Mustang running/idle problem

**Jared** · 03-13-2009, 01:06 AM

My friend bought the 87 lx that was on here last friday. He picked up a set of headers, a edelbrock performer intake and a 70mm bbk throttle body for it. We put it all on today and the car seems to be running really rich and idles like crap. Wondering if anyone has any ideas of what to check we screwed around with it all night and cant figure it out. It will run ok and go like hell with a big cloud of black smoke behind it then a minute later it wont go above 3000 rpm. Any ideas would be greatly appreciated.

**70 cutlass 442** · 03-13-2009, 01:45 AM

check engine light on?

**Reverend Cooper** · 03-13-2009, 06:03 AM

did you check the tps adjustments,and im assuming this happened after your install of parts,and it wasnt that way previous if i understand correct. unplug the fuel pressure regulator from the vacuum side,see if any fuel is in the line,also did you remove the plugs and wires on install of the headers,wires on correct cylinders or damaged upon removal.if you replaced the intake did you get all the air burped from the coolant system a temps sensor with a air picje by it will make the car do very odd things.

**-stew-** · 03-13-2009, 10:52 AM

Originally Posted by Jimmy MF'ng Johnson!

did you check the tps adjustments,and im assuming this happened after your install of parts,and it wasnt that way previous if i understand correct. unplug the fuel pressure regulator from the vacuum side,see if any fuel is in the line,also did you remove the plugs and wires on install of the headers,wires on correct cylinders or damaged upon removal.if you replaced the intake did you get all the air burped from the coolant system a temps sensor with a air picje by it will make the car do very odd things.

**-stew-** · 03-13-2009, 10:55 AM

Also: speed density ftl.

**Jared** · 03-13-2009, 11:12 AM

How do I check the tps adjustment? The plugs and wires are new and put on after everything else we checked those first there on right. We burped it for about 2 hours last night. Im gonna check the fuel pressure regulator today and see if theres fuel in the line whats it mean if there is? The check engine light is off. Thanks for the ideas.

**MurphysLaw88GT** · 03-14-2009, 08:24 AM

Originally Posted by -stew-

Also: speed density ftl.

yep

**DirtyMax** · 03-14-2009, 08:30 AM

As elementary as it sounds, did you gap the plugs? I made the mistake of just tossing a set in once and the car would not run for poo. Check that the firing order is correct and the distributor isn't flipped, timing, etc. Good luck.. hopefully it's something simple.

**xxtremeteam** · 03-14-2009, 08:34 AM

If this car was the black one for sale here the old owner made a post about similar issues
last year
http://brewcitymuscle.com/forum/showthread.php?t=32948

**SMOKDU** · 03-14-2009, 09:42 AM

sounds like spark arcing off the headers . tps or mass air meter would not rev limit. do you have a air leak after the mass air meter(between the mass air meter and the throttle body ? sounds like a bad plug (cracked) or bad or melted wire hitting header. id also check cap and rotor sounds like a spark issue to me

**MurphysLaw88GT** · 03-14-2009, 04:36 PM

Originally Posted by Jared

My friend bought the 87 lx that was on here last friday. He picked up a set of headers, a edelbrock performer intake and a 70mm bbk throttle body for it. We put it all on today and the car seems to be running really rich and idles like crap. Wondering if anyone has any ideas of what to check we screwed around with it all night and cant figure it out. It will run ok and go like hell with a big cloud of black smoke behind it then a minute later it wont go above 3000 rpm. Any ideas would be greatly appreciated.

I assume it is a speed-density? or has this been converted to a mass-air?

**method man 001 87 lx** · 03-14-2009, 06:38 PM

no the car has no mass sensor. just a short ram janky ass intake on it.

**method man 001 87 lx** · 03-14-2009, 06:45 PM

Originally Posted by xxtremeteam

If this car was the black one for sale here the old owner made a post about similar issues
last year
http://brewcitymuscle.com/forum/showthread.php?t=32948

thats funny i think it is the same car. its listed in there that it had an intake and h-pipe. and he had bosch plugs in it. And when i picked the car up those were the only mods and it did have almost like new bosch plugs in it. and the wires do look kinda shitty. thanks everyone for all the help. if you can think of anything else please let me or jared know thank you.

**Reverend Cooper** · 03-14-2009, 06:59 PM

it there is fuel in the vacuum line the fuel pressure regulator is leaking internally repl. i think you proll do have a spark issue or plug issue.

**Jared** · 03-16-2009, 01:52 AM

Figured out the problem tonight. The vacuum line to the map sensor wasn't hooked up we rushed getting it together and I missed it. It runs awesome now thanks for all the advice I really appreciate it.

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