Mustang Evolution Forum banner
Status
Not open for further replies.

idle probs / throttle lag

2K views 9 replies 8 participants last post by  Zinda 
#1 ·
Hola!

I'll get right to the chase:

125k, all stock other than CAI, shorty headers

1.) I start the car after it's been sitting for long enough to get cold ( hours / days ), and it'll go up to about 100o rpms and immediately die. It'll do this repeatedly if I don't give it gas ( sometimes it'll still die with the extra gas), holding it at about 1500-2000rpm. Then once i let off the throttle, it'll start to "search" for idle, 1200 to ~500 then to (higher) 1300 to 400, high, low, high low, then dies.
Even after driving around for about 5 minutes, if I put the clutch in, and leave in neutral it'll rev down and die.

2.) I'll shift into 2nd from 1st while accelerating (it also does this if I slow down in 2nd, and get back on the throttle EX: turning a corner, and then speeding up), give it moderate to heavy throttle, and it'll sort of bog down / lag several times, each time getting shorter in duration until it starts speeding up.


Any ideas??? Please???

o2 ?
maf ?


I checked the salt n' pepper shakers. they are fine
 
See less See more
#2 ·
Have you checked your TPS voltage? What about your plugs, wires and distributor cap? Check those first. My car used to stall if i put the clutch in or was just sitting in neutral and i just bumped the idle up a little bit and it cleared right up, idles at 900rpms now.
 
#8 ·
Thanks for the advice guys. It seems like the consensus is in this order:
Timing, fuel pump, fuel injectors.

I may try and adjust the timing. A good google around may teach me how to do that.

Since the fuel pump, and injectors haven't been touched since they were installed in 1989..... if I start to look at those, I might as well upgrade them a little bit!:headbang:

Are the fuel pumps in these cars INSIDE the tank? If so... :banghead:
 
#10 ·
The rest of these answers are probably right but you should check to make sure your butterfly valve at the entrance to your intake moves freely, these symptoms are exactly what the valve is made to compensate for it's kind of like a choke helper. But it could be map sensor, vacuum leak, fuel pump etc as others said
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top