Plz Help! ‘88 Mustang will not idle and runs poorly

88foxxxx

Member
Mar 16, 2020
3
1
13
27
Kingsport, TN
Hey guys. I’ve got an 88 Foxbody that I purchased a few months ago. The car ran alright but just didn’t seem to be getting enough air. So I ended up coverting to Mass Air and used the proper comp (A9L), but once I started the car it wouldn’t run with the meter hooked up. Ended up getting the ECU tested and it’s good, replaced IACV and ran the #s on the injectors to make sure they were 19s. They were mixed and matched from the idiot prior to me so I replaced them with a set of 19lb injectors but once I put the car back together, it still doesn’t want to idle or run. It will start up fine, idle for just a few seconds, and cut right back off. I can give it gas to keep running but it seems muffled. I’m beginning to wonder if it’s possible that O2 sensors might cause these types of issues. Any input would be great!
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
Ok, first the basics (I always revert to basics) because of unknown stuff previous owners do/do not do.
Make sure plugs, wires and distributor cap are in good working order.
Check the timing, make sure the pointer on the balancer is at 0 when the #1 piston is at top dead center then check your timing with a timing light 10-12* btdc is a good place to start.
You did take the vacuum line off the sensor on the firewall as instructed when converting to mass air?
After you verify those things and still have problems go to the 'surging idle checklist ' here is a link:
 

88foxxxx

Member
Mar 16, 2020
3
1
13
27
Kingsport, TN
Ok, first the basics (I always revert to basics) because of unknown stuff previous owners do/do not do.
Make sure plugs, wires and distributor cap are in good working order.
Check the timing, make sure the pointer on the balancer is at 0 when the #1 piston is at top dead center then check your timing with a timing light 10-12* btdc is a good place to start.
You did take the vacuum line off the sensor on the firewall as instructed when converting to mass air?
After you verify those things and still have problems go to the 'surging idle checklist ' here is a link:
I’ve got the timing set at 0 at TDC, I just need to use the timing light to get it between 10-12. And yes, I did unplug the vacuum line when doing the conversion. I will try to put a timing light on tomorrow and get that dialed in, and start going down this checklist. Thanks for the input!
 
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