Monte Carlo Repair Help Have a Monte problem and need help? Good at troubleshooting? Discuss it here!

fuel pressure drop off??

  #1  
Old 03-27-2012, 06:38 PM
mwjames's Avatar
Thread Starter
Join Date: Sep 2011
Location: Minnesota
Posts: 370
Default fuel pressure drop off??

So i went out and bought a fuel pressure test kit. key on engine off it started at about 50psi then dropped down to 40psi slowly, running it held steady at 42psi. Turned off it dropped to 36psi instantly not that it should matter.

Everyonce in a awhile my car will die out of no where and this is my suspect.

I'm going to be getting a new fuel filter soon, could it maybe be a gas cap to?

inspect the fuel lines? fuel regulator replacement?

Any help or previous experiences with this type of problem by anyone else is appreciated
 
  #2  
Old 03-27-2012, 07:26 PM
mwjames's Avatar
Thread Starter
Join Date: Sep 2011
Location: Minnesota
Posts: 370
Default

also i do not have all the hoses hooked up and running to the canister in the back, it's a 5th gen 3800
 
  #3  
Old 03-28-2012, 05:50 AM
Join Date: May 2008
Posts: 678
Default

I doubt that this is your issue with it running. Gas cap has nothing what so ever to do with fuel pressure. How fast does it drop from 50 to 40? If I holds 42 running and fires up every time, I would look somewhere else. Usually a sudden stall is ignition related. It could be an ignition module, cam, crank sensor, etc.
 
  #4  
Old 03-28-2012, 08:10 AM
ChibiBlackSheep's Avatar

Monte Of The Month -- August 2014
15 Year Member
10 Year Member5 Year Member3 Year Member1 Year Member
Join Date: Sep 2008
Location: Southeast PA
Posts: 25,136
Default

Pull the vacuum hose off the FPR, if it smells like gas / has gas in it, the FPR could be going bad.
 
  #5  
Old 03-28-2012, 11:32 AM
The_Maniac's Avatar

Monte Of The Month -- December 2011
Monte Of The Month -- September 2014
10 Year Member
5 Year Member3 Year Member1 Year Member
iTrader: (2)
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,153
Default

Typically a fuel pump will not "intermittently" stall. It will either stumble or full failure. Your PSI results sound reasonable that things are good. Changing the fuel filter is not a bad idea (even if it's not the cause, as it's probably factory original).

Follow Chibi's check for the FPR. But I would ALSO do a check if you have vacuum line problems (easy check is take a can of starting fluid and mist it around all vac lines and connections, listen for when the idle changes, this will let you know your problem area).
 
  #6  
Old 03-28-2012, 06:19 PM
mwjames's Avatar
Thread Starter
Join Date: Sep 2011
Location: Minnesota
Posts: 370
Default

It took approximately 2 minutes to drop from 50-40. I willcheck out the fpr and vacuum leaks tomorrow hopefully. Isn't the fuel pressure suppose to hold steady with engine off to? And like I said the sensor that runs the vacuum line to the evap canister is not hooked up all around because idk were its all suposeto go, can that effect anything?
 
  #7  
Old 03-29-2012, 08:13 AM
ChibiBlackSheep's Avatar

Monte Of The Month -- August 2014
15 Year Member
10 Year Member5 Year Member3 Year Member1 Year Member
Join Date: Sep 2008
Location: Southeast PA
Posts: 25,136
Default

Anything not hooked up, could be a vacuum leak and affect performance.
 
  #8  
Old 03-30-2012, 10:53 PM
mwjames's Avatar
Thread Starter
Join Date: Sep 2011
Location: Minnesota
Posts: 370
Default

replaced the fuel filter today pressures still the same as before, couldn't really tell if the gas smell was coming from the fpr or from when i did the pressure test. I haven't had a chance to pick up the starting fluid to check for the vacuum leak yet.

Also my check engine light kicked on throwing code p0141 i'm assuming that's pretty much telling me my cats clogging and holding to much heat, since I might be moving to the metro area soon i might actually go get a magnaflow high flow cat to replace it. I would possibly go for the downpipe with cat but previous owner put a glass pack were the flange was behind the cat so this is what i'm looking at http://magnaflow.com/02catalytic_con...versal=99306HM napa's online site says there universal cat for my car is 2in inlet and outlet the magnaflow is 2.5in inlet outlet. the highflow should work right?
 

Last edited by mwjames; 03-30-2012 at 11:11 PM.
  #9  
Old 03-30-2012, 11:17 PM
The_Maniac's Avatar

Monte Of The Month -- December 2011
Monte Of The Month -- September 2014
10 Year Member
5 Year Member3 Year Member1 Year Member
iTrader: (2)
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,153
Default

Code P0141 is listed as O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2). Sounds like you just need to change the rear/downstream O2 sensor.

As for the fuel pressure dropping, I believe this is normal when the car is off (there is nothing forcing the fuel pressure to remain high). Plus, dropping a little prevents stress on some of the lines and parts.

So, what is the issue with the sensor? Is it that you don't know where the wiring harness is for it? Or how it's supposed to mount? Got a pic you can send?

That sensor that you mentioned is not hooked up is probably the cause of the issue. I believe that is the "purge solenoid". A friend of mine had a vac leak (not sure if it was going in or coming out) and caused weird stumbling from time to time and the occasional stall. We fixed the vac leak, no more issues.
 
  #10  
Old 03-31-2012, 01:10 PM
mwjames's Avatar
Thread Starter
Join Date: Sep 2011
Location: Minnesota
Posts: 370
Default

I uploaded a pic of the sensor into my profile, every once in awhile it throws a code for it. I didn't write it down just cleared it everytime.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
joe111599
Engine/Transmission/Performance Adders
9
06-10-2016 07:01 PM
Randy Biron
Engine/Transmission/Performance Adders
3
07-14-2012 08:07 PM
0MC4
Monte Carlo Repair Help
1
09-15-2009 10:26 PM
kruqnut
Monte Carlo Repair Help
0
09-13-2009 10:41 AM
jts01ss
Monte Carlo Repair Help
0
10-20-2008 09:01 PM


Thread Tools
Search this Thread
Quick Reply: fuel pressure drop off??



All times are GMT -5. The time now is 02:26 AM.