Idle and driving issue, possibly weather related?

[mclarenf1kid]

I spent almost 2 hours last night reading on threads pertaining to my issue, and couldn't find a straight answer. So here it goes:

All my problems have been since it started getting very cold here in Spartanburg, South Carolina.

My Explorer has been running PERFECT since I bought, with the reg. maintenance done.

Yesterday, I drove it to work, ran great.

Went to leave for lunch. Started fine. Got down to the road to the stop sign. Pressed the gas, and it did nothing for a second before the gas kicked in and it finally drove.

Once driving, it was fine.

Got ready to turn onto the main highway from a stop. Pressed the gas, only this time, it cut off. From that point, it would not start again. It would turn over, but not start.

Pushed it off the road, left it in a parking lot, walked back to work.

When I got off work, went back to the Explorer (5 hours later), started right up.

Driving home, got to another stop sign, did the same thing. Press the gas, and it cut off. Wouldn't start for another 15min. Idle was incredibly rough, like it wanted to die. Driving it home, didn't feel much loss in power, just a lot of hesitation.

Got it home.

Replaced the fuel filter. Didn't help. Same idle and cut off issues.

Jumped on here and did some research, and now I'm trying to narrow this down:

- Won't crank up, but turns over, which means fuel issue. Fuel pump turns on and works, since once it runs, it drives fine. Fuel came out of lines when I did the fuel filter. Fuel Pressure Regulator?

- Idle is incredibly rough. Idle air valve?

- When you press the gas, it dies, unless you go WOT. MAF?

- Temp gauge never reaches half way (been like this since I bought the truck, but runs and drives great, no overheating). Possible Temp sensor?

- Fuel in exhaust when revved (obviously running rich). O2 sensors?

Based on my symptoms, won't crank up, once running dies when pressing gas, rough idle, running rich, dumping fuel, I can't seem to narrow it down.

Thoughts? Weather related?

 

[MrShorty]

1st thing I would probably do: after running the engine, pull the vacuum line to the fuel pressure regulator and see if there's any gas in that vacuum line. Any gas=bad FPR.

If that test of the FPR checks out, then I might hook up a fuel pressure gauge and test the fuel system (refer to our "fuel pressure mini-diary" in the under the hood forum).

Then I'd probably pull codes to see if the computer can shed any light on the issue.

 

[mclarenf1kid]

Ah, good tip on the FPR. Crossing fingers for that; hoping an easy fix.

 

[92exp4x4]

Pull codes. I have seen two PCMs in the last week with internal power circut failures on this forum. The PCM controls the ground to the fuel pump relay and this can cause your problem; or a complete no-start. Check the relay and connections too.

Let us know what you find.

 

[mclarenf1kid]

WELL lol,

Checked the vacuum line to the FPR and no fuel, which tell me its fine.

HOWEVER, oh just my luck.....

Installed the FPR, checked my fluids.....coolant res and rad were dry. Went to top it off and coolant came pouring out of the block.....from the missing freeze plug port.

Truck must have overheated (obviously). What's strange is that my needle never went up. It moved just passed the C, but never got to hot. Would the temp needle move even with a bad temp sensor?

I'm PRAYING I don't have any internal damage!

 

[mclarenf1kid]

It's fixed!!!!!

Now keep in mind all the symptoms above......

......were fixed by replacing the thermostat?!!!!!

So,

Tested the FPR and it was good. Fuel pressure was good from the schrader valve. New fuel filter. Fuel pump was good. I had ruled out fuel.

Topped up my fluids and started her back up. Same rough idle after letting her idle for about 10min. Put my heat on to find no heat from the vents.

Thermostat.

Pulled the thermostat to find it was rusted as hell. Hence the overheating, hence the freeze plug popping out.

Replaced that, topped off my fluids, started her back up....

Perfect!!!!! Smooth idle, test drove showed consistent power, couldn't be happier.

BUT....

Now I don't have any heat! I had heat before; but that could have been heat from the motor overheating.

New thermostat, hoses are nice and hot, indicating good coolant flow, new water pump. Gonna check the heater core hoses when I get home, hopefully they are cool, indicating an easy fix.

Nevertheless, she runs again!

 

[runderwo]

Back flush the heater core. If your thermostat was "rusted", there is probably all sorts of corrosion in there.