My car (5.0L) has developed irratic throttle response at only about 1/4 throttle. I'm fairly certain this is the work of a bad TPS however the fricken thing tests out perfectly in both voltage and resistance tests. The problem only occurs speratically. Has anyone else experianced a simialr phenomenon when a TPS only acted up when it wanted too?
I cannot pull codes from this EEC or else I would have tried that. (Canadian models did not have diagnostic connectors in 86)
Everything remotly possible of causing this problem has been checked out. The car is still perfectly drivable, this is just driving me crazy. If it gets worse I'm just gonne buy a new TPS and cross my fingers.
O2, ACT, MAP, MAFF, CTS, TAB, TAD, fuel pressure, vacuum, egr, IAC all are functioning properly.
Mine ('88 5.0) did that at about 170,000 miles. When I turned it off, it was running fine. Next time I started it (30min. later), it ran like . Had to hold down the gas to keep it from dying, & hold down the brake to regulate speed. Next day it ran fine, next day , alternating this way for several days. Computer said TPS, EGR not seated, & thermactor (melted plastic valve had been replaced with an iron pipe tee:D). I tested the TPS with a digital voltmeter & it seemed OK, but it still ran like part-time . I finally borrowed a TPS from an old Lincoln & that fixed it for a week, so I bought a new Autolite TPS, figuring if one lasted 170K, another one might also.
Mine doesn't really run that bad, just hesitates and surges a bit. I'm gonna replace the TPS tomorow on the basis, their is nothing else that could cause this at only one throttle position.
I just unpluged mine, started idileing alot better
:dunno:
hhhuuu?
the trick to the tps is you have to use an buttstuffog meter, not the digital. also you need to move very very slowly with the throttle linkage.
jcassity got it: I tryed it with an buttstuffogue today and it has a bad spot. Origionally I had tested it with my snap-on diagnostic tool. Funny a $10 voltmeter cought a problem a $2000 tester could not.