Workhorse 454 dies

[DedEye]

2000 Damon Daybreak on P32 with 454 engine. Cold, starts, runs fine for about 10 min.  Then cuts out on all 8 cyl momentarily, then fires all 8, then repeats several times, each getting shorter until it will bog down and stop.  Let cool and it will go again. Changed coil/ignition module on side, dist. cap and rotor, had fuel pressure when stopped, checked & cleaned EGR. No change with any.  HELP

[Mlw]

So as I understand the engine dies completely momentarily and fires up again. This sounds as a relay or ignition switch gone bad, not the ignition module or the parts that you've changed. If the problem would have been there you would have misfires, but the engine would stay running (rough).

I don't know if you have a wiring diagram but start with measuring the voltage to the ignition module and see what's happening when the engine starts dying. If the voltage drops out you're at the problem mentioned above.

Are you sure you have the right ignition coil? Has the engine worked well with the coil before? If you have the wrong one it can be it runs hot and causing the problems you are experiencing.

[DaveVA78Chieftain]

2000 Workhorse P30 was last year of 454 and was a OBD2 system. What are you getting for OBD2 codes when it shuts down?

[DedEye]

Thanks Mlw. I have seen the fuel pump relay come up several times and just now located them in the front of dog house (eng hatch)  Very difficult to get to and no labels so I don't know which is fuel pump relay.  I had not thought about ignition switch. Have no wiring diagram, so how to check voltage on ignition module.  Any more info would b e greatly appreciated.  A friend checked the codes with his fancy computer, and found no reported errors. But it still spits, sputters, and stops as soon as it warms up. Takes about 10-12 min when starting cold. Then each time gets shorter until it wont go at all.  Let it cool off, and we start again.  Thanks again for your help.

[DedEye]

DaveVA78Chieftain_____ Thanks for replying. No error codes are reported. Checked with a fancy Snap-On machine.  The obd computer says nothing is wrong? But, it wont run.  :-(

[RockwoodMike]

Sounds like an intermittent short to ground of a wire..check any and all harnesses for rat damage or chaffing of the harness against a rub point..a 5 volt reference circuit hitting the ground could cause the whole engine to die

[Mlw]

As we are on CWVRV I have the tendency to think too classic. a 2000 454 is something different than a 1979 454 because of different technology. FUel injection instead of a carburetor and ignition coils per cylinder so forget about my remarks of Ignition coil because there is one for every cylinder, They can't all go dead at once.

I think that Rockwood Mike has an excellent point. and check this first. Also check if the ground straps are free of corrosion and the connection points are clean. Disconnect them, give the connection point on the ground wire/strap and the connection point on the engine a good scrub with a wirebrush and clean with brake-cleaner and replace.

Then the question is, do you have a multimeter and more importantly do you know how to use it, A multimeter is pretty unmisable in trying to solve this kind of problems.

Now if you really understand what's told in the video, let me know and I can tell you how to find and solve any electrical problems in your RV, but if you don't I would just be putting up a lot of text for nothing, only making it more difficult.

I have seen the fuel pump relay come up several times and just now located them in the front of dog house (eng hatch)  Very difficult to get to and no labels so I don't know which is fuel pump relay.

With fuel injection there is a huge possibility that this is your problem. No power to the pump, no fuelpressure, no fuelpressure, no running engine.

There is a simple trick to find if a relay is bad, but be carefull not to burn yourself. If one of them do feel hot, you know something is wrong immediately. I would also check the wires connected to them because if the wires are hot too the problem lies further. Electricity is nothing more then logic and when you find that out and understand this electricity realy isn't difficult.

Now for measuring the ignition module you really need the wiring diagram because then you'll know which wire to trace, ore you really must know what you are doing. Maybe you can get a Chassis service manual somewhere. It's an unmissable tool when you want to work on your rig yourself.

[DedEye]

Thanks soooo much Mlw for your info.  I am quite proficient with multi meter and electronic servicing, but I am not familiar with the newer vehicles, especially where things are located, and what they are supposed to be.  I am already checking wire harnesses, multi plugs etc.  The problem is, except for obvious chafe, signs of hot, rodent damage, etc. I don't know just what I am checking.  This engine has a spider distributor (replaced) but only one coil and ignition module, (also replaced). I actually put the old coil back on when new did not cure. Made no difference.  Guess it was not bad. Now new one back on.  I am borrowing a fuel pressure test gage to double check.  I had pressure when engine stopped, but that may have been static on the last few compressions.  Should get that done tomorrow or next day or so.  I will try to check voltage at ignition module plug, but as of now, do not have any pin out diagrams, so don't know if the correct voltage is on the correct pins only.  I will also try feeling the relays (long reach in small place).  More info as I progress.  Again, thanks so much for your time and interest.  (I learned about cars with points and condenser, and a round distributor) 
AFTER THOUGHT: This problem first appeared while driving through a very heavy rain. Have looked at things, but just now making the possible real connection in timing of events.  Hope this helps.

[DaveVA78Chieftain]

Unfortunately you can no longer obtain the Workhorse P30 manuals for free. You now have to Purchase them and they are not cheap. Select Chassis year from that page to see the list of manuals.

[Eyez Open]

Proficient with a multimete is all that is really needed to diagnose efi. Well almost.. ok let's keep this 5volt simple meaning the eprom or computer sends out a 5 volt signal to all the sensors. Now take your meter and check those reference signals. If there nice and linear in there voltage readings there ok...if the readings spike and jump you have found your issue. Do not forget the knock sensors.

I will find some links to the processes..it is extremely basic stuff..efi is extremely simple, the programming extremely boring and repetitive...unless your writing the programming for the first time. That was done long ago.

Each sensor is tested as below

https://youtu.be/_skVHdgtMTU

https://youtu.be/_DB9I2nccAo

https://youtu.be/p0ocaDmcAIM

https://youtu.be/pWBsq0J9McI

[DaveVA78Chieftain]

1999-2003_Workhorse_454_Engine_Controls Schematic

Starting and Charging Schematic

[RockwoodMike]

If you look at page 5 of the 454 engine control schematic that Dave put up, you will see that 1 circuit powers all the injectors..You have connection 200 and 107 that feeds power to the 8 injectors..If a bad connection happens at those 2 points, instant shutdown of all injectors..

If that circuit was grounding, then the fuse would be blown..But a bad connection at C200 and or C107 and that would produce the symptoms you are stating..

[Mlw]

a bad connection at C200 and or C107 and that would produce the symptoms you are stating..

All I can say is: there you go! Exactly what I meant in my first post and glad to help. I'm learning on the way too and we are exactly in the same shoes as it goes about older vs. newer cars.

My Daily driver is a BMWE39. Not exactly a new car, but the amount of electronics, sensors and control modules in there is more then enough to get cold feed just looking at it. But as Germans overengineer everything and is the last BMW series build by mechanics instead of accountants everything still works perfect after 20 years, and let's just hope it stays that way.

With My RV, a 1979 Class C Dodge Minnie Winnie on a MB400 Chassis it's different altough I have to say that it's a Californian edition and I was suprised to find so many sensors and Bleep Bloops in a 40 year old vehicle.

As you say you're quite proficient with a multimeter I don't have to explain you how to check your wiring then. Saves a lot of text. As for measuring the modules, Eyes open beat me to that. He has a tendency to do that  All the better for you because I could not have done a better job.

Also Dave kicked in, so I guess you now will have plenty of info to go ahead. Good luck in finding your problem and let us know the outcome.

[Eyez Open]

If you look at page 5 of the 454 engine control schematic that Dave put up, you will see that 1 circuit powers all the injectors..You have connection 200 and 107 that feeds power to the 8 injectors..If a bad connection happens at those 2 points, instant shutdown of all injectors..

If that circuit was grounding, then the fuse would be blown..But a bad connection at C200 and or C107 and that would produce the symptoms you are stating..

Rental tool program AutoZone.

https://www.autozone.com/loan-a-tools/loaner-injector-signal-tester/p/oemtools-noid-light-set-injector-pulse-tester-8-piece/948078_0_0

[Oz]

I've used the rental tool program from Auto Zone several times.  It's a real wallet saver!

[kenwautoone]

Just a thought,you mentioned this started after rain storm.Check to see if this has a crank and cam sensor on front of engine.sometimes they don't set a code....If one is bad , replace both.Buy AC Delco replacement parts.Do not buy electronics from AutoZone/O'Reilly.

[DedEye]

HURRAY    FOUND IT.  A very special thanks to all the members who answered and offered help during this time.  The info was invaluable.  The trouble started with animal (dog)(probably chasing a rat) tearing some wires loose under engine.  Serviced at repair shop.  Someone connected the wires from the sensor together with Stacons, then tucked them up in the frame, virtually invisible.  Tug on any one and it would pull right out. (Quality service no doubt)  Re did all the connections with proper solder and insulation, and she runs like a charm.  This is a great place for help, and I thank all of you very, very much.

[DaveVA78Chieftain]

Congratulations!