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mhotrodscooter

04 Al-350 fuel pressure

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can anyone tell me what idle fuel pressure is supposed be? this one 60psi @idle and 82psi wot. fighting a fuel dilution problem.

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Your in the zone with what you you have! We have had this problem and it was injector! Having said that Mack E service had us put die in the fuel filter and run the engine for a minute or so the die showed up right away at the offending injector under the black light ! In your case in an MR its going to be tough cause half the truck has to come apart to get the valve cover off How ever its either this or replace all six!

Just Sayin!

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50-85PSI full rev and no load.

No need to reinvent this wheel....Click on link, may be helpful.

 

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2 minutes ago, Mack Technician said:

50-85PSI full rev and no load.

No need to reinvent this wheel....Click on link, may be helpful.

 

Good call  Teck I didn't read the tittle  Duhhh! I assumed his  15 MR!

Edited by fjh

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5 minutes ago, Mack Technician said:

50-85PSI full rev and no load.

No need to reinvent this wheel....Click on link, may be helpful.

 

i read that link yesterday. oil pan was off 300 hours ago. changed delta seal, only 500hrs or so on eup pumps, nozzle o'rings change 300hrs ago, fuel dilution went from 5.3 to 8.5 on this sample. new oil and filters installed 300hrs ago. ive checked the fuel bore plugs when the pan was off. no leaks from that area then. think the eup pumps have done took a dump? they was mack remains funny thing we have a e7 having the same issue with around 1000hrs on its eup pumps 

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52 minutes ago, fjh said:

Your in the zone with what you you have! We have had this problem and it was injector! Having said that Mack E service had us put die in the fuel filter and run the engine for a minute or so the die showed up right away at the offending injector under the black light ! In your case in an MR its going to be tough cause half the truck has to come apart to get the valve cover off How ever its either this or replace all six!

Just Sayin!

thanks for the input. ive aready learned alot from this site in a short time, 20years of automotive switching over to big rig stuff is tough, not enough info out there like on gas burners

ive got a mp7 that i did a leak test on all 6 injectors leaking around stems, got 6 in a box ready to be installed

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You have a neighbor that hates your guts?

In the famous words of Fred......Just sayin!

You’ve covered your bases pretty well and two machines with fuel, it would be a dirt trick to pull. 

Is your transfer pump original?

Did you have someone pumping your hand primer like a mad man while you watched those gallery plugs?

Remember the condition of RED’s transfer on his AI-370. It was still mostly running and putting a load of filings into his secondary fuel filter. A scenario like that, running failure, could be an issue? Not sure if he was seeing fuel in oil via pump driveshaft seal though....

 

Edited by Mack Technician

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On 9/26/2019 at 12:24 PM, Mack Technician said:

You have a neighbor that hates your guts?

In the famous words of Fred......Just sayin!

You’ve covered your bases pretty well and two machines with fuel, it would be a dirt trick to pull. 

Is your transfer pump original?

Did you have someone pumping your hand primer like a mad man while you watched those gallery plugs?

Remember the condition of RED’s transfer on his AI-370. It was still mostly running and putting a load of filings into his secondary fuel filter. A scenario like that, running failure, could be an issue? Not sure if he was seeing fuel in oil via pump driveshaft seal though....

 

Actually pulled the fuel filter and put dye, then started the truck let it run for a minute. took off the feed line and put a regulator and set air pressure @80psi and plugged return line. let it sit over night found that all 6 where leaking changed seals did a retest, but was really hard to tell where the dye was coming from. could have been left over from the first test. just got another sample back today al-400 with fuel dilution. the fuel plug had actual back out on it ,and was leaking fuel outside the cover  

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So I am miss understanding is the new fuel sample clear or not?

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15 minutes ago, fjh said:

So I am miss understanding is the new fuel sample clear or not?

"not" went from 5.3 to 8.3 in 225 hours with new oil.

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You guys sound like you have these engines figured out. That being said, are you following protocol when installing these EUP's? Unless your a huge fleet(or dealership) you shouldn't be seeing this many chronic, consecutive, fuel-to-oil cross contamination issues?    

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Did you test with the die after you replaced the o rings? Your positive the fuel ain’t coming from the transfer pump!?

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17 minutes ago, Mack Technician said:

You guys sound like you have these engines figured out. That being said, are you following protocol when installing these EUP's? Unless your a huge fleet(or dealership) you shouldn't be seeing this many chronic, consecutive, fuel-to-oil cross contamination issues?    

we have mack trucks impact, not sure what protocol is,but my boss doesnt want to waste money on parts. yet he'll waste money on oil and filters

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27 minutes ago, mhotrodscooter said:

we have mack trucks impact, not sure what protocol is,but my boss doesnt want to waste money on parts. yet he'll waste money on oil and filters

Rotating Cam till your on the low circle of the fuel lobe, pulling the EUP down evenly with two drivers simultaneously....or, as I usually do, get it on low circle and place a large seal bar against the top of EUP near pump body's center and compress it into the bore then run a bolt down to hold it in place. Clean the taper cut of the bores upper rim, making sure rust is removed and everything is lubed with clean motor oil. Mack wants new bolts every go-round.

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19 minutes ago, fjh said:

Did you test with the die after you replaced the o rings? Your positive the fuel ain’t coming from the transfer pump!?

yes but had dye from the previous test, didnt take the extra steps to try and old dye washed away. it wasnt coming from the pump when i had the pan off. thats not saying its not coming from it now though.  its got almost 2000hrs on a set of new eup pumps

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14 minutes ago, Mack Technician said:

Rotating Cam till your on the low circle of the fuel lobe, pulling the EUP down evenly with two drivers simultaneously....or, as I usually do, get it on low circle and place a large seal bar against the top of EUP near pump body's center and compress it into the bore then run a bolt down to hold it in place. Clean the taper cut of the bores upper rim, making sure rust is removed and everything is lubed with clean motor oil. Mack wants new bolts every go-round.

yes sir.. would you think mack just had a bad batch of eup remans in that year

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I haven’t seen many reman eup s  fail!

However  I’m not a huge fan of Mack reman parts either poor quality workman ship is rampant. OR low /loose rebuild specs!

just me  maybe!🤔

Edited by fjh

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2 hours ago, mhotrodscooter said:

yes sir.. would you think mack just had a bad batch of eup remans in that year

Don’t know, I wouldn’t have anything to base it on.

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