Long Cranking Time

[Rotax3006]

Hi guys,

I'm having a hard starting issue with my 99 24v manual.  I noticed today that when i first started it it cranked for a few extra revolutions, maybe 5 seconds.  I thought the fuel had probably leaked off since its been sitting for about a week.  Went to the dentist left it set for about an hour, same issue.  Had the same issue at work after setting for 4 hours.  Tonight when I got home I immediately tried restarting the truck.  It did the same thing, cranked for about 5-8 seconds then started. Here are my thoughts: 

1). It seems to be cranking slower than normal.  This leads me to believe that it could be bad batteries/starter not spinning the engine fast enough.  Is that possible?

2).  Could I have a fuel/air leak that bad that wouldn't leak fuel.  It would have to be pretty bad to drain off that fast. 

3). Possible sensor needs replacing?

 

Notes:  Truck has new VP.  Replaced at Christmas 2 years ago. Maybe 5000 miles. Injectors are almost new as well replaced june last year. Lift pump is stock but has 13-14 PSI when you bump the key.  Truck is stock.  No CEL on.

 

Thanks in advance for your responses. 

[IBMobile]

I'd check what's behind door #1 first. 

Load test the batteries, voltage drop on the cables,  and a starter amp draw test.

  

[dripley]

I would second the above.

[Bullet]

I second @dripley's second and I third @IBMobile's first. 

[Rotax3006]

Well i did find that one of the batteries was bad so i replaced them.  That did help with the startup in the morning.  Still doesn't want to start when its warmed up.  It will start but has a pretty long cranking time 5-8 seconds probably.  Everything i have read is pointing to the VP being bad.  Its hard to believe since it has less than 5000 miles on it.  It was an industrial injection reman.  I see some posts about unplugging the LP during cranking.  I haven't tried that yet. Truck seems to run fine once it starts.  No miss or noticeable smoke.  I originally thought i might have a fuel leak letting air in.  I shut it off at work today and immediately tried starting it, same story cranked for 10 sec.  I dont believe that a air leak would cause it to bleed off that quickly without leaking while it was running.  Anybody have any other ideas? 

 

[Bullet]

One cause of a hard hot start is the electronic box (forgot what it's called) on the VP...specifically an overheat of the pump and a heat soak of the electronic box on top.  Caused by low fuel pressure...not enough extra fuel to cool the pump properly and the heat soaks the box on top.  Or bad solder in the box from too many heat soaks and/or poor reman. 

 

On the industrial injection reman pump you bought...did it come with new or reman electronics?  The warranty is longer on pumps with new electronics and for good reason.  Also what's your fuel pressure...should be 16-18lbs but definitely no lower than 14 and no higher than 20 to avoid potential hard hot start.

 

I've never had to do it but they say you can pour water on a hot VP and then try to start it to test if the box is the problem.  If it starts quickly after being doused then bingo...heat soak problem.

[Rotax3006]

I did some more testing last night.  Here is what i tried.

 

1.  Truck set for 8 hours at work and still started hard when I left.

2. The truck drops to 10.7 volts while cranking, That seems ok.  Im going to pull the starter and have it checked next.  Truck seems to be cranking slow still although my scanner states           its cranking at 300 RPM.

3. Swapped the horn relay and the fuel relay.  No change

4. Unplugged the lift pump. No change

5. Poured water on pump.  This seemed to help slightly at first, however after a couple hours I went to a meeting about a mile from my house.  It started hard when i left for meeting and        after 2 hours stetting in the shade.  VP felt cool to the touch both times. 

 

The thing that leads me away from the VP is that this started doing it almost instantly.  It was fine last week then almost overnight it happened.  It doesnt have any codes and runs really well once it starts.  Im at a loss on this one.  Thinking that maybe I have a cam/crank sensor going bad?  Possibly a bad PCM/ECM?  As far as I can tell industrial injection only uses new electronics, the pump had a one year warranty.  I have always had a fuel pressure gauge on this truck, I am running the stock lift pump. Pressure on the gauge has always read about 15 at idle dropping to 13-14 area while driving.  Might dip to 10-11 on really hot rod driving.  The last VP went 256000 miles with the same setup so i feel confident that its getting enough fuel. 

[dripley]

My truck was experiencing the same thing about September of last year. Hard starts with everything seemingly fine. Thought was an air leak in the fuel lines except it would do it right after shut down on occasion. Finally in November the VP died with a 216 code. It popped up up about 2 days before it failed. What you describe is almost identical to what mine did. But I dont want condem your VP since it is so new. If its failing like mine it is not the computer but mechanical. Mine also had 257k miles on it.

 

I bought my new one from DAP. One year warranty with new a new computer. IIRC he does have rebuilts with old ones but they are labeled as such and a bit cheaper. His are Industrial Injection also. 

[Rotax3006]

5 hours ago, dripley said:

My truck was experiencing the same thing about September of last year. Hard starts with everything seemingly fine. Thought was an air leak in the fuel lines except it would do it right after shut down on occasion. Finally in November the VP died with a 216 code. It popped up up about 2 days before it failed. What you describe is almost identical to what mine did. But I dont want condem your VP since it is so new. If its failing like mine it is not the computer but mechanical. Mine also had 257k miles on it.

 

I bought my new one from DAP. One year warranty with new a new computer. IIRC he does have rebuilts with old ones but they are labeled as such and a bit cheaper. His are Industrial Injection also. 

I know you are probably right, I just hate to have to pull the trigger on another pump especially with how little this one has been used. Probably going to go the DAP route this time.  I got injectors form them a while back and liked the service. Although Orilleys is offering a pump with a lifetime warranty......they dont know us 2nd gen guys very well !!!. Would a hotwire test would eliminate the sensors, ecm. ect? 

[Bullet]

If you're tired of buying $1000 VP's my best advice would be to spend $500 on a mechanical lift pump and your VP buying days will be over.  The stock lift pump does not provide enough pressure to cool the VP properly...even if it is working.  So it's just a matter of time before it happens again...kinda like what you just experienced.

 

My original VP is still going at 19 years old and 208k miles and has been putting out way more fuel and power than what was intended by Cummins.  Maybe I'm just lucky but I don't think so.  It only had the stock lift pump for a very short time...then went through 2 FASS failures before I finally wised up and went mechanical.  I don't know how many years/miles a VP will last yet when always properly fed...but apparently it's gonna be a really long time. 

[dripley]

The hot wire test is for eliminating the pump as the problem due to electronics. It takes all control away from the apps and the ECM. If it cranks and idles the pump is fine. This my understanding any way. I am not sure there is a test for a mechanical failure other than signs it may be failing.

My last pump lasted me 257k miles. This was on an AD elctric pump with good fuel pressure its entire life. It did suffer thru 2 pump failures and not sure far I drove it after the faileures but it did 25k to 30k miles more after the last one failed. 

@Bullet is doing well with his original. Mine let go at 75k back when the fuel was alot different than todays variety.

I tested my pressure at 100k miles while adding a Banks system to mine. At that time I idled at 10 psi and that was still at Bosh's minimum for fuel pressure. Bosch's requirements are lower than what a lot us run. This was on the oe lift pump. It lasted alot longer than the OE VP.

@Rotax3006 I have to assume your out warranty due to age and not miles. Also I cant condem your VP but it is acting like mine did before failing. 2 more things, get a proper lift pump. If plan to remain stock you can go less than a new full blown system. And 2 check into that life time warranty pump real good. See if they tell you anything about it, like the rebuilder, new or used computer. If they cant, runaway. Even though it has a lifetime warranty they are no fun to replace at inopportune times either.

[Rotax3006]

Thanks again guys.  I know I need a better lift pump, will probably get one sooner than later Covid 19 and kids are hard on the truck budget. If this vp failed I believe it had to be a faulty pump rebuild.  I know that fuel pressure was never under 12 psi for any extended period. Even with low pressure 5000 miles is horrible. Had it made 50000 I wouldn’t be too upset. My intention with the Hotwire test was to eliminate the electronic failure. That would narrow it down to mechanical issue with the pump. I don’t know if that eliminates the pump electronics though. I guess it doesn’t matter since the electronic failure requires a new pump too. 

[Rotax3006]

Just got the long cranking all figured out. Turned out to be a combination of a bad battery and a bad starter.  It fires right up now.  Took the starter off and took it in to have checked.  It passed all the load tests but sounded like death doing it.  Replaced it and sounds night and day different cranking.  Now off to address that lift pump before im back here asking the same questions.  

[Evan]

Was it the factory starter. 

If so I'd give you 30bucks for it.

[Rotax3006]

10 hours ago, Evan said:

Was it the factory starter. 

If so I'd give you 30bucks for it.

No it was a Napa reman from about 15 years ago. It actually lasted longer than the factory starter. Core charge was $40 anyway. 

[Tractorman]

On ‎6‎/‎30‎/‎2020 at 11:03 AM, Rotax3006 said:

Just got the long cranking all figured out. Turned out to be a combination of a bad battery and a bad starter.

 

So, if I am understanding correctly, the VP44 is running fine?  Engine always starts quickly and performs like it should in all driving conditions?  Just wanting to clarify that the solution to your problem was just new batteries and a new starter.

 

- John

[Rotax3006]

Yes the truck seem to be performing correctly now. It always ran fine once it started just cranked longer than normal.  It starts cold or hot now. Had trouble when it was hot before. Fires right off now. Not a daily driver but I drove it for three days this week to make sure. 
 

Bill 

[Tractorman]

Glad to hear that the VP44 is fine.  If you don't already know, there is an IOD fuse (ignition off draw) in the fuse panel that's visible when you open the driver's door.  You can pull outward on the fuse (don't remove it) and it will disable the hood light, courtesy lights, glove box light, and parasitic draws from required computer memory for things like radio, key FOB system, central timer, etc.  It would be a shame for the new batteries to have a short life because of being drained from not driving the truck.

 

- John

 

[Rotax3006]

Thanks for the tip. Appreciate all the advice.

[dripley]

Same here. It sucks when things aint right.