whipped out my Bissell

Member

Member

That is…until I whipped out my Bissell

Member

wonder how much it would cost to ship you a pair

Member

wonder how much it would cost to ship you a pair

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