No idle, but runs at 1400+??

Squirt-Truck

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Well guys, I have had a friend come to me with a problem that is way beyond anything I have encountered. Search has not afforded any answers and the TM's have not even addressed the problem (symptoms).

He has an M39, something...he has just installed a remanufactured (AMBLAC?) injection pump and is trying to get engine to run. The engine ran like a top several months ago when he first started this project and felt the need to replace the pump among other items he is doing. (The truck is far from running at this time...) He is frustrated and ask for assistance.

My experience has been to bleed all the fuel points, spin the over to assure lubrication and give a short shot of starting fluid to get the injectors to bleed and up they start. NOT this old girl. We have spun her over so much that we are using Little Truck to slave the LDS. We can checked the timing several time and it is good. Fuel has been bled from all points. A good shot of starting fluid will get her to run and she is smooth as silk at 1400 to 1500, not wanting to go over that considering that he does not have any cooling system.

ISSUE, if the RPMs drop below 1100 they continue to slowly settle to 0. (Slowly being 5 seconds or so.) I have never encountered anything like this.

He does not have computer access so I am acting as and in-between. I will scream if Squirt acts like this when my remanufactured pump goes back on......

Open for any thoughts.
 

Squirt-Truck

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Just checked that, it seems to be properly functional.

He did get it down to 1000 RPM. What ever it is is improving, but painfully slowly....
 

gimpyrobb

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So this is a complete IP, not a HH swap? Just making sure the head isn't 180* out from the pump itself. Is this a reman pump? What is the date? Maybe it needs to "break in". I have yet to install a complete IP. I know the reman HH start right up, maybe the complete IP needs to be run for a bit? How long of run time has it had? Is there a start up procedure for a complete rebuilt motor?
 

Squirt-Truck

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Gimp, good questions. I have installed re-mans before and while being slow to bleed, generally start-up in a few minutes of crank time.

This was a complete re-man, has been on the shelf for a few weeks. It was supposedly bench run on an American Bosch set-up machine. No start-up procedure given by the company that did the work.

Have you ever gotten a head in 180 out? What does the engine do? I have confirmed that the timing pointers are correct and the grooved tooth (normally painted red) is one tooth past the other pointer.

There is not more than one grooved tooth is there????????? How can I confirm if the pump is timed properly, internally. (Short of opening my spare pump and putting it on his engine.)

I am game to re-time the pump with the crank 360 from where it is (180 on the HH) but I cannot afford to kill his engine, that is why I ask what happens if one is 180 out.

I appreciate the assistance.
 

derby

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I had this happen on two differant trucks of mine. One, the fuel cut off looked like it was all the way forward but was at about 6 oclock. Removed the shut off lever ,lubed and re-installed nice and loose no problems.
The other would run as you have described, lots of cranking, jam a gassed rag in the intake and would fire, then run wild almost to governor then slowly calm down and struggle to run goosing the throttle to keep 1K rpm. I replaced the head and it purrs like a (whisteling) kitten.
I don't know if it would run at all or very well if it were 180 out. If you pull the front valve cover and check that both intake and exhaust valves are closed when all your marks are aligned you should be good.
 

derby

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I also forgot to add that when I removed the head there was a small amount of diluded motor oil/diesel in the shut off area, so i assume the head was worn and leaking fuel by the plunger. There is also a guy in the classifieds that has a guarenteed good new/ or rebuilt pump for sale.:oops:
 
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AndrewH

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I have managed to install a replacement HH 180 out. The engine is very hard to start, will not run smoothly at low rpms, and will lose power until it stalls. It has virtually no pulling power. Mine would move the truck around (M35a2) but could not go up a slight grade in low/1st. But it would run. Once warn it would idle with the hand throttle set to 1000rpm or so. Kinda sounds like yours.
 

gimpyrobb

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I have managed to install a replacement HH 180 out. The engine is very hard to start, will not run smoothly at low rpms, and will lose power until it stalls. It has virtually no pulling power. Mine would move the truck around (M35a2) but could not go up a slight grade in low/1st. But it would run. Once warn it would idle with the hand throttle set to 1000rpm or so. Kinda sounds like yours.
Mark, this post is why I asked. If the HH is 180* out, you would line everything up according to the marks, pull the HH out, turn the motor one revolution and re-seat the HH.
I figured a rebuild would not have this issue, but we have seen many things with these trucks(MVs) not right. It is a PITA so I would rule out all other options first.
 

Squirt-Truck

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Gimp,
Headed that way this evening (I hope), will confirm timing starting from "Timing 101" with the #1 valves.
Sounds like what AndrewH, and you are headed the same way.
 

spicergear

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I got a '69 Corvette that way one time. Started running rough for the guy backfiring out of the carb, he had a guy look at it and told him the timing was 180* out and changed it. Ran...no power...guy disappeared. A couple years later, another guy looks at it and told him the timing was out...this continued several times. The guy was frustrated and put 111mi on the car in 10 years and put it up for sale. All that time the cam was bad with an exhaust lobed wiped off. I turned some good coin on that. ;)

Moral of the story; it's not the toughest thing to get something timed 180* out and chase your tail for a while.
 

Squirt-Truck

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Does not look like I will get to do the basic 101 checks this evening. I have no problem admitting when I have messed it up, but, good thing I have almost no hair or I would have pulled it out by now.......:|
 

Squirt-Truck

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Well, no DUH moment. The timing is right on and still no fire.
I have one more creative thing to try and then it is pull the pump back off and back to the shop.
FWIW, I did change the pump to 180 out and all it does is puff smoke.....

At this point I am open for wild and crazy thoughts........
 

gimpyrobb

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So he pulled the IP, took it to the shop, they supposedly "fixed" it, and now you have issues? I can understand 180 out, anything else I would let them handle. Did I miss anything?
 

gimpyrobb

dumpsterlandingfromorbit!
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This is where I get REALLY frustrated. I had a company Rebuild a radiator for me. When I got it installed, it leaked. I had to try real hard to not throw it at them when I took it back to be fixed. I wish you luck with this.
 
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