So my truck died and won't start backup. Anyone know whats wrong? Kidding, heres the info behind it... I have a '99 PS F250, SC, Auto, 4x4. About 3 months ago the truck started to have this very intermittant hesitation where it felt like the fuel injectors shutoff for about half a second or less while driving but then come right back. Full power all the time except for the momentary hesitation. About a month ago it stalled at a traffic light but started right back up. Then it was very intermittant where it felt like more and more it was stalling out and most of the time would come back before a complete stall but sometimes would stall. My first thought was the CPS. I changed it when I bought the truck (don't know what color) at 130k miles and now that I'm at 210k I thought I would bring it to Ford to have them do the official recall. Got the truck back on Friday and no change. Hesitation/Stalling is still there. Yesterday on my way to work the truck stalled while driving and I pulled off and it wouldn't start back up again for the first time. Leaving it in a parking lot to get later, my dad tried starting at noon with no luck but then I tried it at 5 pm and it did start and I was able to drive it 5 miles home. I read about the 50 cent mod but don't think that's my problem because it seems to be an 'all or nothing' deal with the fuel injectors since I either have full power or no power on both banks. Doubt it's the CPS because I had it changed with no change in the problem. Any other ideas? I'm going to put a code scanner on it tonight or tomorrow to see if there is anything there. No check engine light. Hopefully this gets the ball rolling. I appreciate any ideas in advance. I love the tips you guys give when reading about other peoples problems, always hoping it wouldn't be me. I also need to research preventative maintenance to do on a high mileage PS, but i'll save that for later. Thanks again.

 

man it sound almost excatly like my truck when the cps went out. electral parts are not always good out the box. i would try another just to be sure. good luck to you. where are you at? and do you need a tow?

 

It is Spring time. Is the weather dry or wet where you are at. When my CPS was giving me problems (truck dies) it only happened when I went through a large water area and it was raining. Moisture was getting into the electrical areas of the CPS. Either around the seal going into the block or the plug in. Take your CPS out and clean it up and put some electrical grease on the rubber seal and the rubber where it plugs in.

You should also have a code stored that you can pull up.

 

CPS is a good start.

Might want to pull you ICP sensor plug and see if it has oil on it, if it does, try leaving ICP unplugged and go for a ride and see if problem goes away. I am waiting on a ICP sensor from Riffraff right now for my buddies late 99, same symptoms diagnosed just last weekend.

 

Since you brought up the icp"go for a ride and see how it does" I've tried this and the truck ran good at first them just started falling on it's face and thought it wouldn't make it back to the shop. Shoul it run just fine or is this more like a leave it at idle kind of test?

 

I am not sure on a modded truck, but my buddies stock truck has been running just fine all week with it unplugged, it is using the default ICP parameters/tables when unplugged.

 

The reason I ask is cause my truck smokes real bad and I'd be scared to even drive it down the road.

 

Not sure on your truck, what mods do you have? My buddy has logged over 700 miles since we unplugged his last weekend, just runs like a stock truck, I just called him to confirm.

 

Just wondering if this has anything to do with my truck being so slow. It's a current thread"Trucks a turd!"

 

Thanks for the ideas. I didn't think it was the CPS because of how similiar it was after the CPS was changed Friday, but maybe I'll try a new one. What color should the new one be? I'll try the ICP unplugged tonight and see what happens along with checking for codes. I'll keep you posted, thanks for the help...

 

Ok, so the truck is Fixed! Thank you so much for the feedback, heres my update. Checked the ICP like you guys mentioned and sure enough when I unplugged it the connector was soaked in oil. I thought this was the problem so I left it unplugged, cleaned it, and started the truck. Within a few minutes and a stall I could tell there was no change in the problem. Then I ohmed out the two plugs that go into the valve covers and discovered that all fuel injectors read identical at .3 ohms. Unfortunatley I found that only 2 glow plugs seemed to work which now explains why it's a bear to start in the cold, but that's a separate issue.

So then I went to my wiring diagram book that I got from Ford and started working backwords. It showed a relay that *edit: 'powers up the'* Injector Driver Module (IDM). With the truck running I just touched that relay and it stalled. I swapped it with the blower motor relay (same p/n) and let the truck run for a good 15 minutes with no sign of the problem, took it for a ride and no hesitation/stalling. I guess there is always a chance it's the socket to that relay, but i haven't had the problem come back yet so i'm pretty confident with the fix. Now it's time to get another relay for a spare, a new ICP sensor, and new glowplugs, but at least i'm not dead with no truck! Thanks again everyone and hope this little bit of info helps someone else...

 

Thanks for the update. Nice to know the fixes that are found. Lee