98.5 24V
problems started about 3 months ago- occasionally, it would "hiccup" for a second or so, then it would be fine. I assumed that it was bad fuel, as I was geting it from a smaller gas station that obviously doesn't move a lot of diesel fuel. This intermittent problem persisted every time I got fuel there, but seemed to go away with fuel from other stations, so I concluded that it was most likely water in the fuel.
So, last night, on our way home, it did this again, more abruptly, 3 or 4 times within a mile. The tach also lost signal several times, even with the engine still running. I pulled over, and waited a few minuted, and it restarted, but I was unable to drive faster than about 20 mph. I went about 200 yards, and it died again, this time for good.
here is what I have found so far- I changed the fuel filter today, it was nasty. Still no start. I took one of the plugs out of the filter housing, and turned the key on. No fuel. I assume that the LP is dead, but what about the tach signal? I read on here somewhere about the crank sensor feeding the tach, and that with a bad crank sensor, the LP won't work.
I figure before I throw any money at it, I should check the codes. Is there a way to retrieve the codes on the odometer? I don't have access to a code reader, and I would rather not pay another tow bill just to take it somewhere to have the codes read.
HELP! this couldn't come at a worse time- my wife's Jeep is down too, and we are down to one vehicle. If I can fairly easily diagnose and fix the truck, I would like to start there first. The Jeep is an intake gasket, wich is a major pita.

sorry for the realy long first post.

 

Try turning the key on and off three times and leave it on the third time. This will not work for a 99 but I'm not sure about a 98.5. I would suggest getting an OBDII scanner from a parts store. They are worth the investment. Next, get a fuel pressure guage installed. If you took a plug out and you are not getting fuel to the filter, your lp is shot. As far as the tach is concerned, there could be two things (lp and sensor) wrong with your truck at the same time. There's no law that says only one thing at a time can fail. Now if your lp is shot and you have been driving the truck with the IP pulling it's own supply of fuel, I would expect to see some IP codes coming along soon.

 

Start with the Key in the off position, cycle to run and back to off, Do this 3 times on the third time leave the key in the run position and the codes will be displayed, After it says PCM DONE its really not done, you may get another code or two out of it. With out a functioning crank sensor more importantly the truck will not operate period, if you bump the key, you should hear the lift pump no matter what codes are present.
Heres a link for the DTC's

http://www.turbodieselregister.com/I...OBDIICodes.pdf
Pm me if you have other questions
Scott

 

Ohh by the way, welcome to the site. There's alot of good info here and the folks are really helpfull. Let us know what you find out.

 

98.5 and 99 do not have the key on DTC display feature that the 00 and up trucks have....the only way to retrieve DTC's is with a code reader or scanner, unfortunately.

 

So, I fianlly got around to changing the crank sensor. MY truck now runs again, and so far, what little I have had a chance to so far- it runs a little smoother than before it went down. The problem is that this morning, I started it, backed out of the driveway, and the check engine light came on again. With this, the tach also started going from normal readings to 0 and back. Since this is what it did moments before it dies 3 weeks ago, I am a little gun shy. I oulled the codes up on it- it said something about the crank sensor again, and a companion module? I have no idea what that means. Can someone shed some light onto why the truck is doing this?