Strange timing issue

[92 Bimini Blue]

I have a '92 Fox and I'm currently dealing with a strange timing issue. I recently purchased a heads/cam/intake motor for my car and got it installed. For some reason, with the SPOUT connector out, the timing is advancing itself physically once the engine idles for about 15 to 20 minutes and is fully warmed up.
I have tried swapping out the TFI module, but that did not fix the problem. I reused my original Motorcraft distributor, which did not seem to have any issues on my stock motor. Could the PIP sensor be causing this strange issue? I don't want to just throw random parts at this thing in hopes of fixing it.

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[AeroCoupe]

Have you checked for codes? Even if the CEL light is off there can be codes as the ECU only illuminates the CEL for emissions related codes.

 

[General karthief]

Got any vacuum readings?
Does the RPMs hunt around a little after warmup?

 

[92 Bimini Blue]

I checked the codes and got 23 and 38 one for the TPS and one for the IAC. Neither of these should affect the timing.

 

[92 Bimini Blue]

Got any vacuum readings?
Does the RPMs hunt around a little after warmup?

no vacuum readings it does hunt on cold start but not warm

 

[92 Bimini Blue]

I will say that the timing seems to start advancing right around the time the engine hits operating temperature. On a timing light, it shows a smooth advance that doesn't stop until I intervene.

 

[JD1964]

Considering the TSP plays a direct role in controlling the ignition timing advance, I would sort that and the IAC out before any continued tail chasing on the timing anomaly.

In order for a properly set base idle, you need a functional IAC. For proper timing control the base idle should be set and the associated TPS voltage needs to be within the correct range.

I know you’re thinking that because the condition happens when the spout is pulled, that means the throttle body issues are irrelevant. But do we “know” that? Perhaps the EEC is entering a base setting mode because it’s not getting the correct signals from the TPS, IAC etc….

Sort out and correct the TB and any other known issues before chasing the unknown cause of the timing advance.

 

[JD1964]

Other than that, it’s possible the EEC thinks the spout is still installed due to a short in the spout circuit . When you pull the spout with the engine running, does the engine idle charge or do you notice a stumble? Normally you can see / hear a change when it’s removed. If you don’t, maybe there’s a wiring problem.

 

[92 Bimini Blue]

Considering the TSP plays a direct role in controlling the ignition timing advance, I would sort that and the IAC out before any continued tail chasing on the timing anomaly.

In order for a properly set base idle, you need a functional IAC. For proper timing control the base idle should be set and the associated TPS voltage needs to be within the correct range.

I know you’re thinking that because the condition happens when the spout is pulled, that means the throttle body issues are irrelevant. But do we “know” that? Perhaps the EEC is entering a base setting mode because it’s not getting the correct signals from the TPS, IAC etc….

Sort out and correct the TB and any other known issues before chasing the unknown cause of the timing advance.

That definitely makes sense. I have been trying to set the IAC and the TPS in the correct range, but I do not get a lot of time before the timing starts extremely advancing itself to the point where I have to shut it down and let it cool off. Last night, while I was setting the idle after replacing the TFI in hopes it would fix the issue, the RPMs shot up and the car started to run badly. When I checked the timing mark, which was originally set at 12 degrees, the mark was pegged past 40, so I quickly shut it down. This is the first Fox I have ever owned, and also the first time swapping an engine. I apologize for my lack of knowledge; I kind of dove head first into this project. Also to add when removing or reconnecting the spout I do see and hear a change.

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[AeroCoupe]

You can set the TPS with the key in the run position and the engine not running. Idle position is idle position regardless if the engine is running or not.

 

[General karthief]

Talk a deep breath, exhale, clear your mind..
Disconnect the battery, set the idle screw so it just touches the arm for the throttle blades, check vac lines, kill 10-20 minutes reconnect the battery, set the TPS, turn key on, wait the two-three seconds fuel pump prime, start the car, get it warmed up, if you can drive it around block ok if not, feather the gas a little get it warm, do the base idle reset, don't worry about the timing, how does it run?
Check codes.