Engine/Transmission (1998.5 - 2002) Wondering if the check valve is bad.

[HookMeUp]

Wondering if the VP44 check valve is bad.

about 2 weeks ago I had the lift pump replaced with the in tank pump. The old pump would drop pressure and then build back up, usaully after i shut it down. With the new pump I am seeing 6. 5 psi idle, and then at times I see 3 psi at idle. I'm, wondering if the check valve on the outlet of the injector pump is bad.

 

[HookMeUp]

Pushing back to the top in hopes that somebody knows something about this.

 

[azpete]

I don't have the in tank pump but when mine started acting up the opposite of yours -normal at 14 and alot of times will be 19- I bought a new check valve. It didn't make a difference so my old one should be good. If you would like to have it just PM me on where to send it and it's yours, but I'm thinking that more than likely it's the pump.

 

[DMannon]

Probably not the check valve... those in-tank LPs are notorious for low pressure. Do a search on it here; you'll find lots of dissatisfied customers.

 

[CKibler]

I think its your lift pump. I just removed my second intank pump and replaced it with the walbro system. My pressure was doing just about what yours was on a pump that was only a week old. I don't have the problem now with the new set up.

 

[DLausche]

I too am wondering what the symptoms are when the check value is not working correct. My FP has been wacky for a long time now. New gauge on last week and the FP goes up and down from 1 to 13psi. At idle the FP is zero or 1 usually but sometimes reads 13-14. 1/3 or more throttle and it always pops up to 13 or 14. If I let off quickly it will usually drop right to 1. Let off slowly it will wander around between 5 and 14 and then eventually fall to 1 until I give it more go pedal and then it pops up again. Have measured voltage at pump while driving and it is pretty steady at 13. 7v. Voltage drops down very slightly to 13. 6v when the FP pressure goes up - assuming this is because the pump is under more load and drawing more current.



I figure pump is either cavitating and pressure goes down until more flow demand from VP or the check valve is causing the problem.



What are symptoms when the check valve is malfunctioning?



-Deon

 

[HookMeUp]

I don't have the in tank pump but when mine started acting up the opposite of yours -normal at 14 and alot of times will be 19- I bought a new check valve. It didn't make a difference so my old one should be good. If you would like to have it just PM me on where to send it and it's yours, but I'm thinking that more than likely it's the pump.

Thanks for the offer, but I don't think I will need it. I did an oil change over the weekend and pulled the check valve off, looked fine to me. Looks like it's back to the dealer for some more fighting.

 

[DLausche]

I don't have the in tank pump but when mine started acting up the opposite of yours -normal at 14 and alot of times will be 19- I bought a new check valve. It didn't make a difference so my old one should be good. If you would like to have it just PM me on where to send it and it's yours, but I'm thinking that more than likely it's the pump.

Hey azpete, do ya still have that spare check valve? My FP has been wacky for a long time now. Just put in a different LP and filter and dit is still not right. I think it makes sense to try replacing my check valve next.



-Deon

 

[azpete]

PM me with your address and I'll get the valve out to you.

 

[DLausche]

Thanks!

azpete, I need to give a sincere thanks to you for sending me the spare check valve you had. I finally had a chance to put it in today before the snow started flyin here. Work schedule has been crazy lately. Unfortunately, my wacky fuel pressure is still wacky. I am going to try and find a gearotor pump to replace the rotary vane pumps that I have been having such bad luck with.



To anyone else that does or thinks they may need to replace their check valve, I have an extra one and it is in working condition. I would like to pass on the favor given to me by azpete, so let me know if you need it and I will send it along to the next person. I could post this in pay it forward, but I think it is likely that someone who really needs it may be reading thru this thread at some point in the future.



-Deon

 

[azpete]

Hope you can get the problem figured out soon. Always seems the cheapest, easiest fix does not work. Mine still goes to the high side on the pressure at times. That is fine by me. If I have to replace again, will go with the Walbro pump and draw straw.

 

[HookMeUp]

Still having problems with pressure, took it back to the dealer. They had it all day and said it was fine, they just didn't get it into their heads that 0psi is not good! I have the pump kit from the cummins campaign that I am going to install in the stock location so that I have them both running in series. We'll see what the results of that will be. Have you checked out this tech article: http://www.glacierdieselpower.com/images/PDFs/IntankPumpExposed.pdf



After reading this it sheds a little light as to why the pressure is all over the place. Looks like a good pump with good flow and pressure, but yet again another bad implementation by DC.

 

[DLausche]

I sent the check valve on to klaybus this morning. Hopefully he can get use out of it. If not, then keep azpete's generosity alive and send it along to the next person that might need it.



-Deon