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Joined: Oct 2003
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here's whats happen'n, when i start the car it revs up high and does'nt come down to correct idle till car gets warmed up, suspected iac, but cleaned and tested and seamed to be working fine. when starting to drive throttle starts to run away,reving high without downshifting and when it does downshift it slams into gear, got code542 and was going though troubleshooting for faulty fuel circuit, changed fuel pump and front o2 sensor, checked all electrical grounds. test circuit was fine. could this be a bad fuel pressure regulator? what are signs of a bad fpr. also car wants to overheat once in awhile, suspect bad cooling temp sensor,could this have a effect on wy the throttle all over the place.
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Joined: Sep 2003
Posts: 2,725
Hard-core CEG\'er
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Hard-core CEG\'er
Joined: Sep 2003
Posts: 2,725 |
Originally posted by linky:
here's whats happen'n, when i start the car it revs up high and does'nt come down to correct idle till car gets warmed up, suspected iac, but cleaned and tested and seamed to be working fine. when starting to drive throttle starts to run away,reving high without downshifting and when it does downshift it slams into gear, got code542 and was going though troubleshooting for faulty fuel circuit, changed fuel pump and front o2 sensor, checked all electrical grounds. test circuit was fine. could this be a bad fuel pressure regulator? what are signs of a bad fpr. also car wants to overheat once in awhile, suspect bad cooling temp sensor,could this have a effect on wy the throttle all over the place.
With the car overheating there are a few more likely things you should try first...
1. is the thermostat stuck open? That is the most likely cause for a car to overheat, people dont chnag them when they change the coolant like they should
2. You stand by the hood of the car and grab the top radiator hose, while someone else starts it, you should fell a surge of coolant, if you dont then the water pump has failed and that is cauisng overheating
3. Have you had your cooling system flushed within 24,000 miles
4. One of your hoses, or heater core, or radiator may be plugged a flush will take care of that though
If none of those fix the problem let me know
It sounds like your fuel pressure regulator like you said has gone bad, that is why is revs up high for, nothing is controlling it
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Joined: Sep 2002
Posts: 1,788
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You must identify your year, engine, and transmission. Without this information, we are unable to provide other than generic information.
First, check for vacuum leaks.
If none, replace the IAC. You've been wasting your time and money replacing the other stuff when there was no reason to do so.
Upon replacement of the IAC, disconnect the battery so that the EEC is forced to relearn idle strategy.
There is no evidnece from the sypmtoms you listed of any fault in the fuel system. The 542 is common on a manual transmission if you stall the engine.
Steve
98 Contour SE Sport 2.5 Duratec ATX The wifey's car
89 Taurus SHO - 246K miles
94 SHO ATX - 190K
1997 F-150 5.4L ATX - The Workhorse 150K.
ANY THREAD WITH "OMG" or "WTF" ETC IN THE TITLE WILL BE IGNORED!
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Joined: Oct 2003
Posts: 9
Newbie
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OP
Newbie
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car is a 1995 contour se, automatic trans., sucks to work on, no room. also is their a way to remove fpr without taken' intake manifold off? and don't say tiny hands..
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Joined: Oct 2002
Posts: 2,408
Hard-core CEG'er
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Hard-core CEG'er
Joined: Oct 2002
Posts: 2,408 |
Originally posted by linky:
here's whats happen'n, when i start the car it revs up high and does'nt come down to correct idle till car gets warmed up, suspected iac, but cleaned and tested and seamed to be working fine. when starting to drive throttle starts to run away,reving high without downshifting and when it does downshift it slams into gear, got code542 and was going though troubleshooting for faulty fuel circuit, changed fuel pump and front o2 sensor, checked all electrical grounds. test circuit was fine. could this be a bad fuel pressure regulator? what are signs of a bad fpr. also car wants to overheat once in awhile, suspect bad cooling temp sensor,could this have a effect on wy the throttle all over the place.
542 (O,M) Fuel pump open, bad ground or always on - Power / Fuel Pump Circuits
This is checked at output of fuel pump relay. Remove battery and AUX box, you will probably find lots of corrosion underneath.
FPR is checked with pressure gage while engine is running. Bad FPR or missing vacuum usually causes extreme rich condition or flooding. Should have rich codes if this is the case.
ECT can cause rich condition and lack of codes, but usually gets worse as engine warms up.
Make sure throttle plate is closing completely. TB may be dirty or cable hanging up.
Replace rubber hose between PCV valve and UIM, and check for other vacuum leaks.
This kind of problem is the IAC, throttle plate, PCV valve, or a vacuum leak combined with a rich condition.
"Those who cannot remember the past are condemned to repeat it" -George Santayana
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