Hard start..

R

redcam622

New member
Joined
Jan 21, 2010
Messages
20
This has prolly been gone over a 1000 times..but yesterday, my truck started to take over 30 seconds of steady cranking to fire..weather its cold or hot,doesn't matter...at least 30 seconds if not more..but no codes..and once it starts,it runs perfect...not the lift pump..i have 2 and its reading 20 psi at the vp44. and i can't find any leaks. I know the first thing everyone says is the pump,but is there anything else that will cause this?
 
does it crank longer if you park the nose uphill? Start good if you park the nose down hill?
 
always level..and was fine one day..bad the next...even if it's running and you turn it off,and try to re-start right away..takes at least 30 seconds.
 
was told that..but looked and doesn't seem to have any obvious probs. Where would be a good place to start?
 
what i would do is crack a line on the head and have someone crank the truck and watch for fuel, if no fuel for a little bit your either sucking air or something wrong with the pump even tho you say its good. JMO
 
Is it your original IP? The older ones had a thinner internal diaphragm that will rupture with the addition of a upgraded lift pump. Later ones had a thicker one. The way I was taught is that its the internal pressure regulator and with the new found pressure of a better LP the rubber is not used to the pressure and ruptures. Longer and longer starts turns into no starts w/o ether. A fix is to plumb a hobbs switch on the oil filter mount so the LP doesn't fire till after the engine does. The easy method to check is disconnect the LP relay and see if it fires instantly. This is the only reason I replaced my IP, eventually only ether would start it. Always ran perfect once started though.
 
nrose07 said:
Is it your original IP? The older ones had a thinner internal diaphragm that will rupture with the addition of a upgraded lift pump. Later ones had a thicker one. The way I was taught is that its the internal pressure regulator and with the new found pressure of a better LP the rubber is not used to the pressure and ruptures. Longer and longer starts turns into no starts w/o ether. A fix is to plumb a hobbs switch on the oil filter mount so the LP doesn't fire till after the engine does. The easy method to check is disconnect the LP relay and see if it fires instantly. This is the only reason I replaced my IP, eventually only ether would start it. Always ran perfect once started though.
Click to expand...

true I forgot all about this option:Cheer:
 
yup

nrose07 said:
Is it your original IP? The older ones had a thinner internal diaphragm that will rupture with the addition of a upgraded lift pump. Later ones had a thicker one. The way I was taught is that its the internal pressure regulator and with the new found pressure of a better LP the rubber is not used to the pressure and ruptures. Longer and longer starts turns into no starts w/o ether. A fix is to plumb a hobbs switch on the oil filter mount so the LP doesn't fire till after the engine does. The easy method to check is disconnect the LP relay and see if it fires instantly. This is the only reason I replaced my IP, eventually only ether would start it. Always ran perfect once started though.
Click to expand...
Exactly as you stated..i disconnected the aux. lift pump and it fired instantly..hooked it back up and it just cranked...been driving it around all day and started 20 time perfectly and ran great...am going to hook up a hoobs switch like you said to fire the pump after starting....Thanks.
 
I have this problem, but only when it's less than full or parked on a slope. I know what my problem is, just haven't fixed it yet. Check for a fuel leak somewhere, if the pressure in the fuel lines bleeds off your going to have trouble starting it.
 
The less then full or parked on a slope is a different issue, completely unrelated. That's loosing your prime, this is a internal pump failure that you can band-aid.
 
I know I have a fuel leak, I can see it. But it's been cold, nasty, and rainy. And I'm lazy in that kinda weather.
 
so if i can hijack this, my truck is pretty random fires right up sometimes and not others, will take 10-20 secs to start. the vp is a couple years old so i hope its not the diafram. i have a fass so its above 15 psi at all times (not over 18).
where do i start looking
 
I've always been told that if the pump got rebuilt in the last 8 or so years that it has the thicker diafram.
 
One of my buddy's trucks was hard-starting for a few years-went to the Dodge dealership multiple times with no resolution. Eventually it started putting fuel into the oil on short trips-nothing on longer ones. The only thing I could find wrong with it when we pulled it down was the body O-rings on the injectors. 3 of the 6 spun in their bores when screwing the bolt in to pull them out and slid out as easy as can be, the other 3 required a pry bar to pop them. We swapped the injectors at the same time-so I can't say 100% that there wasn't a cracked one although I guess I could pull them off the shelf and pop them to see. End of the problem anyway-I've never seen an injector that easy to pop out before. These were small BD X-Pulses or something like that-why only 3 of the 6 O-rings were bad boggles me though.

Jason
 
You must log in or register to reply here.
Back
Top