CML Service Posted February 8, 2008 Share Posted February 8, 2008 Hi folks, I'm looking for a little info here. I'm working on a 2000 Ford F750 with a Cat 3126 210hp. Truck seems to run OK and can achieve 70mph road speed. But as soon as it sees a hill it starts slowing down. All filters are fresh. As a matter of fact it was just at Ford for this problem and they said "we fixed it, the filters were clogged". Truth is filters had less than 100 hrs on them and the problem is still the same. I checked with the local Cat dealer they didn't seem very hopefull. They told me they don't have a chassis dyno so they couldn't check advertised HP. All they said was we could look into it for $110 per hr. They did hint at possible boost press problem though and said press should be aroud 20. So I hooked my laptop up to the truck and even though I only have IH software I could read some engine info. I found on a road test max boost was 19.75 and as soon as you hit the hill the boost started dropping. When you got down to 45mph the boost was only 15.35 is this normal? Any suggestions? We have other trucks (IH 215hp) that will walk away from this one even when pulling a trailer. This is a problem we recently noticed while traveling in convoy to upstate NY to do storm related power restoration. Since I'm the company mechanic I'm the last in the convoy and this problem truck gets us way behind. Chuck Quote Link to comment https://www.bigmacktrucks.com/topic/3396-cat-3126/ Share on other sites More sharing options...
GearheadGrrrl Posted February 8, 2008 Share Posted February 8, 2008 By way of a really dumb sweetheart contract the Postal Service ended up with a bunch of 3126 powered "toy Freightshakers" a few years back. Even bobtailing they were the slowest trucks in the fleet, and the slightest upgrade or headwind would have them down to 40 MPH or less. Quote Link to comment https://www.bigmacktrucks.com/topic/3396-cat-3126/#findComment-16858 Share on other sites More sharing options...
other dog Posted February 9, 2008 Share Posted February 9, 2008 I feel your pain...many times over the years i've taken a truck back to the dealership (usually Truck Enterprises,Roanoke,Va.) knowing something wasn't right only to be told "there's nothing wrong with it-it's supposed to be like that". Many times. Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/3396-cat-3126/#findComment-16903 Share on other sites More sharing options...
de37champ Posted February 9, 2008 Share Posted February 9, 2008 Hi folks, I'm looking for a little info here. I'm working on a 2000 Ford F750 with a Cat 3126 210hp. Truck seems to run OK and can achieve 70mph road speed. But as soon as it sees a hill it starts slowing down. All filters are fresh. As a matter of fact it was just at Ford for this problem and they said "we fixed it, the filters were clogged". Truth is filters had less than 100 hrs on them and the problem is still the same. I checked with the local Cat dealer they didn't seem very hopefull. They told me they don't have a chassis dyno so they couldn't check advertised HP. All they said was we could look into it for $110 per hr. They did hint at possible boost press problem though and said press should be aroud 20. So I hooked my laptop up to the truck and even though I only have IH software I could read some engine info. I found on a road test max boost was 19.75 and as soon as you hit the hill the boost started dropping. When you got down to 45mph the boost was only 15.35 is this normal? Any suggestions? We have other trucks (IH 215hp) that will walk away from this one even when pulling a trailer. This is a problem we recently noticed while traveling in convoy to upstate NY to do storm related power restoration. Since I'm the company mechanic I'm the last in the convoy and this problem truck gets us way behind. Chuck I have a 3116 in a topkick roll back truck, i would say the 3126 just took its place, i rebuild the motor to specs and had the biggest dog in the world, Now tell me if that motor has a injection pump or just that fuel body thing on the upper left side of the motor, i did 3 things to mine to get it to run, i can run and keep up now, i had a D2 cat on in WV and could top hills on the highway running 70, i might be able to help you a little, Quote Link to comment https://www.bigmacktrucks.com/topic/3396-cat-3126/#findComment-16907 Share on other sites More sharing options...
CML Service Posted February 10, 2008 Author Share Posted February 10, 2008 I have a 3116 in a topkick roll back truck, i would say the 3126 just took its place, i rebuild the motor to specs and had the biggest dog in the world, Now tell me if that motor has a injection pump or just that fuel body thing on the upper left side of the motor, i did 3 things to mine to get it to run, i can run and keep up now, i had a D2 cat on in WV and could top hills on the highway running 70, i might be able to help you a little, Yes I believe the 3126 took the place of the 3116. The 3126 is all electronic with unit injectors. Chuck Quote Link to comment https://www.bigmacktrucks.com/topic/3396-cat-3126/#findComment-16918 Share on other sites More sharing options...
de37champ Posted February 10, 2008 Share Posted February 10, 2008 Yes I believe the 3126 took the place of the 3116. The 3126 is all electronic with unit injectors. Chuckon my 3116 there is a little steel line about 1/8 inch that runs from the intake manifold to that fuel govener, i put a check valve between them two not letting the air back into the manifold, then on the turbo there is a waste gate, i put a plug in there so it won,t open up, 3rd on the fuel rack inside of the valve cover i gave the fuel rack 2 complete turns counter clockwise giving it more fuel, i have been around heavy equitment all my life plus pull tractors so i am all the time playing with horse power, i did make me some fittings and put manual water temp. and oil press gages on it thu also i put a tach on it from jegs that runs off the alternator, the factory ones was way off, i hope this helps you out Quote Link to comment https://www.bigmacktrucks.com/topic/3396-cat-3126/#findComment-16934 Share on other sites More sharing options...
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