M35 Fire truck WOT 2000 rpm 44 mph ... what's up?

[scootertrs]

OK... took her out for a good shake-down... starts, stops, runs smooth. New fuel filters, full travel on the injection pump, still max speed is 44 mph and 2000 rpm empty. Plenty of power. Everything looks OK and she feels like she will run until the EOD like this, but I would like to get the 53-55 mph other members are getting... any ideas?
Thanks

 

[BFR]

-pickup on the intank pump crusty?
-air filter clogged?

 

[Josh]

Speed verified by GPS?, Someone may have ajusted the govener also.

 

[scootertrs]

nope... good flow from pump and back... just the right amopunt of smoke... new filters all around...

 

[cattlerepairman]

Check fuel line for crushed areas, especially in front of axle/under radiator.

 

[63sierra10]

Speed verified by GPS?, Someone may have ajusted the govener also.

Ditto I would check that the governor hasn't been adjusted.

 

[jwaller]

what does your egt do when you hit max speed? it it goes down then you are not getting enough fuel. I would go thru the TMs and make sure the gov is set correctly.

 

[jasonjc]

Is that loaded or emty??? How much more does that weigh than a M35A2??

 

[scootertrs]

will check the gov... she runs smooth... no surging nothing bad happening except ... 44 mph

not quite sure how to check the gov but if all else fails I will check settings... I believe I have the TM for that...

the thing is... she starts with first spin of the engine

anyone off the top of their head know what the psi for the pump out of the tank is supposed to be... how about the governor pressure?

 

[WillWagner]

IIRC the low pressure should be 7 to 10 PSI. With the engine stopped, make sure the throttle lever is going to full throttle.

 

[Ruppster]

I don't know what the exact redline is for a multi-fuel engine but from what I remember it is higher then 2,000 rpm. Will the engine do more then 2,000 rpm if you rev it in neutral? If not I would take a look at the governor adjustment.

If your engine is reaching the proper redline could you be in 4th gear and not 5th (remember the overdrive trans have 4th and 5th swapped)? Or could you have a 5 speed from a gas powered truck where 5th gear is direct and there is no overdrive?

Ruppster

 

[stumps]

I don't know what the exact redline is for a multi-fuel engine but from what I remember it is higher then 2,000 rpm. Will the engine do more then 2,000 rpm if you rev it in neutral? If not I would take a look at the governor adjustment.

If your engine is reaching the proper redline could you be in 4th gear and not 5th (remember the overdrive trans have 4th and 5th swapped)? Or could you have a 5 speed from a gas powered truck where 5th gear is direct and there is no overdrive?

Ruppster

The top speed for the truck in 5th gear is 56MPH. The top RPM in any gear is 2600RPM.

[ 56MPH / 2600RPM ] x 2000 RPM = 43MPH

He is in 5th gear, and his MPH is appropriate for his engine speed.

I vaguely remember something about fire trucks and a reduced governor speed, but it is firmly entangled in the dense fog... Could very well be muddled...

Put the transmission in neutral, and slowly bring the engine up to full throttle, or 2700RPM, whichever comes first. At full throttle, your engine should top out at around 2650-2700RPM. If it does, you are losing power to some other cause:

1) incorrectly adjusted IP max fuel rate
2) restricted fuel flow.
3) dragging brakes
4) mixed sized (wear) tires on rear axles
5) ???

If you want your truck to go faster than 43MPH, you are going to have to get the engine to go faster than 2000 RPM... (well duh!).

-Chuck

 

[mistaken1]

There is an engine TM that goes through the entire engine troubleshooting/adjustment procedure step by step to get the no load RPM to the proper setting then to get the loaded RPM to the proper setting.

http://old.steelsoldiers.com/index.php?module=pagesetter&type=file&func=get&tid=1&fid=file&pid=57

 

[Warthog]

There is an engine TM that goes through the entire engine troubleshooting/adjustment procedure step by step to get the no load RPM to the proper setting then to get the loaded RPM to the proper setting.

http://old.steelsoldiers.com/index.php?module=pagesetter&type=file&func=get&tid=1&fid=file&pid=57

You beat me to it. I was just about to post the LDS Troubleshooting Manual also.

Even though this manual is for the LDS and not the LDT, it stiil has some great infomation. It is the one I go to first.

 

[docfarmall]

Hummmm u sure your in 5th

 

[scootertrs]

Thanks Guys...

My plan of attack is going to be:

1. confirm tach is reading right by comparing to outboard digital tach.

2. If 1 is correct, then recheck fuel pressure from prime in tank pump

3. If that is correct, then check all lines to confirm no "squooshed" lines... technical term

4. If all that is good, then jump on the tech manual for the engine

BTW, I do not believe fire trucks are governored differently or lower than othetr trucks since in the specs they discuss the pressure/volume expected if truck is running at 2250rpm...

thanks for the help

 

[scootertrs]

Geez doc... lets see... 1,2,3,4... yep its in 5th

Know how I know??? I ran out of fingers

Hummmm u sure your in 5th

just kidding... that is the ticket.... not that I haven't done that before... but usually involves a little pictogram of a trailer in the dash of my Chevy 2500...

Boy, I tell you what, you were right on the money when you "guesstimated" the auction price of that fire truck... It was just too rich for me right now... maybe after I get my tax refund

 

[DDoyle]

BTW, I do not believe fire trucks are governored differently or lower than othetr trucks since in the specs they discuss the pressure/volume expected if truck is running at 2250rpm...

thanks for the help

You are absolutely correct - fire trucks are governed no lower than the others. I have a Class 530C myself, with less than 1000 original miles on the original engine, and it will easily pull away from my other trucks (and, to my knowledge, there has not been a wrench put on the engine since it was made).

Are you SURE that the full-torque (transfer case) PTO is completely disengaged?

By the way, if your truck has a Waterous pump, they'll supply the manual at no charge - I've never tried for the Hale manual.

Best wishes,
David Doyle

 

[dmetalmiki]

Ahh...there's a whistle! My son fitted a "C" turbo one night as a project!..sound great..goes much better.. (and it was allready quick before)..

1200x20's (still twinned) and fronts out each 4 1/2 inches. for that aggressive stance.

http://www.youtube.com/watch?v=OyxIJUq7rww if the link don't work go on

utube dmetalmiki my m45 firetruck

 

[saddamsnightmare]

April 19th, 2010.

Scootertrs:

Could it be a possibility that your truck might have 5th gear still in it as an underdrive gear? The normal top end of an unconverted M35A2 with 5th as an underdrive should be in the 44-45-46 MPH region, if what all I've heard and read is correct. Besides, how many deuce firetrucks ever got off base?