Engine hesitation/ random engine shutdown

[USMCSurvivalist]

2003 Explorer XLT 4.0 4wd

I have an issue where I can feel and see my engine hesitating. It doesn't show up on the RPM gauge but almost at an interval I can feel it shake. Once in a blue moon when I back out of a parking space as I hit the brakes the engine will die. The other day coming to a red light when I stopped the engine died too. Hasn't die in about 6 weeks but the hesitation is still there. Replaced the frozen ac compressor a couple weeks ago, and also both upstream 02 sensors after it threw a code for bank 1 fuel trim to rich and bank 2 upstream O2 sensor bad. Had a fuel system/ injector clean done when they were recharging the AC and it was blowing carbon out the tail pipe, it seemed to run better after that for about a day (could be in my head) but now the hesitation is back, I start it up and can feel the intermittent Engine shake. Any Ideas?

 

[Bobmbx]

First thing to do is clean the IAC. Low speed (idle) stalls are most likely caused by a dirty IAC. How many miles on the Exp?

 

[USMCSurvivalist]

It has a little over 165,000. Would it be best to just outright replace it, Orielly Auto has Motorcraft IAC valves for 67 dollars and I have a few coupons as well.

 

[USMCSurvivalist]

So I removed the IAC and replaced it with a new one from O'REILLY Auto for 33 bucks, new gasket and all. Cleaned the harness contacts with some electrical cleaner. The old one had a nice layer of build up on it, I cleaned out the intake holes with carb cleaner and wipes them out.

I did notice something else that bothers me and may be a contributing factor. The hoses going to the EVAP Purge Valve are starting to crumble apart, i can rub them and its like layers coming off, im sure with little effort I can scratch through them.

 

[USMCSurvivalist]

Most of the black on my hands is actually from the EVAP hoses. You canmot see any markings any more on the lines.

 

[Bobmbx]

So I removed the IAC and replaced it with a new one from O'REILLY Auto for 33 bucks, new gasket and all. Cleaned the harness contacts with some electrical cleaner. The old one had a nice layer of build up on it, I cleaned out the intake holes with carb cleaner and wipes them out.

I did notice something else that bothers me and may be a contributing factor. The hoses going to the EVAP Purge Valve are starting to crumble apart, i can rub them and its like layers coming off, im sure with little effort I can scratch through them.

Thats dry rot. They'll be ok until you disturb them. That kind of hose is cheap enough to just figure out what sizes and lengths you need, and then help yourself to some new hoses. While you're doing that, you'll acquire intimate knowledge of your engine vacuum controls.

Did the new IAC fix your original problem?

 

[USMCSurvivalist]

Im gonna leave the battery cable disconnected till morning

 

[USMCSurvivalist]

Well the new IAC was bad, waiting on a new one. Sprayed out the old one but doesnt seem to do much for the idle. Sprayed carb cleaner around the engine looking for leaks, engine never revved up so I think we are ok there.

 

[ExcursionMJ]

You got a bank 1 and bank 2 code? I'd bet that you have a bad mass air flow sensor.

 

[USMCSurvivalist]

It was bank 1( pass side) fuel trim and bank 2 o2 sensor. Replaced both up stream 02 sensors. It had a check engine light for like two day and went away never came back. Pulled codes and thats what I got. Opted to do both 02 sensor because they were relativly cheap.