351GT

So I have not driven my 93 mustang in a year and it is running ruff. It will start, but will die if i don't tap on the throttle. After its warm up it will hold the idle at 900-1100. Though if i drive it around it will backfire out the exhaust and will try and die when I come to a stop.

I have changed both O/2 sensors, oil, oil filter, fuel filter, cap, rotor and pcv valve. I have no codes and my fuel pressure is set at 39psi with the vacuum line off. It is an adj bbk regulator, but no fuel comes out of the vacuum line when I take it off. My fuel pressure gauge goes down slowly when I turn the car off so I think the regulator is fine.

My timing is at 10* and all of my wires are not burned or frayed. I check all of my plugs which are black and tan in color and are gaped at .054 I switched out my mass air meter sensor with another one with no change in how the car is running. So i think the meter is fine.

I have cleaned my air filter, IAC and the TB. It seems like its only is running on 6-7 cylinders on start up. My auto meter a/f gauge says it running rich but I don't have a wide band to certain.

I have check most of my vacuum lines and I don't think I have a vacuum leak. I have a auto meter vacuum gauge and it reads about what it always has in the past.

What else could it be?

94ford5liter

pull off your wires one at a time and see if they are all producing spark. If you pull off a plug and there is no change in how the car idles that can tell you which cylinder is not getting spark. If you pull them off and one or two don't get spark, check if it is sparking on the distributor side, if it is, its bad wires. If not, its either a bad cap and rotor or a bad distributor.

NotchAbove

Bad gas ? If you leave a car sitting for a long period of time, without using dry gas, you could have water in the fuel.

93 LX FiveO

i would start with a new fuel filter.

check for vaccum leaks if problem continues.

ALMOST STOCK

Old gas?

w8less

dont you people have spell check?

351GT

The tank was empty and I put new gas in it.

351GT

I changed the fuel filter yesterday. I checked for vaccum leaks I dont seem to have any. Plus my autometer vaccum gauge holds around 13 in Hg at idle which it always in the past.

I ran another code scan and finally got some codes. With KOER
44
18
13
77

ALMOST STOCK

Code

44 Thermactor Air Injection system inoperative (Right side).
18 SPOUT circuit open or spark angle word failure.
13 Cannot control RPM during ER Self-Test low RPM check.
77 System failed to recognize brief WOT during Dynamic Response Test (user error).

351GT

So should I start by putting in a new TFI module?