Just joined tonight so HI all.


What was the solution to the hard start when hot the Mike M. was having in this thread? https://www.dieselbombers.com/diesel...se-help-3.html

symptoms:
Starts first crank every time when it's stone cold. Wait to start light comes on then goes off if it's not cold, lift pump runs, truck starts right up..

When it's hot, no wait to start light, no ligt pump, cranks but no start.

Now, if I turn the key on but don't try to start it the wait to start light will come on after about 15-25 seconds. The lift pump comes on at the same time as well and the truck will fire right up.

I have found that if the wait to start light doesn't at least flash on and then go off the truck will not start.

Once started it runs fine.

Bombing history.

purchased the truck new in 99.
at 35k miles I installed 275 hp rv injectors and had the ECM flashed by TST (way back when)

4" exhaust was installed at some point but I forget when I did that.

100k miles later I stacked what was then called the "hot" program for the Edge fueling box on top of the flashed ecm. upgraded the turbo to one of Piers ported HX35.

At 250k miles and a few trannies and clutches later I removed the edge box after going though 2 VP44 pumps.

thanks
Mike B

 

Something tells me the VP maybe going again??

 

I dont see a fuel pressure guage in your list of mods. Do you have a fuel pressure guage?

Do you have any other symptoms?

How about white smoke?

What kind of fuel pressure are you seeing? I would throw the scanner on to check for codes. I suspect you will see the dreaded P0216 again.

 

Does anyone know where the signal for the lift to start and the wait to start light originate? I was really thinking it's some sort of relay but so far all of the relays in the fender mounted box check out. how about an ingition switch going south? It feels like something is not tellling the truck to send fuel.

to answer your questions.
I'm not having any symtoms of a failed VP44 at least nothing like before. The last time the VP failed and I had no start issues the lift pump would run and the wait to start light would flash on as it should.

no white smoke.

I don't have and fuel pressure guages installed but the lift pump when it runs is working. When I changed the fuel filter last month I tossed a guage on the housing just for grins. Start up psi and running psi were on the low side but not too bad.

Years ago I found out the lift pump died because it was so week that it couldn't even fill the filter canister after a filter change. The funny thing was that the truck ran fine but had a loping idle if you revved up the engine and let it return to idle. (this was before the lift pump was replaced). 50k miles later the VP kicked the bucket.

A failed VP was my first thought but the the symptoms just don't match my past experiance.

in the thread I linked to a Mike M. said he took his truck to the shop for repair but never came back to post the cause of the problem. That thread is now closed..

thanks for the help guy but it going to be too nice out today to fool with trucks...

Mike B.

 

Like I already said, you need to put a fuel pressure guage on it and scan for codes.

 

Allmost sounds like a lazy fuel pump relay.

 

Good call.....he could try swapping the fuel pump relay in the power distribution center and see if that helps.

 

well, Two injection pumps in 340K miles with over 300K of those miles bombed doesn't sound that bad. Just because I don't have a fuel pressure installed as a fixed gauge doesn't mean I don't check the lift pump psi with a temp guage each time I change the fuel filter. I didn't mean that just because I heard the pump running I assumed it was making pressure.

True, hard start is a classic symtom of a failing VP44 pump however the "wait to start" light not flashing on (I mean coming on and going off, not realy flashing) and the lift pump not starting with key on is something different.

If I turn the key on and sit and wait until the wait to start light comes on and goes off again the truck will start every time, hot or cold.

I've check all the relays in the PDC when I thought it may be the ASD relay.

tonight I hooked up my scanner to check for codes, nothing.

thanks

 

Mike, did you try swapping the fuel pump relay with a different one?


I have never had any issues with my wait to start light - and have yet to recall seeing it discussed on a forum.

You really should have a full time fuel pressure guage. It helps see the lift pump performance over time. And I did not catch how many miles you have so - yeah 2 VP-44's isnt that bad.

 

I dropped the truck off a the shop to have it looked at. The poor thing needs the right front wheel bearing replaced as well as some other front end parts so I decided to let my local shop make a party out of it.

I'll post the results when I get it back.

Dr.Evil, no go on the fuel pump relay.