Ford Mustang Forum banner
Cancel

1989 mustang lx supttering, poping..ect.

992 Views 10 Replies 5 Participants Last post by  90 stock stang, 
proracer70
i have a 1989 mustang which stutters/sputters and back fires and pops out of the intake and exhaust, and bucks and kicks. mostly when the car is cold but sometimes it does it whenever. ive check/replaced iac, broken/worn vacume lines, full tuneup, and i have had no diffrence at all! and i have another annyoing problome on top of that, it will idle any where form 1600-2900 rpm! but if i turn the car off then on again it will be fine till it randomly starts acting up again. somebody told me maybe an intake gasket leak, another told me its the fuel pump, i dont know what to think or do but its to the point where my car is barley driveable. also my exhaust smells rich. i have a FPR and i have no idea what it is set at becuase i dont have a fuel pressure gauge to check and i woudlent know where to mount it.
Save
Like
Status
Not open for further replies.
1 - 11 of 11 Posts
EagleAutosports
Sounds like a vacuum leak to me. It could be a line popped off, or one dry rotted and split, cracked, or a hard plastic line broke. That would cause the air fuel to be way off and cause the smell you have.
If you wanted to get a gauge for the fuel pressure, you'd take out the schrader valve out of the fuel line right behind the alternator and install it there. It'd have to be stainless if you intend on leaving it there, or to temporarily check the pressure and then remove it, you could get a brass gauge. Brass just can't take the constant pressure that stainless can.
Save
Like
proracer70
what would explaine the random high idle? random!!! and the fact when it is at high idle, and its in gear its like i have a cruise control its so annoying.
Save
Like
C
i had the same prob..with idle, it turned out to be the tps!
Save
Like
C
Also mine was poping to...because of all the parts i put on and did not tune it right...i had a maf on witch was not calibrated for cold air intake and my timing needed to be bumped up a few degrees...don't know if this will help.
Save
Like
proracer70
well i do have a cold/ram air set up with a k&n on it. and my tps green wire is kinda beat up from me poking at it to set the tps. could it be a bad ground because the ground wire from the drivers side head is like hanging off , so i connected it to another ground but kinda hack job like. any other ideas? would bad o2 sensors do this?
Save
Like
proracer70
ok, i got an update, i got a can of carb cleaner and sprayed like the whole engine bay and nothing effected anything, i cleand the maf and cleand the throttle body and nothing at all of a diffrence. same bucking and stuff but the worst thing is the random high idle ranging from 1200-2900! anybody have anything to help me out with. ill deal with the bucking but the idle is just stupid.
Save
Like
R
That is the exact some problem I am having. I don't want to just start throwing parts at it. I am thinking it is possibly the o2 sensors. The reason I day this is because recently my heater core went and it leaked coolant and it dripped all over my o2 sensor. Ever since then it has been running like ****.
Save
Like
proracer70
becides the 02 sensors and the eletrictal, i have checked EVERYTHING, i recently bought a can of carb cleaner and sprayed everything and nothing was wrong with any leaks, i check all the injectors with a long piece of skinny rebar and they all are working properly, so its either a bad ground or 02 sensors.
Save
Like
proracer70
ridebmxalot said:
That is the exact some problem I am having. I don't want to just start throwing parts at it. I am thinking it is possibly the o2 sensors. The reason I day this is because recently my heater core went and it leaked coolant and it dripped all over my o2 sensor. Ever since then it has been running like ****.
Click to expand...

did your car run rich? because mine does and i did check fuel pressure and tps and my exhaust still smells rich, the 02 sensors do look pretty old.
Save
Like
9
Maybe the green wire on the tps has corrosion on the wires but you cannot see it through the insulation on the wire.
Save
Like
1 - 11 of 11 Posts
Status
Not open for further replies.
Ford Mustang Forum
A forum community dedicated to Ford Mustang owners and enthusiasts. Come join the discussion about performance, builds, modifications, reviews, engine swaps, classifieds, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
2005-2010 Mustang Talk 2011-2014 Mustang Talk 5.0L Tech Classic Tech 2005-2010 Mustang GT Tech
Top