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Code 42, and IAC valve... ideas? by AL87
Started on: 11-07-2013 07:26 PM
Replies: 3 (137 views)
Last post by: 84fiero123 on 11-08-2013 07:36 AM
AL87
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Report this Post11-07-2013 07:26 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
I have a code 42, and for all intensive purposes my 2.8 has an adjustable fuel pressure regulator, the engine is modified.
ideas?
leaking injector?
mis-adjusted fuel pressure regulator?
bad throttle position sensor?

the engine stumbles with the slightest throttle input anywhere under 2k, any rpm higher than that and the throttle response is fine.
I think the tps is sending the incorrect throttle input and is telling the ecm that the throttle input is greater than what it actually is.

engine does not fire right off, like it should, during a cold start. maybe my timing is off? (last time I set it, all cylinders were even at 11*btdc)

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Rick 88
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Report this Post11-07-2013 08:45 PM Click Here to See the Profile for Rick 88Send a Private Message to Rick 88Edit/Delete MessageReply w/QuoteDirect Link to This Post
I have a 3.4 exhibiting the same low rpm problem. However, mine starts on the first crank. I have replaced the TPS with no change. My regulator is stock. I need to check it. Apparently they can leak and cause drivability issues.

[This message has been edited by Rick 88 (edited 11-07-2013).]

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AL87
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Report this Post11-08-2013 03:04 AM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
I just replaced the TPS and IAC valve,
I checked and reset the timing (was 12* btdc and I set it back to 10)
I'm resetting the idle now and will drive it later and pay attention for any noticable improvements.

I disconnected the battery, so everything will be reset. wish me luck! XD

[This message has been edited by AL87 (edited 11-08-2013).]

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84fiero123
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Report this Post11-08-2013 07:36 AM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
I believe I had a code 42 a while ago and did some tests of a few things and found after pulling the distributer cap that the pickup coils protective coating had started to disappear. I pulled the distributer and changed it and that was the end of that.

now I say always test never just replace parts at random because it can get very costly. but if you see the coating starting to disappear around the pickup coil and an intermittent check engine light when the engine starts to run like crap chances are that could be your problem.

Edit to add, it could have been code 43, my memory is shot and it was last year or the year before.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

[This message has been edited by 84fiero123 (edited 11-08-2013).]

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