Car sputters after it runs for 20-30 minutes. Will stall if I dont lift off of gas. If car does stall or I put in neutral, shutoff, and restart it will run like nothing ever happened for a few minutes then start sputtering again.

This is what I have investigated/done

Fuel Pressure good
New Fuel Pump
New Fuel Filter
New Ignition Control Module
Someone has cut off Check Valve for fuel tank (pictured below)



Code 23 from computer
Took off MAF ran exactly the same
MAT/IAT is not hooked up (cant find plug to hook it up)
Do have small lower intake leak (leaking anti freeze)
Do have small leak on fuel rail.
Will get these fixed next week and at that time will check fuel injectors.

Need help!!!!!!!

This is my daily driver!!!!!!!

 

Best thing to do is to get these issues you already know are there, fixed. Then see how it runs. The MAT and IAC need to be hooked up for the computer to be able to run the car correctly. You will need to find these connectors and hook them up. Might be all of what you need.

 

I AGREE YOU NEED THE MAT AND IAC FIND THE WIRES THEY ARE HIDING SOMEWHERE

 

I agree as well. Does anyone have a photo showing where that MAT/IAT plug is suppose to go. Someone told me that it was on the drivers side. Found a plug but it is totally diff from the MAT/IAT plug. I am going to get some photos so you all can see what I am up against. I drove it today and it is very bad off. It sputters from the word go now. Switching it off and back on gets me going for a 1/4 mi or so but if Im not up to speed by then or going downhill I have to switch it off and back on to keep moving. Ill post some photos in a few minutes.

 

OK, in these photos you see the only plug that I could find on the drivers side.

It has a brown wire and a green wire. The brown wire is cut. It has been brought over to the passenger side and spliced into a wire that seems to go down the behind the engine. Cant see where it goes.As you can see the green wire was left with the plug

This harness and engine are from an 88 Formula (L98). It also has the 1988 L98 harness. Could this present a problem?

 

Now for the brown wire that goes over to the passanger side. Cant seem to get the file to upload. Ill try another way to get it on here.

 

That looks like the connector for the washer pump. Not sure what else to think it could be. The intake air temp sensor would have 2 wires and is located under the intake plenum. I will check tomorrow and see what color wires should be there for that sensor.

 

Looking for help. Any folks out there that can chime in?