88 GT wont idle.... help please

[88mustang50]

i have a 88 mustang Gt that is a Speed Density car.

i have cleaned the idle air control valve, got a new EGR Valve, checked the hoses (all good) checked the Throttle position sensor, got all new gaskets for the intake manifold (except for the upper to lower), i have new plugs and wires, cleaned the intake and changed the oil.

i do not have O2 sensors, don't know how to clean the Map sensor, have an exhaust leak b/c i have sn95 headers that the egr pipe was cut and pinched, have not replaced the PVC valve grommet or screen, and i do not have any of the egr parts that come from the smog pump or really any of the egr except the egr valve.

can you please help me and give me clues or "how to" info to fix this?

 

[superstroke17]

I'm not 100% certain but i think u need o2 sensors. I've never removed them so honestly dont know what happens. But i do know if one hits the deck your car will run like garbage. If thats any help, but yeah my car had some serious idleing issues after i removed my smog system. It is also a speed density car. But I really cant help u cause mine still idles like ****, but i'd say it may be the O2 sensors or the IAC. But anyway good luck!! There's some smart people here and someone will help u out!!

 

[superstroke17]

You can also do a search on this. There is a surging idle check list on here that is very helpful. Oh yeah and welcome to stangnet.

 

[Mustang5L5]

ii do not have O2 sensors, don't know how to clean the Map sensor, have an exhaust leak b/c i have sn95 headers that the egr pipe was cut and pinched, have not replaced the PVC valve grommet or screen, and i do not have any of the egr parts that come from the smog pump or really any of the egr except the egr valve.

can you please help me and give me clues or "how to" info to fix this?

I think you pretty much gave yourself clues.


You need 02 sensors.

Missing most of the EGR system may also lend a role in the surge.

 

[88mustang50]

where can i buy the rest of the EGR equipment?

 

[jrichker]

See the "Surging Idle Checklist for help with all your idle/stall problems. The first two posts contain all the updates to the fixes. I continue to update it as more people post fixes or ask questions.

 

[88mustang50]

now i have new O2 sensors. it idles better but the when i try to drive it dies.
now it idles at 500rpms.

 

[HISSIN50]

Clear the KAM, drive it and pull codes again.

 

[88mustang50]

KAM? i dont know what that is.

 

[Mustang5L5]

now i have new O2 sensors. it idles better but the when i try to drive it dies.
now it idles at 500rpms.

Reset the computer, unplug the IAC and perform an idle reset by adjusting the idle to 500RPM with the IAC unplugged. Then reset the computer again, plug the IAC in and start the car.

Allow a few mins to learn idle strategy.



Then pull the codes

 

[irish]

If you have an exhaust leak before the 02 sensors, you won't be able to make it idle normally. The 02 sensor will read more air than was counted on and the ecu will constantly be adjusting the air fuel mixture giving you a rolling idle. Ditto if you have a leak in one of your vacumn lines/intake gaskets.

Replace the pcv stuff its really inexpensive, is the cam in the car stock?

Matt

 

[88mustang50]

If you have an exhaust leak before the 02 sensors, you won't be able to make it idle normally. The 02 sensor will read more air than was counted on and the ecu will constantly be adjusting the air fuel mixture giving you a rolling idle. Ditto if you have a leak in one of your vacumn lines/intake gaskets.

Replace the pcv stuff its really inexpensive, is the cam in the car stock?

Matt

the cam is stock that i know of....?...... previous owner said it was but he lied about a lot of stuff.
and yeah i have the pvc valve but i had to order the grommet and screen and will replace that on Tuesday.
it has that leak in the headers where the egr pipe was cut and pinched its small but there. that will effect it that much??

 

[88mustang50]

Reset the computer, unplug the IAC and perform an idle reset by adjusting the idle to 500RPM with the IAC unplugged. Then reset the computer again, plug the IAC in and start the car.

Allow a few mins to learn idle strategy.



Then pull the codes

how do i adjust idle??

sorry new to this.

 

[88mustang50]

Reset the computer, unplug the IAC and perform an idle reset by adjusting the idle to 500RPM with the IAC unplugged. Then reset the computer again, plug the IAC in and start the car.

Allow a few mins to learn idle strategy.



Then pull the codes

NVM i got it!!
and thank you it helped it not die!!!
but it still lopes horribly when warm.

but i can drive it at least.

 

[jrichker]

You have gotten some good advice here. However, if you want to find all of the cures for idle problems, click on this link "Surging Idle Checklist. In the first two posts are all of the common problem causes, along with descriptions on how to find and fix your problem.

 

[Mustang5L5]

NVM i got it!!
and thank you it helped it not die!!!
but it still lopes horribly when warm.

but i can drive it at least.

What was it?

 

[88mustang50]

What was it?

idle was set to low.
and after all i did to it i never reset the computer.

 

[88mustang50]

You have gotten some good advice here. However, if you want to find all of the cures for idle problems, click on this link "Surging Idle Checklist. In the first two posts are all of the common problem causes, along with descriptions on how to find and fix your problem.

I did and thank you alot!!!!

 

[88mustang50]

i replaced the PVC and the upper to lower head gaskets and still nothing. it sounds smoother but still bad idle lope after it gets warm.

 

[88mustang50]

Does anyone have any other ideas or experience on this???
i when threw that check list and its all still the same.