I have a 3.8L in a 96 that was running great until one day it just had no power 5 minutes after startup. No error codes, has good power when cold but hot in gear can't move stays at 500 rpm with full throttle. Checks fuel pressure all sensors, pulled off exhaust, replace cam and crank position sensors and checks spark. Timing is a little advanced and looks good but as soon as engines gets warm the timing starts to slow down and eventually goes to 10 AFTER TDC. When cold it is 30 BEFORE TDC. Have seen several threads with this symptom but no one with answers. Very confusing why timing backs off so much - this seems like the cause of the problem. Very repeatabe - does it every time. Cool down runs good, heat up and slowly deteriorates until there is nothing there even with fuel pressure on rail at 40 psi+. Anybody ever had this or know if a fix ?

 

I probably shouldn't be the first one to take a stab at this.
Did you check or replace the ECT (engine coolant temperature) sensor? Did you check the PCM? I would guess that the ECT sensor actually works because it is through the ECT sensor that the PCM knows the engine is warm. So if the ECT sensor checks out o.k then the PCM is confused. Any way that's my guess, and not more than that.
I would disconnect and reconnect it, maybe take it out and clean everything including ground connection. In general it is advisable to check all ground connections and grounding straps. If it does not help i would replace it with a known good one.

 

I would suspect the engine knock sensor may be playing tricks with the engine timing.
I believe it is located just above the flywheel area at the end of the engine block. Check the connections first , if no change consider replacing it.
Where was the cam sensor that you replaced ?

 

Thanks for the comments and help. I did check the ECT and measures in range but did not replace. I did not check the PCM but don't know how without swapping it out and don't have a spare. I was thinking knock sensor myself but can't find one on the engine and the ALLDATA and Ford engine control docs say that it does not use a knock sensor and no one sells it for a 96 so I figure that kind of eliminates that one on this car.

Has there even been a case that the torque converter locks up when hot. I am not sure if I am seeing an engine problem or just load that the engine can't overcome?

Thanks for the ideas - look forward to any one else that has heard or seen this kind of issue. Has anyone ever heard of this problem before ? I have read similar posts on different sites but no one indicated the problem had ever been answered in the posts I read.

 

I was reading through your posts again. Still I would go for a replacement PCM. I cannot see how a transmission issue would influence ignition timing.

Maybe you can negotiate a deal with a junk yard giving you a reduced restocking fee if the replacement PCM does not help the situation.

Good luck.

 

The T-bird is fixed. Problem was harmonic balancer was broken on the hub about 1/8" outside of the seal. So seal was not leaking but the 35 tooth wheel was not aligned with the keyway anymore and the timing showing on the balancer was not the same as the crankshaft. Not exactly sure why the computer was trying to retard timing so much but the root problem was the "tone" wheel was not aligned to the crankshaft and finally got so bad it was moving. Replaced the balancer and the engine runs like a top. Had to pull the front cover to remove the inch of hub behind the seal so replaced timing set, seal, and ready to go another 100 K+.

After talking to some other Ford Mechanics they say that this aluminum damper hub has been a problem so I will keep my eyes out for this and wanted to make sure other where aware of this issue. I had validated the wheel was attached to the balancer but never checked that the hub was really aligned at TDC for #1 - I came from the days when these things were cast steel and only worried about the rubber deteriorating.

Thanks to all that tried to help.