bizzare runnung problem

dennis2 · 08-25-2009, 10:33 AM

99 expedition.... Intermittantly at a stop after warning up the temp and oil gauge spike out, and the engine runs like crap. Hard pressed to get over 20 mph. Pull over, shut down. Not leaks rad overflow full, oil level fine. Restart and all is well. Happened 2-3 times now. Before I start replacing sensors is this a common problem????? Thanks Dennis

TBIRD430 · 08-25-2009, 02:01 PM

Start with a new fuel filter & a can of Seafoam brand fuel treament in the gas tank for the idle problem. I'm not sure about your gauges though, could be related I guess...

dennis2 · 08-25-2009, 02:16 PM

Quote:

Originally Posted by TBIRD430

Start with a new fuel filter & a can of Seafoam brand fuel treament in the gas tank for the idle problem. I'm sure about your gauges though, could be related I guess...

They rough run only happens when the guages spike out. Or are you saying the rough idle(fuel filter), may be the cause of the temp/oil gauge spike?

BroncoJoe19 · 08-26-2009, 05:15 AM

Definitely not a common problem.

They'll spike when they are shorted to ground.

WHen the short occurs, Could be that the PCM then reads an overheated engine, and cuts half of the fuel injectors, so the engine runs like crap.

dennis2 · 08-26-2009, 06:41 AM

Quote:

Originally Posted by BroncoJoe19

Definitely not a common problem.

They'll spike when they are shorted to ground.

WHen the short occurs, Could be that the PCM then reads an overheated engine, and cuts half of the fuel injectors, so the engine runs like crap.

Shorting to ground as in a possibly bad sensor ? Being intermittant I guess it could the sensor or a ground wire issue. Is the ground common for the temp and oil sensors?

This is my Daughters truck. I'll be heading down to hopefully repair this weekend. She doesn't have a service manual and tells me the local auto stores don't have a haynes for it. I'll check local for one

TBIRD430 · 08-26-2009, 02:19 PM

Quote:

Originally Posted by dennis2

They rough run only happens when the guages spike out. Or are you saying the rough idle(fuel filter), may be the cause of the temp/oil gauge spike?

Sorry for the mis-cue. I edited my original post above.

I'm thinking a fuel filter getting clogged/restricted (when you need more gas to the engine) and cutting the engine out would NOT be related to your dash gauges 'pegging out or spiking'.

I replace fuel filters annually or every 12-15K on our vehicles (if they have a servicable one). They are cheep enough anyways, and I didn't know when yours had been replaced last....