Truck starts and dies

[chevy4x4grl]

So I changed the fuel filter element and put new fuel in it. The truck starts and dies. The filter is racor parker after market unit. I know I'm supposed to prime the fuel system but Im not sure how to do it. I'd appreciate your help. Thanks

[moondoggie]

Good Day!

You probably have the rectangular fuel filter which is mounted on the firewall. The only thing I found that works well is to have a small (1 gallon?) fuel can filled with diesel fuel. You then fill the filter full, & spill some when you tip it up to put it on the filter holder. (It's my personal opinion that this is one of the ways the diesel fuel gets in your blood - my blood is 45 cetane. :eek: )

I don't think these trucks have a manual priming fuel pump, like virtually all farm tractors, & some other diesel pickups, have. Sooooo, you eliminate all the air you can (above), & start & run the truck until it all gets purged.

On the newer trucks (I know my daughter's 89 & my 95's have this), the fuel lift pump is electric & mounted on the frame rail. On all of these there are ways to power the lift pump without running the engine, allowing almost complete fuel priming before attempting starting the engine. I think your fuel lift pump looks just like one on a gas engine - mechanically driven, down near the bottom-front of the engine. The electric lift pumps are a blessing & a curse: easier to prime, more frequent failure (IMHO).

What's ugly about this is, if not done carefully, you can ruin a starter trying to purge the fuel lines.

[john8662]

I'm proud that you did the fuel filter change out yourself!

Could you possibly give us a good shot of the Racor fuel filter housing topside, maybe it has a air drain vent for purging the air.

At least you can get it started.

You may try and get it started again, I'd suggest a warm day too. The good thing about the Stanadyne Fuel system (injection system that is) is that it is self-priming, so if you've got some air in the system, it will work itself out. Make sure that the element is good and tight on the housing (I'm sure you already have) to insure that you're not introducing more air into the system.

Wish I was in Cali, I'd help ya out... ;)

[twaddle]

Sounds like you will have to loosen the injection pipe connections at the injectors, turn the engine over using the starter. Don't turn it over for much more than 40 to 50 seconds at a time and allow the starter motor time to cool down. When you eventually get spurts of fuel at most of the injectors tighten the injector pipes and it should fire up.
Be patient as it can take several attemps at bleeding the air out of the system and don't let the starter get too hot.

Good luck,

Jim Twaddle
Biggar, Scotland

[chevy4x4grl]

Thanks for the replies.Heres some pics of the filter. It says "in" on the top whatever that means. http://pg.photos.yahoo.com/ph/princessleia831/album?.dir=/ee9a

[DmaxMaverick]

The "IN" just means inlet.

My sugestion:

If you have a battery charger, be sure to have the batteries full up. Slow cranking will shorten the lives of the starter and batteries.

Unplug the Fuel Shutoff Solenoid wire at the top of the injection pump (pink wire). If you are unsure which wire to unplug, just makes sure all wire connections at the injection pump are disconnected (make a note as to which one went where). This will prevent the I/P from drawing fuel.

Open the air bleed valve at the top of the fuel filter ass'y. Looks like that round object with the cogs on it, in your pic.

Crank the engine for 30 seconds, and give the starter at least 2 minutes cooling time. Repeat as necessary until a clear stream of fuel escapes from the bleed valve. Normally, one 30 second (or less) cycle should be enough. The performance of your lift pump and cranking speed will determine the length of time it takes.

Close the bleed valve and reconnect the shut off solenoid.

Start as normal. It may take a longer cranking time at first, and it may run a little rough, but it will clear within a minute or two. Don't worry about any smoke, it will clear as well. If you are inside a garage, be sure to open all the doors, and don't worry about mosquitos for a while.

[john8662]

Thanks for the photo.

From the looks of the image, the air drain valve is located on the top of the filter holder. It's the white knob/wheel thats on the top.

So, what you'll do:

Get a friend to help crank over the engine.

Then pop the hood and disconnect the red wire on the injection pump. The injection pump will be in the center of the engine, under the front of the air cleaner housing. So, stand in front of the truck, and located the large round air cleaner housing, then look underneath the housing on the front side and you'll see the injection pump. It may or may not be hiding underneath the cruise control servo (if your truck has cruise). On the pump you will find three main electrical connections.

Two of the connections will be a single green wire, one will connect to the top of the pump, while the other will connect to a round cylinder known as the fast idle solenoid.

And finally, the large red wire that connects to the TOP of the pump, just unplug it and make sure it doesn't come close to contacting anything metallic. You're doing this to keep the fuel from being distributed to the injectors, and keeping the engine from starting at all.

So (long winded explanation, sorry) after the red wire is disconnected from the injection pump you can proceed to open the valve on the top of your filter holder. Just unscrew the knob until loose, you won't have to remove the knob, just open it, probably only turn one revolution, or if it stops before that.

Then, have your assistant crank over the engine after the glow plug light goes out. What you'll be watching for is fuel to start coming out of the valve or nearby. After you get fuel squirting out of the filter holder, then you've got the air out of the cartridge.

Then you can proceed to re-connecting the large red wire (fuel shutoff solenoid) back on the injection pump, and then you can start the engine.

If you have difficulty with starting it and keeping it running then post back, it could be "air locked" and have to purge the air out of the injection system as mentioned here by another poster..

on edit, DmaxMav did a good job of explaning as well...

have fun.

[DmaxMaverick]

Thanks, John. Looks like we were on the same page.

Just a note about Stanadyne fuel injection systems, and GM:
Way back when, GM made demands of Stanadyne in regards to the design of the fuel injection system. One main requirement was user friendliness. Meaning, the system must be easy to maintain, and service by the consumer (you and me). There is much mention on this and other forums about loosening the injector lines to cure an "air lock". The system is designed so this is not necessary. While it will expedite the bleeding process, it does require a little more skill than is generally had by most consumers. If you feel handy enough to mess with injector lines, by all means, do so. The only gain will be a shorter clearing-up time after the initial start. I only do it if time and conditions allow. All things considered, it will take longer to get going again at 100%, than not doing it. The Stanadyne fuel injection system is very thorough at purging air once the engine is running, provided you don't have an ongoing air issue.

[chevy4x4grl]

Well this truck runs like new. I have never had any starting problems (or any mechanical problems for that matter :D ) so I know I dont have an ongoing air problem. So I should just open that vavle on the top until fuel squirts out huh? I dont need to watch for air bubbles in a tube like when you bleed brakes? Im sure you can tell I'm new to diesels lol.

[DmaxMaverick]

Don't worry about watching for bubbles. Once you get a stream of fuel, the rest of the air will work itself out easily. The key is to get the engine running so the pumps can do their jobs. Unplugging the shutoff solenoid expedites the bleeding process, by not allowing the injector pump to suck in too much air.

[chevy4x4grl]

Thanks everyone! I'll give it a try tomorrow. I want to have it up and running so I can take it to my diesel tech class (I hate driving my moms Rav 4 lol)

[Trevor Besson]

HI I have the same filter set up on my truck. The white knob in the center is the priming pump the nut on the inboard (driver side) is the vent. crack the vent, unscrew the primer wheel and pump it until there is clear stream of fuel from the vent close the nut and your done. hope this helps Trevor

[ZZ]

I prime my truck after a filter change by jumpering the leads on the pump fuse under the cover of the power center on the passenger side of the firewall. I open the valve on the filter block and run the pump till fuel comes out. Then I put everything back and then start & drive.

[DmaxMaverick]

ZZ

Mechanical fuel lift pump. It only operates with engine turning. You can "jump" any wires you want, it won't make the pump "pump".

[chevy4x4grl]

Originally posted by TB1:
HI I have the same filter set up on my truck. The white knob in the center is the priming pump the nut on the inboard (driver side) is the vent. crack the vent, unscrew the primer wheel and pump it until there is clear stream of fuel from the vent close the nut and your done. hope this helps Trevor I used this method and got it to start and keep running smile.gif Now however its making a kind of hissing noise when I take my foot off the gas. However, I doubt thats related to my previous problem.

[wthif]

I'm glad you got your truck running again. I was going to offer to come down this weekend and help you if the truck wasn't running right. I can't help you with the hissing sound with out hearing it, but I''ll bet you'll figure it out. I'm fairly busy during the semester because I'm trying to finish up one degree and start another, but if you ever get stumped and want a hand just post and as evident everyone will do there best. Also like I said I would be wiling to try and come down and help if needed. Monterey is about 40 to 45 minutes for me.

[ZZ]

Originally posted by DmaxMaverick:
ZZ

Mechanical fuel lift pump. It only operates with engine turning. You can "jump" any wires you want, it won't make the pump "pump". I'm sorry. I should've read closer. I had an '85 Chev with a mechanical pump. I changed it over to an electrical pump and wired it to the pink wire going into the IP pump solenoid. Filter changes were always easy after that.

[doncannon]

ZZ,
thank you for the idea. my 87 has a elect pump (someone before me converted) and I think that is a better idea for power for my elec pump!
thank you,
Don