Help with check engine light

Sunbear · 10-13-2016, 12:43 PM

So I have a 5.9 cummins 12 valve mechanical motor in a 97 bluebird. Had a cracked head replaced it. No water leaks no oil in the coolant . When we fired her up today she had trouble at first then she smoothed out but the check engine light was on and it was beeping. Any thoughts?

cadillackid · 10-13-2016, 01:13 PM

sometimes under the dash where the diagnostic connector is, theres a "diagnostic button"..

turn on the key but without the engine running, and press that button.. the check engine light will flash out sequences which are the error codes.. might be able to match the codes up to a sensor..

my guess is likely just a wire or something didnt get plugged back in tight.. make sure the engine ground is good.. should be a large strap screwed into the block and maybe the head, which goes to the frame.. if that isnt making good contact, sensors can wig out..
-Christopher

Sunbear · 10-13-2016, 04:27 PM

Cadillac kid heres an update. I just moved her out of the field because of the pouring rain and she started right up and sounded good until ipushed the gas pedal then she bogged a little and had no power ,almost felt like all 6 tires were flat

cadillackid · 10-13-2016, 04:49 PM

almost makes me wonder if the HPOP pressure is low causing the injectors to not be able to fire... or is it air brakes and you tried to move it befpre the brake pressure came up?

or was it just bogging because its a heavy vehicle in a wet field trying to get onto the pavement with an auto trans?

-Christopher

Sunbear · 10-13-2016, 05:09 PM

It was weird because the thing wanted to fly in reverse but as soon as I put her in drive it just had no power.

Sunbear · 10-13-2016, 05:30 PM

Could a vacuum leak cause the sympton of having no power in drive? Could the new 800 head be faulty?

cadillackid · 10-13-2016, 06:03 PM

have you checked to make sure all 6 cylinders are firing? the HEUI rail getting air in it is a known issue of causing injectors not to inject fuel...

when you say bogs down.. are your RPMS low even when you are floored? or do the rpms go up and the bus just doesn want to move?

-Christopher

Carytowncat · 10-13-2016, 06:28 PM

Yeah power in reverse but not forward points towards the transmission...or brakes. My GMC will back up normal but barely move if i forget the emergency brake.

Good luck!

Sunbear · 10-13-2016, 09:29 PM

We figured out the "power" in reverse "no power" forward was that we were rolling back down a hill, but going up hill forward. Not a huge incline, but enough to make the difference.

Sunbear · 10-13-2016, 09:56 PM

So my bro who is doing the work thinks it may be when he replaced the tappet cover gasket and put the injection pump on something with the timing he is going to look into it tomorrow. Any new thoughts

Booyah45828 · 10-17-2016, 08:58 AM

Having you tried driving it with the trans in manual low? Being that it is a 12v, you don't have a computer triggering the check engine light. So odds are you have a low coolant sensor or oil psi sensor unplugged.

12v cummins isn't a heui engine. Should have either a p7100 or possibly a ve44. Both are mechanical injection.

Vacuum leak wouldn't cause power loss. If timing was off you wouldn't have power in either direction. How much of a hill are you on?

If all the engine stuff was done right, I'm leaning towards a trans or brake issue. Shift it into manual low (position labeled 1 on gear indicator) and see what you have. Also check trans fluid because that being low can keep the trans from acting right.

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