2.3L ('83-'97) 88 Ford Ranger Only runs with Airbox disconnected

[OneEyedDog]

Hey all, new here but hoping for some insight as I've already thrown a bunch of parts at this new little project of mine.
1988 Ford Ranger 2.3 with a 5spd manual.
Title says it all basically. I've replaced a bunch of parts trying to chase this no start gremlin including, solenoid, starter switch, and ignition control module. But recently discovered it just refuses to start without the airbox disconnected. Even then it obviously idles extremely high (1500 rpm) from running lean so it's not a fix to keep it disconnected. I looked at the idle air control and tested it by disconnecting it (it starts to bog down so I assume that means it's alright if what others on the forum have said is true) any suggestions are really appreciated and thank you all for the help

 

[franklin2]

The airbox physically disconnected or just electrically disconnected? Not sure what your year engine has, mass air? Or a air vane? Air intake temp sensor in there too somewhere?

 

[OneEyedDog]

The airbox physically disconnected or just electrically disconnected? Not sure what your year engine has, mass air? Or a air vane? Air intake temp sensor in there too somewhere?

Just physically disconnected, without the IAC plugged in it bogs down and barely runs. I believe it may have the mass airflow sensor on the throttle body. Edit: looking at O'Reilly's it seems it has a air intake temp sensor

 

[scotts90ranger]

An '88 is speed density, just a map sensor in the cowl or mounted to the cowl so the air box being disconnected should make no difference. that alone doesn't make it run lean or anything, shouldn't care...

If it bogs down and barely runs with the IAC disconnected but idles high with it connected then the IAC is working but something isn't working right, check the vacuum hose to the MAP sensor, might be mounted in the cowl just above the heater hoses I think, aside from the green and red vacuum lines going to the EGR should be about the only vacuum lines in that area

 

[RonD]

On the air box do you see a 4 wire plug on a metal tube, that would be a MAF sensor
2 wire connector on the air box can be air temp(IAT or ACT) sensor
1988 2.3l should still run MAP sensor not MAF sensor

At the bottom of the air box, under the filter, is the Cold Air Intake(CAI) tube
It runs to a hole in the Rad support to pull in air from behind the grill

Also on this CAI tube, in the engine bay, is the air pre-heater setup, it was often removed after engine work, lol
It has a flap, a vacuum operated flap, that would close on cold start to pull in air from around the exhaust manifold, warmed air, to help engine to warm up faster

Obviously if this CAI tube is blocked in any way engine can not pull in air thru the filter and into the engine, so won't run

 

[OneEyedDog]

On the air box do you see a 4 wire plug on a metal tube, that would be a MAF sensor
2 wire connector on the air box can be air temp(IAT or ACT) sensor
1988 2.3l should still run MAP sensor not MAF sensor

At the bottom of the air box, under the filter, is the Cold Air Intake(CAI) tube
It runs to a hole in the Rad support to pull in air from behind the grill

Also on this CAI tube, in the engine bay, is the air pre-heater setup, it was often removed after engine work, lol
It has a flap, a vacuum operated flap, that would close on cold start to pull in air from around the exhaust manifold, warmed air, to help engine to warm up faster

Obviously if this CAI tube is blocked in any way engine can not pull in air thru the filter and into the engine, so won't run

I removed the airbox and looked for the CAI and yeah its just gone on the ranger, should I look for a new one?

 

[OneEyedDog]

An '88 is speed density, just a map sensor in the cowl or mounted to the cowl so the air box being disconnected should make no difference. that alone doesn't make it run lean or anything, shouldn't care...

If it bogs down and barely runs with the IAC disconnected but idles high with it connected then the IAC is working but something isn't working right, check the vacuum hose to the MAP sensor, might be mounted in the cowl just above the heater hoses I think, aside from the green and red vacuum lines going to the EGR should be about the only vacuum lines in that area

I'll give it a look around and make posts on any new discoveries I make, thank you

 

[RonD]

Its just sucking in air from engine bay if tube is gone but shouldn't cause engine to stall
Cold air intakes give you a bit more power after warm up, not a lot but not 0 either, lol
So whether or not you add it back is up to you

 

[scotts90ranger]

There was no MAF sensor on a 2.3L until mid '90 model year, so don't even think about that sensor since you don't have one.

 

[OneEyedDog]

There was no MAF sensor on a 2.3L until mid '90 model year, so don't even think about that sensor since you don't have one.

Yeah I can confirm it's a MAP sensor as I replaced that as well

 

[scotts90ranger]

Is the hose intact from the MAP sensor to the intake manifold? Are there any trouble codes? go HERE to find out how if you don't know how, if you have a check engine light that will flash just like the analog volt meter or test light will.

 

[OneEyedDog]

Is the hose intact from the MAP sensor to the intake manifold? Are there any trouble codes? go HERE to find out how if you don't know how, if you have a check engine light that will flash just like the analog volt meter or test light will.

MAP hose is fresh, I'll try and pull some codes here in a bit and have them posted