Any suggestions reguarding the following, 93 3/4 ton, auto just hit 100k miles. second pump done 1k ago,rotary type, came apart internally and destroyed the case.Done by local reputible injection shop, runs great, did some internal upgrades, 20+mpg. Occasionally after shutting down it will not restart. cranks over, puffs black smoke, does not even attempt to fire, like fuel is shut off, bad fuel solenoid??.All connections on wires are good. then after any where from a few minutes to an hour it will start normally. although it feels a little weak on inital rpms at idle. Pump is warrantied for 100k but I dont feel like waiting another 2 weeks to get it back like last time. are there any temp sensors on this year, seems to do it only after driven for a while, always starts when cold.

 

I experienced a similar problem with my 93 for a short time. Some how I was getting air in the lines to the injectors. Bleed a couple of the injectors and poof, It started right up! The problem just went away by it's self???? <br>Also, check the connector to the fuel solenoid. The connector can get loose or corroded and cause intermittent connection.

 

seems like if you see black smoke it must be getting fuel, but the only thing I can think of now is to hook a test lite up to the fuel solenoid lead and see if you have voltage there when cranking

 

Thanks for the replies!! Im new here but ive been dieseling for a while. When I compare it to my 85 K20/ 350cu at 7mpg with my camper how can you not own a CTD. I didnt think it was physically possible to cram that much fuel through a couple of main jets in a quadrajet. Im now packin a test light to check for voltage to the fuel shut off solenoid when it wont fire and a open end to bleed an injector to verify fuel flow. Im going on a trip this weekend and dread the thought of being possibly towed with the camper on it,if that is possible, to the nearest town for bosch warranty work if the pump goes south again. <br> ILL BE BACK. hopefully??

 

I had a shut-off solenoid go bad on my rebuilt pump 2 days after I put the pump back in. If it won't start but cranks over fine, being a Diesel, it isn't getting fuel. Turn the key on and unplug the hot wire at the top of the solenoid and touch it back to the connector. You should hear it click open if it's working. They are not very tight in the pump itself, and if you are stranded, with a little fanaguling you can take it out, remove the spring and plunger. Put the solenoid back in and drive it. Use the manual shut off lever to kill it if it's an automatic. I went right back to the pump place and they gave me a new one. Said it doesn't happen very often and in 17 years of working on Diesel VWs I'd never seen one go bad either!! Remember, cleanliness is EXTREMELY important in doing this. Good Luck on your trip ;D Jim

 

I'm afraid I may have gotten ahead of myself in the last post!! You do have an automatic, and maybe getting the solenoid out is impossible cuz of the linkage stuff, I don't know. Anyhow, please forgive me if it turns out to be more of a PITA than it's worth!! This comes from a guy who spent 2 hours on a charging problem because he forgot to check the fuse ??? ??? (Toyota Forklift) Jim

 

I think its time to cancel the trip. Its gotten bad enough Im afraid to get stranded. Yes it has 12vs to the fuel shut off, and even when it starts I cant feel a click on the solenoid at all. It has fuel to the injectors, I bled them,I had my other crank on it while I watched and there was way to much black smoke comming out the exhaust, a couple of times it blubbered and puked out more black smoke. Is it possible the pump internally has gone bad and dumping to much fuel on start up??, it runs great when its gets going, but it was just rebuilt1500k ago. I have never torn into one but it acts like its being drown in fuel on start up. Any quick replies will be greatly appricated. Thank You!!

 

One last thought, if the engine turns over too slowly the fuel won't ignite causing a lot of smoke when it does start. Does the engine seem to be turning at a normal speed?

 

That's a good point. I just looked at the pump diagram and when starting, the starting quantity equals 'maximum delivery quantity' until the rpm increases to where the flyweights pull the collar back to allow 'idle quantity'. I wish we could all get together and help you get on the road. The only other thing I can think of besides the pump is low compression, and the large amount of fuel being injected is &quot;putting out the fire&quot; so to speak. ??? Jim

 

If you have black smoke you definitly have fuel. No fuel no smoke, I think you might have either a timing problem, could be internal with the pump or your injectors are weak, dirty ect. It almost sounds like the injectors are dribbling in the fuel instead of spraying. That will cause this sort of simpton, but the fact that it runs fine other wise????? I wonder if you need to advance your timing? I would advance my timing and if that didnt get it I would take it back. Hope this helps you out a little. [undecided]

 

Well We got balsy and went for our fishing trip,Took the camper off case we had to be flatbedded, Is that a word?. In the process of running errans and taking the camper off it was unstartable about 50% of the time, 5 times or so in 3 hours?? The trip was 500 miles, granted I avoided shut down when possible but the problem did not occur one time.We ran 20+ mpg ,I shouldent say, but we hit 95+ MPH easy on I-5 ,and there was more to go. Hot or cold it fired right up. in reguards to cranking speed it turns over normal well say. It always fires up with a slight turn of the key, be it 110 or 18 degrees here. I also visited another diesel shop and there as were baffeled as everybody else is. the logic of the fuel quantity at full tilt on startup makes sense, and man was there black smoke the other day when it was really bad. Im convinced its gotta be internally in the pump. there were ZERO problems until the pump was installed. I hope the rebuilder will see this the way I do. Keep you posted. Thanks again for the info and help.

 

Running retarded timing will give you bluish grey smoke. If you are getting black smoke, I do NOT think it is a timing problem. I would try running some injector cleaner through the system, but I think it is a cranking speed or maybe compression problem, more likely a cranking speed problem.<br><br>You aren't getting any knocking, are you?

 

knockin, I dont hear no stinking knocking. Seriously, no. as I mentioned you can experiance the no start problem and 1 minute later try again and it will fire at the touch of the key. I talked with another pump rebuilder and was told of a cold start soleniod on the side of the pump nearest the fender. there are a couple of configurations, #1 by input of a temp sensor it will get voltage to richen,then warm no voltage to shut off. #2 it will get no voltage till warm then charged to close. Mine is similar to the fuel shut down solenoid. as he explained this it seemed very similar to my delima. however I dont know which one I have nor do I know if this is accurate info????? Sound familiar to anybody. Hey any body get gains from a K+N filter? Im very leary due to the failure of one on my NEW XR600 years ago ,it destroyed the motor as half the sand at Pismo dunes unknowingly ran thru the top end. HIPO yes,more air? sure just remove the element all togeather if you want flow, Heavy Duty????????, If you can see light thru the spaces in the guaze element than dirt will pass in my it would seem especially when they claim the dirtier it gets the better it works. Is the dirt and oil filtering the particules now??Such the pesimist EHHH. Cant beat WIX or Fleet guard it seems. to pricy to play games with bad filteration.

 

Sounds like the KSB solenoid- bottom forward side of the pump. It has a wire going to it. It's function is to advance the timing during start up. Easy to check, during a period where your truck feels good and is running, disconnect the wire. You should hear no difference. Now connect a jumper from the + side of the battery to it- you should hear an increase in engine rattle if it's working. I think KSB is German for &quot;Der Advancer of Zee Timing&quot; or something like that Jim

 

Im near packin wood thinkin were gettin closer to fixin this problem. Its to late to go look but im sure there are only the two items with wires to them. the first is the fuel shut off, top inner by injector lines out, by the way mine has 2 wires to it, anybody know why???, and the second is the item which Jim mentions, which is towards the bottom front section. Is this the KSB solenoid?? tnis is what was explained as the cold start fuel enrichner soleniod. or something to that effect. That sure is sounding like this is the culprit.