99 7.3 tries to start, but won't turn over...

[DukeDuke]

I read the threads below, but none seemed to compare....

A month or so ago, I started my truck and waited for the WTS light to go off, and then started it, it seemed to take longer than usually to turn over, it happened for a few days then went away. It started back day before yesterday and then when I left work yesterday again took a while to turn over, but did, drove home, appx ~7 miles, was cleaning out my truck and the girlfriends Jeep, went to run to the store and truck wouldn't turn over again, just the rawwr rawwr rawwr rawwr like it was trying to, all the pressure on the tachs went to their normal location, but didn't turn over.

This morning I ran out there hoping to move the truck to get one of the other cars out to drive to work, and it started right up, but with the delayed turn over.

A buddy mentioned possible Cam Shaft Sensor(I think that's what he said? Apparently a real big issue with the Powerstrokes) does anyone else have any ideas? Thanks!

Bought it 7 months ago, with a brand new started, and two new batteries, if that helps anyone out at all...

[NoRalPh]

First, and I'm sure this is just a regional difference, but to me,,,, your truck IS "Turning Over" just fine - right? The problem is it's Only on the starter

As I said, just want to be clear the engine "turns over" but just won't Start. When you say it just goes "rawwr rawwr rawwr rawwr" that noise is the starter but, the engine is turning, the fan would be going around at the same time....... right?

So, a couple of things, the CPS is a common issue BUT with your year truck, tach movement while cranking is an indication the CPS is working (that's where the tach gets its rotational signal from).

The next good news is the WTS light, you've got one so it's an indication the PCM is running.

This morning it started, but cranked for a longer time than usual?

Does it seem to be more likely to happen when hot than cold?

There's a bunch of things it could be of course, but there's nothing worse than an intermittent problem until the bad part finally fails completely. If you had the right kind of equipment you could monitor the trucks systems to see which it out of spec and narrow it down.

Without that, take a good look at a couple of things, The ICP sensor can be fluky and a good indication of that is oil leaking through it and into the connector. Pull the connector and have a look next time it does it. If the ICP is the problem it will start right up because the PCM will ignore the bad reading and substitute a "limp" setting. Clean the connector and look again in a couple of days for fresh oil.

The IPR could be failing and you can, at least, check the connector for corrosion and tightness as well as the tin nut being loose on the coil...

You should also listen for the fuel pump to be running for a couple of seconds when you first roll-on the key (on the frame rail, under the drivers seat) each time you start to see if there's no sound when it isn't starting for you.

Another thing, forget the time the WTS is on, it's no indication of how long the GlowPlugs are on. If you're having trouble, especially if it's cold out, wait an additional 30sec to a min After it goes off to see if it helps...

OK there's a start (I'm out of ideas ) but, in the end, a proper scanner (most here are fans of the AutoEnginuity, a Great all around tool) would be the fastest way to know

[Camoderek]

Where is icp on 7.3?

[NoRalPh]

Originally Posted by Camoderek

Where is icp on 7.3?

Do you not see the attached picture in my previous post?

Maybe not, I see your other post and you're Stuck on the road.... The ICP is the sensor at the front of the drivers side head, in towards the center of the valley, close to the fuel bowl below the hard lines that go to the bowl (hope that helps....)

[DukeDuke]

Sorry for the delayed response. I finally got a chance to get out there and work on it yesterday. The ICP did in fact have a lot of oil in it. I cleaned it out really well, and it would crank over and over and over again just fine. Last night I went out for a buddies bachelor party and drove the truck, went to leave an hour or so later to go somewhere else, and it wouldn't start again. Same thing, just the raawr raaaawr raaaaawr. I came back about 5 hours later after and it started up fine. Does this in fact point to the ICP being bad? How hard is it to replace? How much does it cost? I looked at the IPR as well, no corrosion or anything, only thing is the rubber gasket around it looked worn, do they sell just that gasket?

[NoRalPh]

No, no, don't go and BUY anything

First, the oil in the connector is Not what would be preventing it from starting, it's just an indication the seals in the sensor are bad. UNPLUGGING it will "override" the wrong pressures it might be sending to the PCM. So, if it won't start and you just unplug it and it Does then start (maybe have it happen a couple of times to be sure) Then, you could call the ICP bad.

BUT, ultimately, you should get a good scanner on it to know more about what's going on,,,,

I wouldn't worry about a "worn" gasket unless it was leaking something it was supposed to hold in

[DukeDuke]

So I have finally been able to drive it around enough to get it to have a problem and not turn over. And I got to where I could try to wipe the ICP clean and then see if it would start, and it made no difference. Here is an awful video I took of it last night, doubt it will help but here it is... Again sorry about the bad quality.

YouTube - 99 F250 7.3l diesel won't turn over.

YouTube - 99 F250 7.3l diesel won't turn over.

[justinlogue5_0]

It was hard to tell in your video but while you were doing all that cranking,was the tach moving? If not, thats pointing to a bad CPS(cam positioning Sensor). One more thing. what NoRalPh was telling you is, The next time it doesn't start UNPLUG the ICP and see if it cranks. Don't worry about cleaning it and putting back on,leave it unplugged while cranking it. If it cranks do this same step a couple times to see if starts up every time you unplug it. If so it points to a bad ICP sensor.

When you crank on it during the day does it put out any smoke?

[DukeDuke]

OOOOH OK! Yeah I am sorry about the video, I was trying to manage to show tach movement. It did go to its normal locations. It is also smoking a very white/blue smoke. The longer I have to crank it to get it to turn over, the more smoke there is.

[justinlogue5_0]

Ok, Now let us know what happens when you unplug the sensor on the next no start.