Mack Superliner (Hard 1St Start) When It Sits For Awhile

[LAZRGUIRA]

Hello All..

I seem to be having and engine “hard start problem”. It’s a 1987 Mack superliner with 350 in it. (E6 or E7) can’t remember.

The engine is completely rebuilt with less than 100 miles on it (rebuilt heads,turbo and injectors too). The only thing that I did not rebuild is the pump.

So anyway here’s the problem. If I let the truck sit for a few days it takes a lot of cranking to get it started. Usually kills my battery’s and turns into a long process after that since I have to charge them back up and keep cranking.

But when It starts she runs like a champ. And I can turn it on and off all day and it will fire up immediately. In the summer if I would run the truck every day it would start pretty quick too.

The problem seem s to be when I let it sit for a long time. I personally think that somehow the fuel must be draining back into the tank. And that’s why I have to crank it so much so I can fill the lines again. Is this possible?

Also on the injector pump, a couple of the fuel lines that go in to the pump appear to be leaking.(not bad but its leaking. I can see the stain) I might have to replace them because I believe they are already threaded all the way in. could this be it?

Could it be that the fuel filters are plugged? I never changed those either. (long story). I bought this truck as a project and never even got to use it. Since the economy hit me pretty hard.

It’s been sitting for 3 years now and I’m ready to finish her up now and put it to work but first I have to fix that problem before I go ahead and put new battery’s in it.

Do you think my pump need to be rebuilt? When its running it seem s to running great. Thanks in advance and sorry for the long story.

[fjh]

Hello All..

I seem to be having and engine "hard start problem". It's a 1987 Mack superliner with 350 in it. (E6 or E7) can't remember.

The engine is completely rebuilt with less than 100 miles on it (rebuilt heads,turbo and injectors too). The only thing that I did not rebuild is the pump.

So anyway here's the problem. If I let the truck sit for a few days it takes a lot of cranking to get it started. Usually kills my battery's and turns into a long process after that since I have to charge them back up and keep cranking.

But when It starts she runs like a champ. And I can turn it on and off all day and it will fire up immediately. In the summer if I would run the truck every day it would start pretty quick too.

The problem seem s to be when I let it sit for a long time. I personally think that somehow the fuel must be draining back into the tank. And that's why I have to crank it so much so I can fill the lines again. Is this possible?

Also on the injector pump, a couple of the fuel lines that go in to the pump appear to be leaking.(not bad but its leaking. I can see the stain) I might have to replace them because I believe they are already threaded all the way in. could this be it?

Could it be that the fuel filters are plugged? I never changed those either. (long story). I bought this truck as a project and never even got to use it. Since the economy hit me pretty hard.

It's been sitting for 3 years now and I'm ready to finish her up now and put it to work but first I have to fix that problem before I go ahead and put new battery's in it.

Do you think my pump need to be rebuilt? When its running it seem s to running great. Thanks in advance and sorry for the long story.

Go after them damp spots first see if that repairs the problem Check the plastic line between the pump and the head and the jumper between the heads!

Also the valve that the plastic line goes to, take the end off of that and check to make sure the spring is not broken.

[LAZRGUIRA]

Go after them damp spots first see if that repairs the problem Check the plastic line between the pump and the head and the jumper between the heads!

Also the valve that the plastic line goes to, take the end off of that and check to make sure the spring is not broken.

Thank you very much. I will definetly give it a shot. sucks becuase i cant's get to it now becuase the sorage yard is full of snow.I'll keep you posted.

you would happen to have some sort of diagram or pictures that show the parts you mentioned would ya?

[oldmacktrucks]

Hmmmmmmm....I would have to say more than likely sounds like a bad supply pump, I had the same problem on a 94 RD tractor I had. I would start with the basics, check the fuel lines, replace the filters. But more than likely I would put money on it being the pump

[oldmacktrucks]

Hmmmmmmm....I would have to say more than likely sounds like a bad supply pump, I had the same problem on a 94 RD tractor I had. I would start with the basics, check the fuel lines, replace the filters. But more than likely I would put money on it being the pump

When I say pump I dont mean the injector pump...I'm talking about the supply pump that mounts to the injector pump, should have 2 fuel lines going to it and possibly a primer.

[LAZRGUIRA]

Hmmmmmmm....I would have to say more than likely sounds like a bad supply pump, I had the same problem on a 94 RD tractor I had. I would start with the basics, check the fuel lines, replace the filters. But more than likely I would put money on it being the pump

Sombody told me that in the back of the pump there is some sort of check spring or somthing.If i remember correctly you take cap off and pull it out. Not shure it's been a while.

but anyways they said that might be the problem aswell. I'm gonna go gun-ho pretty soon checking everything. The trucks gotta be ready by the 2nd week in march.

How much does it cost to rebuild the pump anyways? Thanks

[oldmacktrucks]

From the sound of it, its NOT the injector pump, but to go thru the pump (if you wanted it done) around $1000.00 to $1500.00 I just had one done. A new supply pump should only be a couple of hundred. If the truck runs good, but is losing prime after sitting I would put my money on the supply pump. There is a check valve on the return line that sometimes goes bad, but I would start with the pump. I pulled my hair out for 2 weeks trying to fiqure mine out, everyone told me its the lines, its this its that...I went with my gut instinct, replaced the supply pump and bingo she fired right up and never lost prime again.

[Rob]

Sombody told me that in the back of the pump there is some sort of check spring or somthing.If i remember correctly you take cap off and pull it out. Not shure it's been a while.

but anyways they said that might be the problem aswell. I'm gonna go gun-ho pretty soon checking everything. The trucks gotta be ready by the 2nd week in march.

How much does it cost to rebuild the pump anyways? Thanks

A rebuild kit for the transfer, (or lift) pump mounted to the side of the injection pump is a great idea to "freshen up". Think the last one I did was about $30.00 for parts through PDI. These are the same quality as you would get through Mack but much less expensive. Never a good idea to have seepage in the fuel lines as it always leads to faults. Liquid fuel cannot be compressed where air can and this is why it takes a while to start if the fuel is draining back even if not completly dry. You must displace the air with fuel before the injectors start to crack, or pop open.

There is a check valve in the transfer pump and it can gum, or the spring can break/fatigue. Both will cause drainback.

Rob

[oldmacktrucks]

A rebuild kit for the transfer, (or lift) pump mounted to the side of the injection pump is a great idea to "freshen up". Think the last one I did was about $30.00 for parts through PDI. These are the same quality as you would get through Mack but much less expensive. Never a good idea to have seepage in the fuel lines as it always leads to faults. Liquid fuel cannot be compressed where air can and this is why it takes a while to start if the fuel is draining back even if not completly dry. You must displace the air with fuel before the injectors start to crack, or pop open.

There is a check valve in the transfer pump and it can gum, or the spring can break/fatigue. Both will cause drainback.

Rob

Lift / Transfer is the right term...and was on the tip of my tounge. Supply pump was close though I paid around $200.00 for mine plus core charge

[LAZRGUIRA]

Lift / Transfer is the right term...and was on the tip of my tounge. Supply pump was close though I paid around $200.00 for mine plus core charge

Thank you guys alot.. I really appreaciate all this. I wish i could go do it rite now! I'm all fired up. But unforchantly i can't get the truck rite now But i will..

Now i have a few places to start.

Edited February 8, 2011 by LAZR GUIRA

[oldmacktrucks]

I'm curious, and have my money on the lift pump...be sure and keep us updated!

[Rob]

Thank you guys alot.. I really appreaciate all this. I wish i could go do it rite now! I'm all fired up. But unforchantly i can't get the truck rite now But i will..

Now i have a few places to start.

Should you decide to rebuild the transfer pump; get a small piece of "crocus cloth" and lightly "massage" the sealing surface the check valve disc sets against. If the fuel has had water in it these can corrode but the truck would have to have been setting for a spell as this does not happen overnight. The only time I've seen a transfer pump need to be replaced with a reman unit is from deterioration of the pump cavity material from a foreign substance, (usually water). I've seen some rebuild kits also not have the primer piston in the kit. I like to replace that also for safe measure if nothing else.

As a final note: take the transfer pump off the engine. I've seen guys do this in the driveway but you can't get everything really clean to put it back together that way. I like to use the kitchen table and carburator cleaner; It really gets "Momma's" attention.

Rob

[oldmacktrucks]

Should you decide to rebuild the transfer pump; get a small piece of "crocus cloth" and lightly "massage" the sealing surface the check valve disc sets against. If the fuel has had water in it these can corrode but the truck would have to have been setting for a spell as this does not happen overnight. The only time I've seen a transfer pump need to be replaced with a reman unit is from deterioration of the pump cavity material from a foreign substance, (usually water). I've seen some rebuild kits also not have the primer piston in the kit. I like to replace that also for safe measure if nothing else.

As a final note: take the transfer pump off the engine. I've seen guys do this in the driveway but you can't get everything really clean to put it back together that way. I like to use the kitchen table and carburator cleaner; It really gets "Momma's" attention.

Rob

Dont forget using "momma's" good dish towel as a placemat and the bent fork and "butter knife" screwdriver...that was "borrowed" out of the china cabinet! I've been down that road and trust me it aint purty!

[vision386]

Dont forget using "momma's" good dish towel as a placemat and the bent fork and "butter knife" screwdriver...that was "borrowed" out of the china cabinet! I've been down that road and trust me it aint purty!

I once re-jetted an old Carter AFB carburator for a friend of mine on our kitchen table,used (un-known to me) a "good" dishtowel for a shop rag,Mrs. Vision was not happy! did'nt go good at all for me!................Mark

[Rob]

Dont forget using "momma's" good dish towel as a placemat and the bent fork and "butter knife" screwdriver...that was "borrowed" out of the china cabinet! I've been down that road and trust me it aint purty!

I have learnt at least one thing in my life and that is "Hide what you stole" before she gets into the room!!

Rob

[Rob]

I once re-jetted an old Carter AFB carburator for a friend of mine on our kitchen table,used (un-known to me) a "good" dishtowel for a shop rag,Mrs. Vision was not happy! did'nt go good at all for me!................Mark

Can't tell you how many times I've rebuilt a Holley, Carter, Rochester, Stromberg, Weber, Zenith, and the like on the kitchen table. The best carb cleaner in the world is a product by "Kleen-Strip" spray gun cleaner. You learn really quick to not put your hand in the shit very long, and don't submerge plastic parts in it. You will get bare and clean aluminum from the bath that rinses right off.

Then your wife or significant other will really be pissed at you cause the stench permeates any porous material in the house with a lingering effect. "Momma" just LOVES that smell and always grabs a frying pan to try to capture the essence that seems to eminate around my skull.

Rob

[oldmacktrucks]

I have learnt at least one thing in my life and that is "Hide what you stole" before she gets into the room!!

Rob

That only works until she takes out the trash and see's the "butter knife" flathead sticking out of the hefty bag...then your in deep, well you know LOL

[gearbox]

could try to pump hand primer to build the pressure before turning it over it may eliminate lift pump trouble if it still doesn't start well it maybe deliver valves leaking in pump

[other dog]

I once re-jetted an old Carter AFB carburator for a friend of mine on our kitchen table,used (un-known to me) a "good" dishtowel for a shop rag,Mrs. Vision was not happy! did'nt go good at all for me!................Mark

I know that feeling very well-I used a "good" dish towel to wipe down my cast iron stew pot after I used it and re-seasoned it with crisco one time.

[Rob]

I know that feeling very well-I used a "good" dish towel to wipe down my cast iron stew pot after I used it and re-seasoned it with crisco one time.

Just throw the towel in with the next batch. No problem.

Rob

[LAZRGUIRA]

Just throw the towel in with the next batch. No problem.

Rob

haha thanks guys.. My old lady is use to me rebuilding holley's on table... Thats where i'll be rebuilding this pump also. How can i pump it by hand? any body got pics laying around.. Don't know much about diesels but i can build one hell of-a SBC Thanks

Edited February 8, 2011 by LAZR GUIRA

[LAZRGUIRA]

A rebuild kit for the transfer, (or lift) pump mounted to the side of the injection pump is a great idea to "freshen up". Think the last one I did was about $30.00 for parts through PDI. These are the same quality as you would get through Mack but much less expensive. Never a good idea to have seepage in the fuel lines as it always leads to faults. Liquid fuel cannot be compressed where air can and this is why it takes a while to start if the fuel is draining back even if not completly dry. You must displace the air with fuel before the injectors start to crack, or pop open.

There is a check valve in the transfer pump and it can gum, or the spring can break/fatigue. Both will cause drainback.

Rob

Can someone send me the the link where i can buy this kit for about $30 ? I keep try to find "PDI" but i'm coming up short. There seems to be alot of companys that start with letters PDI. Thanks

[Rob]

Can someone send me the the link where i can buy this kit for about $30 ? I keep try to find "PDI" but i'm coming up short. There seems to be alot of companys that start with letters PDI. Thanks

PDI is a supplier to truck parts vendors. You cannot purchase from them directly to the best of my knowlege. Call these guys, http://www.sadlerpow....aspx?tabid=267 ask for Kevin. He's always been right with me on Mack stuff. Tell him I said "hi" and I'll see him the first part of next week.

Looks like the PAI part number you need for a rebuild kit is: EKT-2221, and the Mack kit number is: MAK 79-KT948.

There are many more on here much smarter than I when looking up part and hopefully they can chip in if Kevin can't help.

Until "Other Dog" come round here and converted me to one of the site smart asses, I used to be helpful at times. We ain't heard much from him in a couple days. Hope he didn't eat any of that stagnant "pouch meat" when visiting Marsupial, IL last week.

Rob

[LAZRGUIRA]

PDI is a supplier to truck parts vendors. You cannot purchase from them directly to the best of my knowlege. Call these guys, http://www.sadlerpow....aspx?tabid=267 ask for Kevin. He's always been right with me on Mack stuff. Tell him I said "hi" and I'll see him the first part of next week.

Looks like the PAI part number you need for a rebuild kit is: EKT-2221, and the Mack kit number is: MAK 79-KT948.

There are many more on here much smarter than I when looking up part and hopefully they can chip in if Kevin can't help.

Until "Other Dog" come round here and converted me to one of the site smart asses, I used to be helpful at times. We ain't heard much from him in a couple days. Hope he didn't eat any of that stagnant "pouch meat" when visiting Marsupial, IL last week.

Rob

Thank you very much...will do. This weekend i'm gonna see if they plowed the storage so i can get to the truck it's full of snow.