5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
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well my girl is gettin sick whenever i start her up she starts fine. then then rpms come down after the initial rev and flucuate from 600 rpm to about 900 rpm. when this is happening the oil pressure gauge jumps around randomly, but never goes below the red line at the bottom... now if i put my foot on the gas bringing the rpms up to about 1200 it will stay steady. if i dont warm it all the way up to normal running temp before i start driving it will backfire badly in second gear when im accelerating. it even backfired in 4th gear yesterday and even after it warmed up it backfired. im not sure whats going on, was wondering if anyone else has had this problem before. i put new plugs, wires, and distributor cap in it about a year ago. im guessing its not that. its frpp 9mm wires, oem plugs and msd cap. also im not sure if this is related but the other day i stoped suddenly and my car stalled, when it did the amp light and the check engine light came on. i restarted it and they both went off... anyways if anyone has any ideas what it could be im all ears... btw its an 88 gt with stock engine, either 330k miles or 230k, but the previous owner said it was rebuilt.... i dunno any help would be greatly appriciated... thank you
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I would clean the IAC first and check your TPS voltage
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89 2.3 Turbo, 82 T-Top Notch 5.0 and 86 GT Black in and out with 306 AFR 165's and comp XE 276, T-5Z, Smoothed Engine Bay, Battery in Trunk, SLP's, Bolt-on's
the check engine light isnt on, so i dont know if any codes will pop up....
The only way to find out is by running a DIY KOEO/KOER/Cylinder Balance Self-Test .... there are failure codes that will not cause the CEL to turn on, you should also verify the basic items...... fuel pressure, initial timing. Regarding the TPS..... if you don't have a TPS related failure, it's OK.... no need to adjust a non-adjustable sensor if the EEC sees it doesn't have a problem. LUK
__________________ ACRONYMS:
LUK=Let Us Know, GL=Good Luck, LMK=Let Me Know, JIC=Just In Case, BTSTDTRT=Been There Seen That Done That Repaired That, YCYDYP=Your Car Your Dough Your Prerogative and the classic... DILLIGAS=Do I Look Like I Give A S***
1986 GT-X303-289 heads-1.72 rockers-RG 4+1 Trans.
Quote:
Originally Posted by Joel5.0
Great thoughts will overwhelm a feeble mind.
There is never money to do it right, but there's always money to do it over.
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88, speed density or converted to MAF? Mine was doing similar things and eventually found it to be vacuum related to the hose to the MAP being old and rotted. Mine was a pin hole leak and it made the car run like crap and misfire here and there and buck around. Replaced the hose and presto runs like a champ... well a ugly partially paint stripped, old rotted tires, ripped top champ anyway
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Brent
1983 F150 351W (beater)
1988 Mustang EFI 302 ( SOLD :{ )
1994 Suz GSXR 750W (Too Cold)
2000 Pont Grand Am (POS) catch on fire already
2000 Mits Eclipse GT (upcoming rebuild)
2007 Kaw Ninja 250 (GF's)
its converted to maf, how would i check for the vaccum leak? it only does it when i first start up, and it doesnt do it everytime. sometimes when i start it up, it runs fine... and sometimes its worse than other times...
If its been converted clean IAC and MAF first, verify the spliced in pigtail wiring has not come loose. There are many ways to check a vac leak, everyone like something different. Professionals use smoke, some spray a shot of carb cleaner around suspected areas, I personally use a plumbers torch witha rubber hose.Iturn on the valve and move the end of the hose around the vacuum hoses and ports and listen for a change in the idle...
__________________
Brent
1983 F150 351W (beater)
1988 Mustang EFI 302 ( SOLD :{ )
1994 Suz GSXR 750W (Too Cold)
2000 Pont Grand Am (POS) catch on fire already
2000 Mits Eclipse GT (upcoming rebuild)
2007 Kaw Ninja 250 (GF's)
ug, im not very good at doing this kind of troubleshooting think it would be a good idea to take it to my mechanic? just dont want him to give me alaundry list of stuff i dont really need to fix....
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bad sputtering and backfiring problems....
whenever i start her up she starts fine. then then rpms come down after the initial rev and flucuate from 600 rpm to about 900 rpm. when this is happening the oil pressure gauge jumps around randomly, but never goes below the red line at the bottom... now if i put my foot on the gas bringing the rpms up to about 1200 it will stay steady. if i dont warm it all the way up to normal running temp before i start driving it will backfire badly in second gear when im accelerating. it even backfired in 4th gear yesterday and even after it warmed up it backfired. im not sure whats going on, was wondering if anyone else has had this problem before. i put new plugs, wires, and distributor cap in it about a year ago. im guessing its not that. its frpp 9mm wires, oem plugs and msd cap. also im not sure if this is related but the other day i stoped suddenly and my car stalled, when it did the amp light and the check engine light came on. i restarted it and they both went off... anyways if anyone has any ideas what it could be im all ears... btw its an 88 gt with stock engine, either 330k miles or 230k, but the previous owner said it was rebuilt.... i dunno any help would be greatly appriciated... thank you 
