Rough idle 3 min after start-up.
Registered User
Joined: Apr 2008
Posts: 28
Likes: 1
From: Royston,Georgia
My 3500 v10 did the same backfire/no power then it would clear up and it turned out to be the fuel pump, it will get worse and then it just wont start one day. my truck done the backfire for over a year then it just died.
Registered User
Joined: Apr 2009
Posts: 27
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From: Houston, TX
cmckenna WHAT THE F$#@ do you know about fuel pressure!
You told me your vehicle would start and run with 0 PSI.
The normal mode of operation is to bleed off pressure back into the tank after a period of time. I have a fuel pressure gage and, even when at 0 psi, it starts right up without having to prime / pressurize the system.
The normal mode of operation is to bleed off pressure back into the tank after a period of time. I have a fuel pressure gage and, even when at 0 psi, it starts right up without having to prime / pressurize the system.
You told me your vehicle would start and run with 0 PSI.
I have a fuel pressure gage and, even when at 0 psi, it starts right up without having to prime / pressurize the system.
Where did I say that it RAN with zero psi? Show me where I wrote that.
Are you back to "needling" again or, was that a legitimate question?
Last edited by cmckenna; Oct 14, 2009 at 08:19 PM. Reason: Clarification
Thread Starter
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Amateur
Joined: Apr 2009
Posts: 26
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From: Minnesota
Welcome to the forum. You've come to the right place!
Sounds like the IAC valve isn't working like it should. The fact that it is OK until the engine warms up could also indicate something possibly wrong with the pre-cat O2 sensor. I'm no mechanic, but this is what first comes to mind. Maybe somebody will chime in who actually knows about these things.
Sounds like the IAC valve isn't working like it should. The fact that it is OK until the engine warms up could also indicate something possibly wrong with the pre-cat O2 sensor. I'm no mechanic, but this is what first comes to mind. Maybe somebody will chime in who actually knows about these things.
It turns out that it was the pre-cat O2 sensor. I let this problem go for along time and now I believe tha Cat is some what plugged. Thia may prove to be a costly mistake on my part. This O2 sensor I believe also affected the shifting of the transmission. The tranny would sometimes not shift into overdrive, but after replacing tha sensor I've not had any problems with that issue. Thanks to all for your help even if this thread did get alittle out of hand. (Good entertainment)
Later
Dan
Veteran
Joined: Jun 2009
Posts: 320
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From: up north
BINGO , post 2,5 and 16 nailed it and you just did the test , unplug the sensor . The PCM will run off preset settings and but generate a CEL . If the problem goes away , replace the sensor . It's not something to leave for an extened period , but a few days is harmless , make sure the harness is wired away from the exhaust manifold .
Glad your all fixed up OP . It only takes one bad sensor to eff things up .
I don't frequent this forum anymore because I sold the beast , but was subscribed to this one . I still push Mopars , both jeeps have V8's , one 5.2 , one , 5.9
Don't stress about the cat , if it doesn't rattle , it's 9.5/10 times still good . If someone could show me a clogged cat , do so , I've never seen one . Pics or nothing !
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Joined: Jul 2016
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You had mentioned you replaced the upstream O2 sensor. Would you mind telling me was it the left or the right? Also, did the problem stay away and not come back after an extended period of time?
Thanks a lot!
Nick
Administrator
Joined: Apr 2010
Posts: 87,461
Likes: 4,218
From: Clayton MI
Hello Detour, I know I am about 10 years behind, but hoping you are still active on this forum site. I have the EXACT same problem with my '99 Ram 1500. I replaced the IAC sensor a few months ago and it seemed to go away for about 2 weeks, then it was back.
You had mentioned you replaced the upstream O2 sensor. Would you mind telling me was it the left or the right? Also, did the problem stay away and not come back after an extended period of time?
Thanks a lot!
Nick
You had mentioned you replaced the upstream O2 sensor. Would you mind telling me was it the left or the right? Also, did the problem stay away and not come back after an extended period of time?
Thanks a lot!
Nick
