Archived Starting Problem 98 24v

[Johnny5]

My buddy's truck is down after recent trip. It is a 98 24v.



A little history on what lead to this. Halfway thru the trip he stopped to fuel up and could not restart. After purging a lot of fuel it was able to run and get home only to have it die right in his driveway when he went to back up altho he noted he did not have to stop or idle at any time from where it originally stalled and where it sits now.



So today we changed the LP and fuel filter and we got it running after quite a bit to purge the air (I got a nice fuel bath while backing out the NPT plug at the top of the FF). Truck was idling for 15min and we thought it was solved. I left and called him back and he said when he put it in drive it was sputtering, placed back in park and it cleared then back in drive and very soon after it stalled. Now it will not start. There is fuel pressure and I'm almost sure it would start if I pull the NPT plug on the in side of the FF because that was exactly what was done both times when it started backup after both stalls,at the fueling station and after the LP/FF change.



So as it stands now there is no Check Engle Light and I'm leaning towards a bad VP44 since it was running today. Will a VP44 cause a hard start/stall w/o turning on the CEL? How can we check the VP44, by cracking a injection line or something else? I thought it could be a trans isuse but that does not explain the hard to start/no start condition after the stall. Any help will be appreciated...

 

[p-Bar]

From my past readings I would say a bad VP44 . It can be tested by plugging into the VP by the right mechanic. They seem not to run after getting warm. Others will chime in.

 

[Missouri Mule]

When he purged the first time was there air in the system?



When you changed the LP and fuel filter I think you should of cracked a few injectors to make sure the air was out. I have read the fuel system can purge itself of some air.



I don't know if the 98s could do the key on-off... to get codes you mite have use a scanner.



Bad fuel? Water in fuel?

Sounds like there is air getting in somewhere especially if it starts again once you purge the system of air.

 

[JLandry]

I would agree that it sounds like a VP44 failure *if* you've ruled everything else out... like the things Missouri Mule suggested.



Regarding air in the system...



Normally when changing a lift pump you will not need to bleed air from the injector lines, but it's a good practice to purge air from the supply lines leading to the VP44 by loosening the fuel inlet fitting at the VP44 and bumping the starter (to activate the lift pump for 25 seconds). Then, if the engine will start, idle, and rev up in neutral, then you don't have a problem with air in the lines or VP44. Purging air from 2 or 3 of the injector lines is only needed to get the VP44 primed (if it's lost it's prime) enough to start the engine. Once the engine is started the VP44 will push air out of the injector lines. Now if you keep getting air in the supply lines and fuel filter cannister, then it's possible there's an air leak in the fuel line somewhere between the tank and the lift pump. That's possible but rare. Unfortunately what's more common is a VP44 failure!



To check for trouble codes you'll need a code scanner available from any auto parts store or your favorite variety store like WalMart, etc.



Good luck,



John L.

 

[Johnny5]

A day after the LP/FF change we pulled the following codes, P0216 (2x)Injection Timing Control Circuit,P0237(2x) Boost Sensor Circuit Low,P1693 Comapanion DTC in ECM/PCM. After we checked the codes we just gave it a try and it started right up and since it sat for almost a full day I would suppose that would say there is no air in the system, especially since we did nothing addtionally to purge air since the last stall. He was able to move the truck but as soon as he took his foot off the pedal it soon died. We did notice a very small leak at the washer area at the output side of the Airtex pump. I was initially a little skeptical about this type of connection since it was only a solid washer and a very low torque spec, but it did startup right away so this small leak did not seem to affect starting (at least on the 2nd time it started).



He wanted to leave the codes in the truck and I checked again after the last stall and no addtional codes were added.



As for the fuel, we are guessing it should not be a problem since he fueled up with 20+ gallons at a truck stop at which time the truck initially did not start and since he did notice a slight stumble 3hours of driving before the fill-up.



So he is going to talk to MWFI since they are close by to see if a VP44 is needed which we believe may be the case altho we are not 100% sure at this time

 

[JLandry]

P0237(2x) Boost Sensor Circuit Low

That P0237 code is a little suspicious and makes me wonder if it could be causing the VP44 to act strange.



I think I'd clear the trouble codes, start the engine, try to move the truck in gear like he did before, and see if you get that P0237 code back again before I resorted to replacing the expensive VP44. If you do get the P0237 code again, then replace the MAP sensor to see if that corrects the problem. If it doesn't, then he's only out $40 or so for the sensor and can move on to replacing the VP44.



Good luck,



John L.