For you series 60 guys or anybody else we are traveling with friends that have 60 in their Prevost,here is the problem today his boost went away no codes show with the Pro/Link or flash on the dash.
We have cleaned all connections , pins, checked the turbo,air cooler for leaks and even changed the sensor the silly thing will loose power no black smoke no boost pressure but you can turn the cruise control and the boost goes up to 30 lbs fairly easy
My 60 series guru is out of the country and won't be back for a month how about it Jim or Ken what the hell is going on with this 14L series 60, Prevost Tech was no help it was a waste of 30 or 40 minutes
I am completely lost on this it has to be simple it just started after we stopped for some BBQ it will get up to speed in 5 or 6 miles without much power
The guys at Stewart and Stevenson tell me it has to flash a code believe me this one will not we need some help S&S is booked for 2 weeks in advance in Houston got ideas guys and thanks for any help :'(
Are you getting throttle counts on the reader when you step on the throttle? Maybe the tps is kaput! Cheers Gerry
Is it a fuel starvation problem, that will not allow boost and will not produce a code.
If you get power on cruise ,it doesnt use the tps. no tps, no throttle, no fuel no power. Cheers Gerry
The TPS is a real possibility, but it should set a code, that doesn't mean it always does. Here's a wild guess, if you have a DDR or any other way to switch ratings try a different rating. Most ECMs have at least 2 ratings, 0 is the highest HP, 1 is slightly lower and so on. Anything that would normally cause that problem should set a code. Depending on the ECM program it can operate on a different set of parameters when on cruise control, an example is the 430/470 HP we see on some of the DDEC IV engines. It's a long shot but there could be a problem with the ECM program that's why there is no code. Switching to a different rating will use a different set of timing, pulse width, smoke control and desired boost tables that are stored in the ECM program for that rating. I'm doubtful if that will help, but it seems you checked the normal stuff. I'm guessing this is a DDEC V EGR engine.
I usually think of the most complicated thing and as you said it's most likely something simple we haven't thought of yet.
Ken
Clifford, I know you said that you checked the turbo... However, I would tug on the wastegate rod to see if it hasn't broken.. You could also have a seized gate/shaft (if it's seized in the open position it's dumping all the boost).. A rod that's broken will blow the gate open.
I didn't read that it was a 14 liter!!
I pulled into a rest area with everything running fine, when I tried to leave the coach wouldn't pull out of the parking space. After trying everything else including changing the ECM we found it was the TPS. Didn't throw any codes and checked fine with a tester.
Jack
Most Freightliner and Western Star dealers are also Detroit engine specialists. If you're getting full boost on cruise control, the gas pedal is the first that comes to mind-but that's probably to simple. Good Luck, TomC
Have to agree, sounds like TPS. Another fellow has been having intermittent problems with his coach - similar symptoms. As I recall, he has replaced the TPS once.
I recommended that he disconnect all the connections and spray them with contact cleaner and plug them together, then repeat several times. I have not heard an update from Ed since he tried that "fix". Not sure if no news is good news.
Jim
The TPS count is on the money but we are going to change it anyway and see still no codes with Pro/link,DDR or flashing Jim I have cleaned every connection on this thing 1/2 dozen time I own stock in CRC now
We stop at Prevost in Houston off I 10 the guy worked for about 1 hr and said take to a DD dealer he didn't know what was causing it, the thing is perfect on cruise but the cruise doesn't do much good in traffic ??? it is a DDEC V Ken and he has had nothing but trouble with it 2 turbos and 5 injectors over the last 2 years
Well, this is a pretty good puzzle. Be sure to let us know what the solution is (short of dynamite or a match).
Jim
Quote from: luvrbus on May 24, 2013, 10:20:14 AM
The TPS count is on the money but we are going to change it anyway and see still no codes with Pro/link,DDR or flashing Jim I have cleaned every connection on this thing 1/2 dozen time I own stock in CRC now
We stop at Prevost in Houston off I 10 the guy worked for about 1 hr and said take to a DD dealer he didn't know what was causing it, the thing is perfect on cruise but the cruise doesn't do much good in traffic ??? it is a DDEC V Ken and he has had nothing but trouble with it 2 turbos and 5 injectors over the last 2 years
The guys that work on the 14's say the N3 injectors don't usually give much trouble. If the owner is OK with an EGR delete that is supposed to reduce carbon/soot build up on the vanes in the VNT turbo. The vanes stick and set a code even though the turbo is actually OK. Another benefit of no EGR is a much longer engine life. The recirculated exhaust gas has soot in it which mostly ends up in #6 and wears that cylinder prematurely, then the blowby with soot in it gets in the oil and wears the rods and mains. This information is from a couple of guys who work on Detroit engines every day. Almost forgot, EGR delete usually equals about another 1 MPG.
Ken
It won't pass emissions in Phoenix with the EGR delete Ken we thought about it as he has had to replace the EGR valve
Tomorrow I going to do a hp set to 1 on your advice and a couple of others and see if that helps, don't you just love the future if this was a old mechanical 8v92 or a 425 Cat would not be a problem for me
He would love 6 mpg right now it 5 to 5.5 mpg
Do you how the emissions people check the ERG system?
I hear you about the mechanical engines, I live in both worlds, I like a lot of things about the electronic engines but if you have one with an odd problem all that good stuff doesn't matter much.
Ken
They check the ECM versions for any deletes you have a idea on how we can delete and how they could not detect they give you a few deletes that do not pertain to emissions for that emission year model
I have the manual for the emissions telling what is allowable and what is not, CA does the same crap it bleed over to AZ a few years back when LA moved here just certain shops that can do emissions on diesels most are truck dealers and dumb as a box of rocks one told Mike he was going to need testing on a 8v71 before he could plate it.
Just 3 counties in AZ have emissions testing and he lives in one no test no plates, I live in one that doesn't have the testing lot of people live at my address lol even Don Fairchild
California is strange. I have a '77AMGeneral bus, '85 Kenworth truck now registered as a motorhome, and my '84 Mercedes 300 Turbodiesel. Maybe they're all to old, but have never had to have them smogged or smoke tested. Good Luck, TomC
Quote from: luvrbus on May 24, 2013, 12:46:23 PM
They check the ECM versions for any deletes you have a idea on how we can delete and how they could not detect they give you a few deletes that do not pertain to emissions for that emission year model
I have the manual for the emissions telling what is allowable and what is not, CA does the same crap it bleed over to AZ a few years back when LA moved here just certain shops that can do emissions on diesels most are truck dealers and dumb as a box of rocks one told Mike he was going to need testing on a 8v71 before he could plate it.
Just 3 counties in AZ have emissions testing and he lives in one no test no plates, I live in one that doesn't have the testing lot of people live at my address lol even Don Fairchild
The ECM calls for EGR operation between a range of RPMs, say 1200 to 2000 RPM. That can be raised to say, 3900 to 4900 RPM then it's unlikely the engine will ever rev high enough to call for EGR operation, I mean really unlikely. Nothing is actually deleted. I don't know we could try it.
Ken
Thanks Ken we are going to give it a try if they don't like it when tested next year they have all the goodies to set it back,now that leaves me wondering how could they tell he needed a new EGR valve last year was that done by dropping the operation rpm ? it seemed to work fine
Clifford, I don't have a DDEC V book but on some of the IV wiring harness they have three fuses not two and It looks like they pull cruse control from that third circuit, maybe Ken could look at that on his schematic see if some of the V's are the same. Knowing some of BK's issues I would check and make sure it doesn't have one more fuse in the batt box and all the ground are good. I may be off base but who knows.
Don
Hello; just some suggestions or maybe WAGs... Please check all fuses and any that may not seem to be related. Ace Rossi went thru hell with his engine only to find some blown fuses. THat was a different problem because the fuses were for the injectors. YOu may have a circuit that has been unintentionally fused by prevost or previous owner??
See if any other inputs only work when in cruise. If it is not a fuse than it is a ground wire off or deteriorated somewhere. I agree with the previous poster.
Regards mike
I just took my bus through emissions testing today. Maricopa County. 8V71N, It blew a 1.5 Diesel testing is only going to get tighter as the EPA clamps down.
After changing the TPS still no joy,set the Hp to 1 still no joy so I went to the base at Ft Hood and borrowed a ECM from the rebuild contractor he did the setting for a on road 515 hp DDEC V all is normal he set the EGR to work at 3200 rpm said that should be good if it ever turned 3200 there would be nothing left anyway
Ken I never knew the military has a different DDC software than the public now I know how Cole does some of his off the wall stuff with the 60 series that would be nice software to have but the guy was not giving me a copy lol those guys have no rules they were testing series 60 running on straight bio-fuel man did they stink