intake air temp sensor, fuel pressure

[andyr354]

Mine reads 124 deg at idle it looks like. Had the scanner on it last night checking sensors. Seems high to me since it was 40 deg in the garage.

The local parts store says they can't get it for a 91 4.0L. Anybody have a part number for it? I don't have a local chrysler dealer anymore so I would prefer ordering it from one of those dealers to sell over the internet. Any suggestions on where to go?

Also I was checking my fuel pressure and just wanted to run these numbers by to see if they sound good.

Idle: 33 psi
Idle with regulator disconnected: 42 psi

I am trying to get everything in good condition to get mileage back up some.

 

[Ecomike]

Mine reads 124 deg at idle it looks like. Had the scanner on it last night checking sensors. Seems high to me since it was 40 deg in the garage.

The local parts store says they can't get it for a 91 4.0L. Anybody have a part number for it? I don't have a local chrysler dealer anymore so I would prefer ordering it from one of those dealers to sell over the internet. Any suggestions on where to go?

Also I was checking my fuel pressure and just wanted to run these numbers by to see if they sound good.

Idle: 33 psi
Idle with regulator disconnected: 42 psi

I am trying to get everything in good condition to get mileage back up some.

The intake air temperature climbs (this is normal) as the engine warms up. I think I have seen mine as high as 145 F with the engine coolant at 165 F (I currently have a non standard 165 F thermostat) after a good warm up drive or very long idle. Not sure what all heats the intake manifold and incoming air but the EGR valve and close proximity to exhaust manifold is part of it.

Your fuel pressure is fine too.

To get the mileage back up I strongly suggest a new O2 sensor. You can test the O2 sensor first. Search this forum for "oxygen sesnor test" for details! Also make sure the O2 sensor wiring harness connector and wire is OK first! They do get damaged on occasion by "close encounters of the exhaust manifold kind".

 

[andyr354]

to many results searching on here.

But google brought these up:
http://www.mr2.com/TEXT/O2_Sensor.html
http://www.forparts.com/o-21.htm

Guess I will get out my propane hand torch and give it a whirl.

 

[Ecomike]

to many results searching on here.

But google brought these up:
http://www.mr2.com/TEXT/O2_Sensor.html
http://www.forparts.com/o-21.htm

Guess I will get out my propane hand torch and give it a whirl.

Be sure and test the sensor installed first with your volt meter while the engine is running!!!!!!! No need to remove it for testing!!!!

 

[andyr354]

yes, they still recommended using a propane enrichment to throw the sensor into the rich condition though.