Turbo Boost on a series 60 ?

[luvrbus]

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  

[hargreaves]

Are you getting throttle counts on the reader when you step on the throttle? Maybe the tps is kaput!  Cheers Gerry

[Boomer]

Is it a fuel starvation problem, that will not allow boost and will not produce a code.

[hargreaves]

If you get power on cruise ,it doesnt use the tps. no tps, no throttle, no fuel no power. Cheers Gerry

[Hard Headed Ken]

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

[Zeroclearance]

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.

[Zeroclearance]

I didn't read that it was a 14 liter!!

[blue_goose]

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

[TomC]

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

[rv_safetyman]

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

[luvrbus]

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

[rv_safetyman]

Well, this is a pretty good puzzle.  Be sure to let us know what the solution is (short of dynamite or a match).

Jim

[Hard Headed Ken]

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

[luvrbus]

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

[Hard Headed Ken]

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