Think we finally are getting close to addressing all the issues that are inevitable on a 18 year old machine.
The engine never felt "right" soft on power? Most would think it's fine.
Turned out the cam sensor and ambient air pressure sensor really were noticeable.
Coach used to bog down up slight interstate grades at sea level at 60. Drop back and try to pull in the same gear. Without the mode on it would downshift to fifth. Ok but not impressive. Had to throttle it hard and run a lot of 100% load on the silverleaf up the short small grades. 7.5mpg
Same drive, same tow. Pulls the grades at 70 without a downshift needed and 90% load max.
Silverleaf shows 8.6 mpg over the short rode recent mpg.
Funny enough the short term mpg shows better at 1450 rpm at 69 mph versus 1350 and 60 mph.
Engine is drawn down easier at 60 up grades versus 70. More hp? Same torque roughly.
Was thanking cm and ray for a 70 mph coach setup.
Part throttle is noticeably stronger, interesting that the higher hp works better with the roughly the same torque curve.
Plus the 6 new xza-3 "h" tires at 100 front and 90 rear are quieter and less sharp riding and turn better and steer straight.
Fuel lines and a Parker fuel filter/pump.
Wheel seals and tighten the front bearing and replace all the torn grease seals in the front steering.
Centrimatics went in with unbalanced tires. Perfect.
And running the rack on the valves and adjusting the injectors.
That and the new koni's FSD's ride control is exceptional. Great roll resistance and big dip control while not kicking on the crossing sharp edges.
A keeper before all this but even more now. No tow and flat ground and no wind I wonder if it might get better than 9mpg.
Newer VIP steering wheel helps the hands not fatigue like the original.
Good for another 100k miles.
Had a grin today that was hard to wipe off. Good bones on old foretravel coaches help make the coach bucks worth spending.
Only way to justify the $ is to drive the money out yourself.
The help here and the info we all share makes this posdible for non rich people like us.
Serious about the better hill pulling and the mpg at 70 versus 60. Weird.
Oh and had the rims professionally polished out and new caps and nut covers.
Bob,
My guess is that the coach is heard for Engine max torque (most efficient in a diesel engine) at 70 MPH. Only explanation that makes sense short of hallucinations!
:-) fun toy! did you grab resonator yet?
I have had a 5050 resonator for more than year. one step at a time has worked well so far.
If it improves the performance even more I will be happy.....
No it is not wierd. Find the cummins dyno plot for your engine. Check the RPM at 70 vs 60. It's HP that matters, NOT torque. You are limited with only 6 gears. It's hard to get the RPM right in the narrow diesel power band.
My 8.3 makes max hp at 2200rpm. In 6th: 1600 is 66mph, 1700 70, and 1800 75. It will loose less speed on slight hills going 70-75 than it will at 65mph. Why? See my gearing thread and look at the dyno plot. Much more HP is available at 1800 than 1600rpm. Torque is irrelevant banter. HP is all that matters.
Nuts.. pc
spell check!@!!! geared, not heard!!!
I have a recent-to-me 1997 320 as well. Tell me more about the cam sensor and ambient air pressure sensors. Photos to help me locate them, please. Cost to replace them, as well.
Mine have not been replaced nor checked in at least a decade or more.
Thanks,
Steven
I did not do the work. The cummins dealer did.
They are both outside the engine. Not expensive.
You could hear the erratic idle from the rear of the coach with it running.
ALL fail. Metal potted with plastic for the dual pickup cam position sensor.
New one is all metal at the tip.
No backup unlike the ISM I understand have.
Main and spare pickups were in the same housing on ours.
Oil soaks the insides shorting them out or they fire at the wrong time.
No codes in the computer from this.
Shorted out completely it's a tow in to the shop.
Steve,
The part numbers that I have for our Celect should be the same as yours. The #4902720 is your ambient air pressure and the 4921501 is your intake manifold pressure sensor. The 4326596 Cam sensor fits a lot of Cummins engines and is one item that you should carry with you as a spare. One word of caution to those who have the M-11 Celect plus that is the same vintage you still need to double check with your engine # prior to buying parts as a spare.
As a side note the cam sensor has a primary sensor and a back up all in that one piece. That is the reason it has 4 wires, 2 for primary & 2 for back up. Between the sensor and your ECM it can swap back and forth if primary fails. With it swapping back & forth can cause a misfire, miss, and improper injection time as the computer don't know what position the engine is in.
Here is the best pic. I could get of the cam position sensor. It is hid down behind/under your air conditioner compressor. The first is of the plug looking through the belts. The second is the sensor looking from front of coach to the rear.
http://www.foreforums.com/index.php?action=dlattach;topic=22487.0;attach=26513;image
http://www.foreforums.com/index.php?action=dlattach;topic=22487.0;attach=26515;image
Your ambient air sensor depending on which sensor you have it should be tied to the wire loom that runs down the left side of the valve cover. The first 2 pics.
Your intake manifold pressure sensor is screwed into the intake manifold on side hole that is in the manifold close to the trans. end of the engine. The 3rd pic.
As far as cost will depend on whether they are aftermarket, Cummins, or eBay.
Pamela & Mike
Well the first 2 pics. didn't attach like I thought they would but you can still see what we are talking about.
Thanks Mike for the great information.
Steve
Sounds great! Enjoy. They are a quality coach for sure
Mike,
I have the sensors replace except for the ambient air pressure sensor, cannot locate it?
Can you please call me when you have time?
Steve Green
740-973-3134