Engine/Transmission (1994 - 1998) No start after fuel filter change! Help!!

[PorterS]

Guys, after doing a search I still need some help. Seems as if I remember a member having this same problem some time back but can't find the post. I've been having a somewhat hard start issue with my truck usually after it sits for some time. I assume I may need to look into the lines, but I don't think this is my problem now... . Today I changed the oil and installed a new fuel filter to see if this cured my occasional hard/rough start issue. I've owned three of these 12 valves so I'm no noob, but I'm no expert either... Kill the KDP on all three and Bombed two of them. The current truck is completely stock... . Normally, after a filter change it takes a few tries to get the truck to run, sometimes with a little press on the accelerator pedal. This truck will not start after several attempts to start it. I have opened the drain and there is a good stream of fuel coming out of it... The shutdown solenoid appears to be working properly. I cracked open the supply line at the injection pump and fuel came out but does not flow out while starting the truck... . So, I'm not getting fuel from the filter to the pump. What gives here??? Anyone point me in the right direction?? Thx TDR

 

[EKlem]

Have you pulled the filter off and made sure that there isn't a piece of plastic or something covering part of it? Also did you fill the filter before reinstalling? Also, are you sure that fuel is not gushing out somewhere like a broken line or a bad filter cartridge?



I ran into a similar no start issue with my truck when I replaced my fuel lines. It turned out that I had an air leak that had been in the fuel heater and that the lift pump was sucking a lot of air. Every time I stopped pumping it, the air leak let the entire system bleed back again and I wasn't making any progress. It was amazing what that little airleak did to my attemps to bleed the system.



I would suggest trying to pressurize your fuel tank and forcing fuel up to the engine that way and seeing whether you can get it to start. A shop rag around the end of an air hose with a few pounds of pressure in the fill works great.

 

[wcjp]

On my 96' it was the soft line from the fuel preheater-lift pump. Replaced it along with the supply/return lines with Marine grade diesel line.

 

[Joe G.]

PorterS,



What year? '95 thru '96 have a spin on filter. '97 & '98 have a cartridge. You may have an air leak in a lot of places. Email me at -- email address removed -- for my write up on the fuel supply system, how it works and how to fix it.



Also it is not a good idea to prefill the filter because the inside of it is the clean side so you will be sending unfiltered fuel to the injection pump. Not good.

 

[PorterS]

It is a 97 Joe... I find it odd that this came about after a filter swap. I'm going to drop the filter again tomorrow and check it out. I have never filled the canister with fuel after a filter swap... . If it is an air leak, would changing the filter manifest the problem? The canister is full of fuel, but I have no fuel at the banjo fitting on the side of the pump... So since it's pulling fuel from the tank, can I rule out a problem at the tank? I have never seen any fuel under the truck indicating a leaky line... . Only thing I did different on this filter swap was I replaced all the orings. I normally do not replace the smallest oring unless it's damaged. Thx for the replies

 

[Joe G.]

Sometimes when you have a small leak it will get enough fuel in spite of the leak to run ok. But when you change filters the leak is just enough to kill it. I suspect the fuel heater or the gasket in the fitting on top of the fuel heater. Remember, you can't see an air leak. The write up is on the way.

 

[PorterS]

Hey thx Joe... I am trying to determine where that prefilter is in relation to the inj pump and filter canister???? I don't think I've ever seen it. I have suspected an air leak for sometime and after reading your article I probably shouldn't have replaced the filter till I found the leak. Thx again

 

[PorterS]

BTW my truck makes no black smoke whatsoever even under a hard load... I wonder if the air leak is why... It does however get killer fuel mileage : ) If an air leak is the culprit, should I expect the truck to have more power once fixed?

 

[Joe G.]

If you can make no smoke regardless of what you are doing your AFC is the most probable culpret. If your truck is a CA model with an EGR the AFC fitting is probably plugged with soot. You need to fill in your signature with year, 2500 or 3500, trans type, 4X4 or 4X2, cab type, and any mods so we can answer questions better.

 

[PorterS]

The truck is not a CA model... . Found the prefilter assembly... Never knew it was there to be honest. Kinda difficult to see past the shutoff solenoid and the fuel filter. This morning I pushed the primer button a few times and it fired up. So it's losing it's prime... Just have to figure out where. Joe in your opinion is it best to try to R&R the prefilter/lift pump with it off the truck? Kinda of a bugger to get to down there and don't really want to remove the starter to get at it from underneath. . Thx

 

[PorterS]

Sorry bout the no sig... It never occurred to me it could help diagnose a problem. Always saw the sig as more of a spot to brag about what I had... . Fixed now.

 

[PorterS]

I just removed the fuel heater... We'll see if that fixes the problem. The truck did fire up right afterwards and 15 mins later fired right up again. I did notice the rubber cover over the primer button is cracked and about to fall off... Joe, is this something I should be concerned about?

 

[Joe G.]

The O-ring for the push button is the thing to worry about. It will eventually leak because the push button mechanism is plastic. Even then, it won't cause much of a problem. Just a fuel drip. The cover just keeps dirt out. As long as it's not leaking it's no big hurry to fix. However, you should fix it when you can.



The aggravating fuel heater caused me a lot of work to find out what was wrong when it failed on mine. I'm kind of stubborn about buying parts before I know what is actually broke. In my case, I almost gave up and bought a lift pump before I finally discovered the fuel heater leak with air and a bucket of water. The poor excuse for a gasket in the fitting on top of the fuel heater is another sneaky one. In fact, just replacing the lift pump may fix that one accidently.

 

[PorterS]

It appears to be fixed Joe... Fired right up this morning after sitting all night... Your stubborness saved me some cash!! thx again

 

[dpuckett]

On the lack of smoke, if the truck wont smoke, it sounds like the AFC is doing its job. Killer MPGs and decent power are good indications of proper tuning. If i get more than a puff of smoke off the line, I start looking into stuff.



ALso, on bleeding, while it isnt bad to bleed the lines to the pump, the real bleeding needs to be done at the injectors. Push the air to the end of the line so to speak.

Daniel

 

[Joe G.]

ALso, on bleeding, while it isnt bad to bleed the lines to the pump, the real bleeding needs to be done at the injectors. Push the air to the end of the line so to speak.

Daniel

A P7100 equipped engine will start even there is no fuel in the injection lines. I've done it just to see if it would since the owner's manual for my '95 says no bleeding is necessary if you run out of fuel. I removed my injection lines to clean all the chipped paint off. When I was done I cleaned the lines out will brake cleaner and plenty of air so there was absolutely no fuel or dirt in the lines. I put them back on and did not bleed them. It took two cycles of cranking for 30 seconds and cooling for a couple of minutes to get it to start. It ran kind of rough for a few seconds before it smoothed out. Bleeding may be necessary for other pumps.

 

[SKnapp]

I've put on 69,000 of the 145,000 miles on my truck and never replaced the fuel filter. I recently did. i primed and primed and cranked. nothing so i had a friend pump while i cranked and it fired right up no problems since. man was that filter NASTY!