QuestionSo are you trying to tell me that your Crystal Ball is in the Shop for repair too, Mr. Wizard?
I'm hip to the fact that the TPS in not temp sensitive. My only thought on that was maybe it would run ok until it went into closed loop. Anyway, this is getting beyond weird. I've been driving it for 2 days now with the TPS disconnected and still no "check engine" light. The CO is .03% and HC is about 14 PPM at idle. Cleans up at 2500rpm (or when the Cat. lites off I suspect).
One other thing I might mention is that with the TPS disconnected the ignition timing goes to full advance, or there about, (and I would think that would be normal) so I did back off on the timing a bit in hopes to keep the NOX down. Other than that it runs great and doesn't ping.
Oh and the EGR temp sensor connector has the blanketing plug on it. Not that that has anything to do with anything at this point.
THX,GARY
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The text above is a follow-up to ...
-----Question-----
I have a 91 4Runner with a 3VZ that starts and runs fine cold but has it warms up it loses power and will finally almost stall no matter what the throttle position is. Fuel pressure hangs around 38 to 42 at all times. Now heres the trip: When I disconnect the TPS it runs fine and doesnt set any codes. (being a federal spec. I dont think an open or shorted TPS circuit will set a code). Oh yes , its a 5-speed with 156000mi. fresh heads, fresh fuel, ig and cam timing right on, new EFI temp sensor and knock sensor with pig tail harness, the Air Flow meter pins out ok along with the TPS (when its connected). I cant find any bad cold crimp slices in the harness. All vacuum is routed correct and the EGR is not sticking. Keep in mind the turd runs 99% fine with the TPS disconnected. I have not checked O2 voltage feed back (I got lazy). It relly feels like its losing fuel pressure, but why only with TPS connected and I dont think my fuel pressure gauge is lieing. I know its not. Could it have good pressure and low volumn. I dont think so. GARY
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you should get a code 41 for an open or short in the TPS.
EGR gas temp code 71 is the only one that is CAL spec specific.
So it should light the check engine light if disconnected.
I would start looking there first.Maybe a pinched wire?
TPS is not temp sensitive, so Im puzzled why it would be connected to a "runs well cold but not hot" scenario.
TPS does correct fuel trim as an input to the ecu, so when disconnected , the default data in the ecu is what its using to set your fuel injection duration.
I suspect if you had a fuel pressure issue it would run like crap all the time.
Mike
AnswerI keep the crystal ball in the safe.
I usually use smoke and mirrors.
The egr temp is plugged on non Cal emmisions vehicles.
Ive seen that plug magically disappear and a tech be puzzled with an egr temp sensor code on a vehicle with no sensor.
Anyways...
I pulled the TP off my associates truck at work, same year as yours and BAMM, check engine light and code for open circuit in TPS.
I would suspect the problem lies there somewhere.
I cant duplicate your symptom with a like vehicle, and cant say Ive seen it before.
By the terminology you use and your descrition, you sound like you know what your doing. Keep at it. Sounds like your on te right track.
Ill ask around.
Id love to actually get my hands on it.
Over the internet my psychic abilities are limited.
Mike
