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  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

Car Running Like Crap

  • Thread starter Thread starter bdemutis
  • Start date Start date Oct 26, 2017
B

bdemutis

Member
Oct 8, 2017
18
3
13
Oct 26, 2017
#1
  • Oct 26, 2017
  • #1
For being a diesel mechanic I’m making myself feel pretty dumb but yet again we don’t have all these vacuum lines and other stuff.

Car sat for two years or so got it running after putting the new intake manifold on.
First had a number 8 misfire just replaced injectors because they were all rusty and crappy from sitting out of car.

Car runs now but idle keeps surging up and down checked all vacuum lines found the canister purge valve line was all rotted. Car smells like it’s running really rich and exhaust burns your eyes. No more misfire code but still running rough and hesitant throttle. Need some suggestions on what to check.
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Oct 26, 2017
#2
  • Oct 26, 2017
  • #2
First thing. Make sure the charging system is in tip top shape. A bad alternator diode can cause surging.

Howto perform charging system voltage drop test
https://www.stangnet.com/mustang-fo...perform-charging-system-voltage-drop-test.56/

Do you have an ODB2 scanner? It may make short work of this problem.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

Is the fuel regulator intake vacuum reference line connected and leak free? What is the fuel pressure with the reference line connected and dis-connected?

Pinch off or disconnect and plug the EVAP purge line at the throttle body. Does this improve idle?

With an ODB2 scanner we can find out things like:
  • MAF flow
  • Long term fuel trim (LTFT) values
  • O2 sensors
  • ODB2 mode 6 misfire data.
 
Last edited: Oct 26, 2017
Reactions: imp
B

bdemutis

Member
Oct 8, 2017
18
3
13
Oct 26, 2017
#3
  • Oct 26, 2017
  • #3
wmburns said:
First thing. Make sure the charging system is in tip top shape. A bad alternator diode can cause surging.

Howto perform charging system voltage drop test
https://www.stangnet.com/mustang-fo...perform-charging-system-voltage-drop-test.56/

Do you have an ODB2 scanner? It may make short work of this problem.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

Is the fuel regulator intake vacuum reference line connected and leak free? What is the fuel pressure with the reference line connected and dis-connected?

Pinch off or disconnect and plug the EVAP purge line at the throttle body. Does this improve idle?

With an ODB2 scanner we can find out things like:
  • MAF flow
  • Long term fuel trim (LTFT) values
  • O2 sensors
  • ODB2 mode 6 misfire data.
Click to expand...
I have a blue tooth scanner just need to download a app I sold my snap on scanner to the tool guy a few months ago lol. Vacuum lines are all connected I don’t hear any vacuum leaks the evap is disconnected already because the line after the valve that goes in the wheel well rotted off and I didn’t have time to remove the tire and fender well yet. But I’ll plug it at the throttle body and see if it helps.
 
B

bdemutis

Member
Oct 8, 2017
18
3
13
Oct 28, 2017
#4
  • Oct 28, 2017
  • #4
I plugged the vacuum line in the back of the throttle body car ran great so I pulled the fender down replaced the rotted line and hooked it up throttle has alitle hesitation when stepping on it hard it hiccups.
 
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