{{{3/13/10}}} Epilogue posted on page 3
{{{ 2/28/10}}} retitled and posted update later in this thread}}}
2/25/10. I am starting a new thread, as the old one (http://www.busconversions.com/bbs/index.php?topic=14591.0 (http://www.busconversions.com/bbs/index.php?topic=14591.0)) was getting too long.
Well, today with fear and trepidation (snow in driveway and Eagles are not that great on traction) I decided to make my fourth test drive.
Since my last drive, I had tested the fuel supply capability (over 60 GPH) and rechecked the charge air plumbing connections (some small leaks found).
We had to make a couple of laps around the subdivision (what must the neighbors think?) to get the bus up to temperature. On the third lap, the water temperature was 192 and the highest boost I could get from the engine sensor (via SilverLeaf) was 14 PSI. However, my mechanical gauge was reading 21 PSI!!!!!
So, I think I have a boost pressure sensor problem. In the last thread we discussed that DDEC III boost sensors are more desirable. In my case, it is even more desirable since I have my old DDEC III unit from the original engine. I looked and it is a GM product with the numbers 629 6036 stamped in it. It has a 3 wire plug.
It was mentioned that some adaption was required. Does anyone know what I will need to do the adaption. I do not have the connector for this boost sensor. If it is different from the DDEC IV plug, can someone tell me where to find the DDEC III connector?
Thanks again for all the help!!!!!
Jim
Jim,
You better have found the problem because, and I think I speak for many busnuts here, I"M GONNA GET AN ULCER from watching this unfold online.
I've prayed.... I've racked my brain... I've ran downstairs after work to my computer to see if the "remedy" had been found.
So Jim, would you, for all our sake, fix this darn thing once and for all!!!
I'm kidding of course...sort of. Well I'm kidding except for the whole running downstairs, racking my brain part.
Sincerely hoping that you have solved one of the great mysteries,
Rick
Jim
I will check tomorrow and see if I have a plug for the boost sensor. You are still low on boost, need to check the exhaust for leaks. I know you don't want to take that cover off but I'll bet that is where you well find the problem.
Jack
Jack, I plan to remove the blankets in the near future. I had Pat start the engine this time and did not hook up the coolant heater. I watched the exhaust manifold and there was smoke coming out. Not very much, but enough that it needs to be looked at. Now that I have a new lead, I want to pursue it first.
Jack, thanks for the offer. I did find a connector on Ebay (400059243771). I will pull my sensor tomorrow and see what I have to do. I will order the connector if I need it for the conversion.
Yes, the 21 pounds boost is low, but I have to wonder: If the ECM thinks that the boost is low, will it pull back the fuel? The hill that I test on loads the engine pretty good, but the curves do not let me build full engine RPM and thus full boost.
Jim
Jim,
I have also been praying for the man upstairs to help you.
I know I will have lots of problems with my mechanical engine, but keeping up with your threads on this makes me know for sure I will never own a series 50 or 60. I don't have the patience or the time.
John
PS How much is a new booster sensor? $1000?
John, sensors don't cost that much but like Cole says a 80 dollar sensor can cost 1200 bucks after the dealer gets through with you.
Jim is doing it the old fashion and economical way remove and replace and I sure hope he doesn't loose all his hair over this deal
good luck
Wow Clifford that hurts ;D. For those who have not met me, I have no hair to loose ;) With my beard, my daughters tell me I have my head on upside down ::)
Thank goodness I am an engineer and have done troubleshooting all my adult life. This has almost been fun - especially now that I have the time to pick away at it. The d@#$ weather has been a pain (more snow tonight), but when this is all over and we are on the road again, it will all seem trivial (till I go back and look at about 6 threads that are multiple pages long :o :o).
Pat has made the last two test drives with me and she said it felt soooo good to be in her seat and riding in the bus. We are both way more than ready to hit the road!!!!
Jim
Jim,
This will be one of those infamous "Laugh Later BusNut Moments". You know, where you weren't laughing at the time but later on , sitting arouind a fire with other busnuts, you will laugh and say something like "yeah, remember that time ........? Best of luck on tracking this down. I would try to send you some of our warm weather, but I think someone done stole it, 36 degrees this morning with a light dusting of frost BRRRRR! Jack
Quote from: rv_safetyman on February 25, 2010, 04:02:37 PM
Jack, thanks for the offer. I did find a connector on Ebay (400059243771). I will pull my sensor tomorrow and see what I have to do. I will order the connector if I need it for the conversion.
Jim, that connector looks like a standard Delphi Weatherpack connector. I would bet that any diesel shop that works on a lot of Series 60 engines will have the tools and parts to attach on of these connectors to your wiring.
I would not recommend buying a pigtail because then you have to splice in the pgitail. I would be willing to ship you my Weatherpack crimper along with the parts to make up your own connector. Dina uses a fair number of these so I bought the crimper and a whole huge selection of the terminals and other parts to make these up myself. I used Weatherpack connectors on all of my LED lighting in the rear just in case I ever have to replace a light.
Jim
If your Silverleaf (which displays DDEC info) is only at 14 psi - then most likely - your DDEC-III input is actually at 14 PSI (or about 2.25 volts output on your Turbo boost sensor - it sould be about 3.8 volts for 20 PSI boost)
I believe the TURBO BOOST SENSOR output is used to deterrmine (WHERE IN THE INJECTOR FUEL MAPS) you need to be - with that low reading the DDEC limits the fuel for ithe injectors to avoid black smoke.
Here's all the research that BILL GERRIE did on a work around for ddec engines that had ECM programs that were factory set to avoid ANY smoke -
Bill proved that if your tell the ECM your have more boost - It dramatically changes acceleration (IN engines that have NO SMOKE LIMITERS in there ECMS)
THAT CERTAINLY SEEMS TO BE YOUR PROBLEM (actual gauge boost = 21 PSI -- DDEC boost reading 14 PSI) - CHANGE THE DAMN TURBO BOOST SENSOR !!!!!!!!
HERE'S BILL'S DATA
9/24/07
Hi - Good News for DDEC (I-II-II-IV) Owners with poor acceleration from a stop
I'm talking about Detroit Diesels with a painfully slow response when starting from a dead stop - seems their DDEC is set with some kind of "smoke control" / "Throttle Delay" / "??" option - they do not smoke when you mash the throttle down
DDEC I -
Thanks to the work of Butch Williams - Luke at US Coach stocks an EPROM replacement for approx $100 that will cure most N.J. MCI DDEC I of their poor acceleration. DDEC I's have a replaceable EPROMS and are not programable
Note - The DDEC II-IV Fix (see Below) may very well work on DDEC I's (We Just never tested the Fix on DDEC I's)
DDEC II, DDEC III, DDEC IV,
Bill Gerrie and Pete Papas have worked on this problem - Via long distance phone call Between Daytona and Toronto - Thank goodness for "Unlimit USA/Canada phone plans) Bill used his PROLINK to verify and test the settings and ideas -
First a little history
The D/D DDEC TURBO BOOT SENSOR
old part#--> 16070629 new part#--> 23528418
is a 3 pin solid state IC device
pin A = Sensor Return
pin B = Signal Line
pin C = +5 volt supply line
pin B - operating range - approx .5v to 4.75 - voltages outside this range will cause a DDEC Fault
example
pin B @ 1.00 volts = approx 00 PSI Boost
pin B @ 2.25 volts = approx 10 PSI Boost
pin B @ 3.80 vollts = approx 20 PSI Boost
<>The PROLINK was used to verify the correct action of Bill's TBS without the modifications
<>Bill came up with a unique solution - A 100 ohm resistor between pin B (sense line) and C (+5 volts) - will pull up the voltage at the sense line (pin B) to what would be an approx 4-5 psi boost voltage level (as measured/verified with the PROLINK)
<>Just pull off the connector to the TBS and splice the resistor into the wires behind the connector
<>AS the actual boost pressure increases past 5 or 6 PSI the pull-up effect goes away - allowing normal TBS voltage levels
<>AT full boost the pull-up resistor has no effect
<>The net result is that the DDEC thinks that there is a little boost pressure available at IDLE and allows for more fuel to be delivered to the injectors upon acceleration
<>This does mean that if you mash the pedal - you will produce some black smoke- just use the throttle pedal wisely (especially in front of the smog control guys)
<>Idle still remained smoke free
***** UPDATE 130 OHMS seems to be the best solution **** 07/07/07
Pete RTS/Daytona
Your results may vary - use at your own risk !!
Ok, I think I have to admit that this is an electronic issue (Sonnie, you can call and rub it in ;D)
I talked a couple of times to Pete Papas today and he was helping me figure out how to hook up my original boost sensor (a GM boost/Map sensor) since has a different connector from the sensor on the replacement engine. As we both discovered, the sensor on the DDEC IV engines (not sure all) is quite different from the DDEC III sensors. The DDEC IV sensor off my replacement engine is a DD branded part (23522322). It bolts to the same opening as the DDEC III sensor.
Pete and I kept trying to think about why the replacement engine sensor would go bad. Did not seem logical. Turns out, I don't think it is bad.
****warning: what follows is engineering discussion :D :D :D****
I began to research the GM sensors and it turns out that there are several versions of what they call a Map Sensor (same part). A good reference is: http://www.robietherobot.com/storm/mapsensor.htm. (http://www.robietherobot.com/storm/mapsensor.htm.)
Some are only for normal induction engines in which case they are measuring vacuum. However, they also have versions that can read pressure in the intake manifold for turbo engine. For those engines they produce three levels of sensors (2.0, 3.0, and 3.3 bar). I have not been able to track down which unit I have, but I believe it is the three bar unit (3 bar equals 44 PSI absolute or 29 pounds of boost). That would be sufficient for my non-wastegate turbo. However, the wastegate turbo produces boost well into the 30 PSI range for most Series 60 engine thus the need for a different boost sensor.
OK, the plot thickens. Each sensor has a 5 volt input and the sensor returns a voltage based on the pressure it sees. Each sensor output range is from 0-5 volts FOR THAT SENSOR. So, a 2 bar sensor puts out 0 volts at full vacuum and 5 volts at 14.7 pounds boost. For 3 bar sensors, voltage output would be 0 at full vacuum and 5 volts at 29 pound boost.
I found one reference that says the DDEC IV (23522322) is a 4 bar sensor (43 pounds boost). Thus, it would likely have an output of 0 volts for full vacuum and 5 volts for 43 pounds boost (depending on the design, it could be 0 volts at no boost and 5 volts at 43 pounds boost).
It appears that the ECM is programmed so that it knows what boost sensor is being used. When I put my original ECM, it was programmed for the GM sensor (If I am correct about it being a 3 bar sensor, it would produce 5 signal volts at 29 pounds boost) but the actual sensor is producing a voltage of something like 5 V at 43 pounds boost. Obviously the DDEC IV sensor is putting out less voltage for the same boost as my DDEC III sensor.
All of that would explain why the engine (and SilverLeaf) think the boost is lower than it really is.
As Pete pointed out, the map sensor (boost sensor in the case of DD) provides information to the ECM to tell it how to fuel the engine. If the engine thinks the boost is low, it will look in the data table in the ECM and fuel the engine with less fuel.
*****end technical mumbo jumbo****
So the bottom line seems to be that I can run my old ECM with the DDEC III sensor and I should be fine. That causes two problems. First, when I put the wategate turbo on, the map sensor will not have sufficient capability. Second, I will need to cobble up the wiring harness somehow.
The best solution is to install the replacement ECM back on the engine (with the replacement DDEC IV sensor) and it should work just fine. That is pretty easy to do. I did check the replacement ECM with my Pro-Link and it has the J1939 port activated (for the AutoShift communication), so it should be a drop in.
I will test the "new" ECM as soon as our latest snow melts. There is another small storm on the way, so I am not sure when I can do the testing.
Optimistically:
Jim
Removed
Jim the first time that I worked with the problem of low boost was with a 4 turbo sensor. To find out if it was the boost sensor we used a pair of 100ohm restors across the boost connection's to tell the ecm that it had about 20 lbs of boost. You can see this on the silverlink, when you lie to the ecm. Then it will start with a lot of fuel because the ecm will give it all the fuel you want it to.
We did find the series 3 boost sensor did give boost reading faster than the series 4, but until you get rid of all the leak in the exhaust you are not going to have full boost. When you see that puff of smoke at start-up you know it has a leak. Nothing you do until that is fixed will correct the main problem.
Jack
Update 2/28/10 OK folks, I just took the bus on another drive and it seems that all is well. Pat did not go with me, so I did not record any data - I just wanted to make a quick test before the snow moves in again - to see if I had cured the problem. I saw 27 pounds of boost on the SilverLeaf and it had great power. I think we have found the problem.
Now, lets recap. My original ECM (a DDEC IV which I thought would interchange) apparently was programmed for the DDEC III boost pressure sensor that was on my original engine. When it saw the DDEC IV sensor, it was not able to read the correct/actual boost and that put the engine in a different part of the "Map" in the ECM.
Apparently I confused a couple of folks as to why there is a difference in the boost sensors and what it does to the ECM. So, I will try to explain with numbers that are not correct from an engineering standpoint, but they will serve as an example.
For talking purposes I will label the DDEC III boost sensor as a 30 pound boost sensor (close). The DDEC IV boost sensor is 40 pounds boost (approximately). Both put out a voltage of from zero to 5 volts for the full range of the sensor. Where I am taking some liberty here is that the boost sensors have an output from full vacuum to max boost, but that just makes it too confusing.
So, a real 20 pound boost on the DDEC IV sensor (in our example) puts out 2.5 volts (20 pounds if half the max boost of the sensor - again, using a simplified example). For the DDEC III sensor, the output voltage in our example would be 3.33 volts (20 divided by 30 for full range times 5 volts for full range). So the original ECM saw 2.5 volts from the DDEC IV sensor and said that is about 14 pounds boost.
When I matched the replacement ECM, which was programmed for the boost sensor on the engine, the problem was cured. The ECM correctly read the sensor, put the engine management in the correct part of the "map" and all was good.
I was not able to compare the mechanical gauge with the SilverLeaf, because the power was so good that I had to let off the throttle quickly in order to be able to make the curves.
So, now what will all you guys do for entertainment??? ;D :) ;)
Jim
Oh, i am sure that there will be someone else out there that has an electrical problem, it's just a matter of time. ;D Good to hear that you figured it out though. :)
Jim,
Glad to hear you got it fixed. I think I will just stay with my MUI engine. Jack
Quote from: rv_safetyman on February 28, 2010, 01:13:10 PM
Update 2/28/10 OK folks, I just took the bus on another drive and it seems that all is well. Pat did not go with me, ...............
Well - - there's the problem right there. Its a well known fact that wimmen shouldn't be around any machinery more complicated than a sewing machine or a vacuum cleaner.
Glad to hear you got to the bottom of it Jim.
Hmmmmm - what did I tell ya !!!!!
Lesson learned here a DDEC will control the boost pressure and a bad wiring harness will make a Eaton flash
good luck
QuoteLesson learned here a DDEC will control the boost pressure and a bad wiring harness will make a Eaton flash
.
You forgot the part about lost hair ;D
I can tell you for sure that if I had had hair before this whole episode, I would have lost it.
As I said in a previous post, in some perverse way, this whole trouble shooting process was somewhat "enjoyable" to this crazy engineer. It is terrible to be a bus nut and a crazy engineer all in one package.
Thanks again so much for all the great input. I know I learned a ton from you folks. I sort of know my DDEC a bit better than I did a few months ago :o
Jim
Great news Jim :), now what you need is a refreshing drive, like down to the rally in Texas ;). felt so bad for you as you did for me, now every body is happy. Whew! I think I need a trip to Disney or something like that :-\. Didn't someone say we'd have a good laugh when this was all over ;D ;D, I think I'll have a good cry first ;D Good work Jim as always :)
Van
Quote from: van on February 28, 2010, 09:48:16 PM
Great news Jim :), now what you need is a refreshing drive, like down to the rally in Texas ;). felt so bad for you as you did for me, now every body is happy. Whew! I think I need a trip to Disney or something like that :-\. Didn't someone say we'd have a good laugh when this was all over ;D ;D, I think I'll have a good cry first ;D Good work Jim as always :)
Van
Just drive on over to Franklin, TX you'll think you have been to Disney! (after meeting Goofy, Pluto, Mickey and the other busnuts that'll be there! ;)
;D BK ;D
Good News Jim! Now go for a long drive and enjoy the fruits of your labor!
I'm Sneezy by the way! ;D
Wow Jim, what a good feeling to have that over with! What a pain, but what a sucess! Congratulations.
Well, so much for the theory that the electronics will tell you what is wrong or "where it hurts". :o
There is no substitute for understanding the whole system & old fashioned troubleshooting. 8)
Even better when you have friends that will help troubleshoot.
As good as the electronic stuff is, there is something to be said for using old fashioned mechanical gauges to verify the electronic.
Now, does this mean you won't need heat in your shop? Since you'll be driving instead of working on it . . . ::) ;D
It is kinda hard for the ECM to know that a different sensor is being used than the one the ECM is programmed to work with. If the sensor was faulty the ECM would probably know that and report it.
Electronics are both a blessing and a curse. Electronics can make for far cleaner emissions and somewhat better fuel economy, but mechanics use them as a crutch instead of doing real troubleshooting. The first thing any mechanic will do these days is hook up their scanner. A lazy mechanic won't investigate further if the scanner shows no faults.
That was my point, electronics are only a part of the system - NOT the absolute answer. Seems most people think the scanner does all the troubleshooting work & tells exactly what needs to be replaced - that ain't so.
There are fewer & fewer mechanics out there today - they have been replaced by scanner readers who think replacing the sensor that flashed the code will solve the problem. :(
When you consider the reliability of the newer stuff combined with the disposeable goods mentality, then add in the wal-mart pricing minded customers complaining about how much the mechanic charges . . . .
Doesn't seem to be much demand for really good & experienced mechanics. :( :'(
I am not sure it is fair to lay all of the blame on electronics here. Recall that I was doing a "mix and match" here. I put my original DDEC IV ECM (albeit programmed to operate on a DDEC III engine) on the replacement DDEC IV engine. So, I really am to blame for the problem.
The reading I had done suggested that ECMs of the same vintage are interchangeable. Obviously not true. In hind sight, my move was ill-advised. However, my thought process seemed reasonable at the time.
Recall that the AutoShift has to talk to the engine. I did not want issues in that area, and chose to use the original ECM since I knew it talked to the transmission very well. As I said, I did not find any information suggesting that would cause a problem.
I am really glad that the process went the way it did. My next move was to put the replacement ECM back on the engine. If I had done that without learning about the difference in boost sensors, I would have missed an important piece of information. Replacing the ECM would have cured the problem, but I would not have know why.
Putting the replacement ECM in the bus is not just a drop in. It must be programmed for the specifics of the bus. The tire size and rear end ratio must be reprogrammed. In addition, some transmission information must be re-programmed. That can be done with a ProLink. I changed the tire size and rear end ratio, but there is some transmission calibration that is not correct, as I am not getting speed and have a fault code showing for that problem. I will need to figure that out, but should not be a big deal. I knew going into the conversion of ECMs that the replacement unit was programmed by DD for J1939 communication. That gave me some confidence that it would talk to the AutoShift and it did. If the J1939 had not been activated, I would have had to have that done by a dealer, as only the "factory" can do that .
So, the electronics did their job, and none of the sensors had failed. There was not a condition that justified a fault code. In the real world (not the crazy mixed up "world of Shepherd") this would not have happened.
Having said all of that, I still have not gotten my "see I told you so" call from Sonnie ;D ;D :)
Jim
Quote from: rv_safetyman on March 02, 2010, 07:36:29 AM
. . . .
So, the electronics did their job, and none of the sensors had failed. There was not a condition that justified a fault code. In the real world (not the crazy mixed up "world of Shepherd") this would not have happened.
. . . .Jim
I'm not so sure about that . . .
Many times I have received the wrong part - looked right, but wasn't. I've even had to pay for unnecessary repairs because the first part didn't fix it - $$$ later, the first part gets replaced again & the problem was solved.
My point was & is that there is no substitute for understanding the whole system. One can not simply rely on one tool to fix everything. One cannot trust all parts in the system to be correct - but that is where we must start & where total understanding of the whole system comes in handy. ;)
Jim, you are to be commended for posting this opportunity for us all to learn from. Your tackling of the electronics is not for the feint of heart.
"My point was & is that there is no substitute for understanding the whole system. One can not simply rely on one tool to fix everything. One cannot trust all parts in the system to be correct - but that is where we must start & where total understanding of the whole system comes in handy. Wink "
Words to live by, my friend!
Brian
What a journey, and we all learned something along the way!
The hobby, and I, thank you, Jim!
happy coaching!
buswarrior
Epilogue:
When I last posted, it looked like the low boost pressure problem was solved by switching the replacement engine ECM back on the engine. The issue was incompatibility of the boost pressure sensor with my original engine ECM. Subsequent testing has proven that the switch in ECMs has solved the problem.
I had mentioned that I was reluctant to use the replacement engine ECM because of compatibility problems with the bus and transmission parameters. That concern proved to be founded. I was not able to pick up speed, because the AutoShift supplies the speed signal via the J1939 connection and the ECM options were only tail shaft and wheel sensors. I used the ProLink to list all of the settings for the two ECMs, and found the two settings that needed to be changed. Problem was that the ProLink could not change the options, as they were not a part of the ECM software options. I ended up removing the ECM and taking it to Stewart Stevenson. They were nice enough to reprogram the ECM free of charge (5 minutes connecting and two minutes of programming since I knew what needed to be changed).
Today I took it on my big test run. I drove it down to Denver to fuel up. That is a 70 mile round trip. On the way home, the elevation changes almost 3000 feet (~~8200 feet max) in about 10 miles with some very steep climbs. That really maxes out the engine in several places.
The bus ran fine and the highest boost I saw was 27.4. Lots of power. Had to back off in a couple of places because of the charge air cooler/inlet air temperature got higher that I wanted (fan issues that I have the parts to resolve and mister not hooked up).
Thanks to all of you for giving me both information and support!!!!
Jim
Jim.
i am thrilled you got the boosere problem solved look to see you at a future rally or two.
I know the radiator mister is used by many, but if the Radiator/fan and piping is in good shape should there be a need for additional water?
John
John, my radiator does a great job. The issue the the charge air cooler which I had to install on the other side. I now use four pretty good electric fans, but I will be switching to a two speed hydraulic fan with one large blade. I have the air ducted down so that the fans are not fighting the big radiator fan.
I forgot to say that we will be heading to Albuquerque next week for the FMCA Rally IN THE BUS!!!!
We hope to make a few bus rallies this year as well.
Jim