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wx8sky

1992 Ch612/em7-300 No Start

9 posts in this topic

Just found the site searching for manuals on this engine (no luck)...so I figured I'd try a post here.

I have a 1992 CH612 with an EM7-300 engine. It was out on the road one day running fine, and all of the sudden it quit running...no warnings whatsoever. Got it back into the shop to check it out and here is the scenario so far:

Fires on ether, but not with diesel

Checked the pickup tube from tank - A-OK

Cracked 2 of the injector lines loose and cranked it, no fuel

Checked the fuel shut off solenoid, seems to be operating properly...even tried to eliminate the plunger/spring and run without it - still no fuel pumping

Tried replacing engine position sensor, no luck

Called a few people, one place says it could be electronic (fuel pedal module or fuel transfer pump) - another shop says it could be the fuel injection pump itself.

Is there any place that I can find an actual troubleshooting manual or service manual for this year truck with a troubleshooting guide and component location guide in it? I tried mack direct, but wound up with an overhaul manual that did absolutely no good.

Any suggestions/input on this hair removal engine, would be greatly appreciated!

Don

Cleveland, OH

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Build yourself a small tank with either air presure or an electric pump to deliver fuel. Hook it directly to the injection pump and get the engine running. Then you can start looking for why your not getting fuel through the system.

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Just found the site searching for manuals on this engine (no luck)...so I figured I'd try a post here.

I have a 1992 CH612 with an EM7-300 engine. It was out on the road one day running fine, and all of the sudden it quit running...no warnings whatsoever. Got it back into the shop to check it out and here is the scenario so far:

Fires on ether, but not with diesel

Checked the pickup tube from tank - A-OK

Cracked 2 of the injector lines loose and cranked it, no fuel

Checked the fuel shut off solenoid, seems to be operating properly...even tried to eliminate the plunger/spring and run without it - still no fuel pumping

Tried replacing engine position sensor, no luck

Called a few people, one place says it could be electronic (fuel pedal module or fuel transfer pump) - another shop says it could be the fuel injection pump itself.

Is there any place that I can find an actual troubleshooting manual or service manual for this year truck with a troubleshooting guide and component location guide in it? I tried mack direct, but wound up with an overhaul manual that did absolutely no good.

Any suggestions/input on this hair removal engine, would be greatly appreciated!

Don

Cleveland, OH

Don is there a valve on the front of the fuel pump with a wire going to it?if so remove the guts of that valve and reasemble!? question two do any of the accesorys work heater fan ect when the key is turned on does the check engine light come on then go out! if not you have a bad acssory relay in the dash under the cup holder 4 screws and your on top of it.If you don't her a clunk in the dash when the key is turned on its likly the relay even if you do it can still be the relay check it has power coming out when the key is on ,the heater fan should run if its ok.

Check this stuff and get back.

Fred

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Don is there a valve on the front of the fuel pump with a wire going to it?if so remove the guts of that valve and reasemble!? question two do any of the accesorys work heater fan ect when the key is turned on does the check engine light come on then go out! if not you have a bad acssory relay in the dash under the cup holder 4 screws and your on top of it.If you don't her a clunk in the dash when the key is turned on its likly the relay even if you do it can still be the relay check it has power coming out when the key is on ,the heater fan should run if its ok.

Check this stuff and get back.

Fred

Good Morning Fred,

Yes, the accy relay is working. I did remove the "guts" from the shut off solenoid at the front of the pump, still no success.

Someone that I spoke with yesterday, made mention of the fuel transfer pump and said it was seperate from the fuel injection pump...and that may have failed, that's why I was hunting for a manual with a component locator in it ;)

Don

Edited by wx8sky

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Good Morning Fred,

Yes, the accy relay is working. I did remove the "guts" from the shut off solenoid at the front of the pump, still no success.

Someone that I spoke with yesterday, made mention of the fuel transfer pump and said it was seperate from the fuel injection pump...and that may have failed, that's why I was hunting for a manual with a component locator in it ;)

Don

It sounds electrical to me if it just up and quit with out sputtering!If it sputtered to a stop you will likly be looking at a transfer pump.

mounted on the side off the fuel pump . remove the round plug going to the fuel pump and look at the the plug itmay need new pins does any of the holes look to be brown from geting warm.Also there is a ground faultbreaker on the fire wall black rectangular box 2x three in size jump across that make sure it hasent failed.

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It sounds electrical to me if it just up and quit with out sputtering!If it sputtered to a stop you will likly be looking at a transfer pump.

mounted on the side off the fuel pump . remove the round plug going to the fuel pump and look at the the plug itmay need new pins does any of the holes look to be brown from geting warm.Also there is a ground faultbreaker on the fire wall black rectangular box 2x three in size jump across that make sure it hasent failed.

Don did you nail this down.Please post your fix so others can benifit.

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Don did you nail this down.Please post your fix so others can benifit.

Sorry about that, got tied up with a wheel seal/brakes and tires yesterday.

I checked the harness plug, all pins look brand new, no burning or yellowing at all. As far as the fuel transfer pump, is that at the side of the fuel injection pump (looking at pump/lower right side)? I also checked the ground interrupt on the firewall, that seems to be working with key on (has continuity through).

Normally this high tech stuff (low tech co. garage), we usually send it out...but have some time on our hands to try and save us a little $$ in the long run :D

I am going to snap some pictures today, maybe someone can help identify component locations, etc.

---Photos---

eng1.jpg

eng2.jpg

eng3.jpg

eng4.jpg

eng5.jpg

eng6.jpg

Edited by wx8sky

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Sorry about that, got tied up with a wheel seal/brakes and tires yesterday.

I checked the harness plug, all pins look brand new, no burning or yellowing at all. As far as the fuel transfer pump, is that at the side of the fuel injection pump (looking at pump/lower right side)? I also checked the ground interrupt on the firewall, that seems to be working with key on (has continuity through).

Normally this high tech stuff (low tech co. garage), we usually send it out...but have some time on our hands to try and save us a little $$ in the long run :D

I am going to snap some pictures today, maybe someone can help identify component locations, etc.

---Photos---

eng1.jpg

eng2.jpg

eng3.jpg

eng4.jpg

eng5.jpg

eng6.jpg

Hey Fred,

Could you offer an idea of where the fuel transfer pump is?

Don

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Hey Fred,

Could you offer an idea of where the fuel transfer pump is?

Don

Second to last pic!

Remove the fuel line from the injection pump elab valve and crank it with the line off in a pail its likly not the pump but if its working it will show ya.

your positive you gutted that elab valve ????? take the wire off and tape it up!

When you turn the key on you should hear a faint click in the rear of the fuel pump if your like me and cant hear get someone with good ears to listen.

Check the ecu fuse or breaker for power.

Also Don right around or below the washer bottle the there is a rectangle plug that goes to the fire wall have seen that plug get wet inside look for the green stuff in there!

Ya need a 1/4 or 3/16 inch socket to take the plug out!

Also temporaraly jump over that ground fault on the fire wall just incase

One mor thing i thought of is there is a diode in the fues panel far right that can cause greif some times. it looks diffrent than everything else in there.

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