Im having this problem with my rig cutting out while the motor has a load on it but only in reverse. It never dies but misses badly. I cant figure it out. Has anyone else had this problem? Any ideas? I looked for any wires that might be getting pulled but found nothing. Its been doing it for about 3 months now. I thought mabey it would get worse and become more obvious but no such luck. I think its time to get this fixed.

Mike

Sounds strange, it would have to be something
with the torque and the engine movement, but
I have never heard of this problem.

You might look under the vehicle for some other
loose wires or tight lines, check the fuel pump
wires for grounding and lines being kinked, I
don't know how rev could affect these, just tossing
out some ideas.

Good Luck
Darrin

I had same problem but then it would do it periodically in forward too, especially 1st gear. I ended up finding the distributor pickup wires at the plug were frayed and broken. This caused the engine to run fine but as soon as you torqued it up it would cut out. This was on an 87 sami which is similar to sidekick.
While it's running do a thorough wiggle test on the wires going into the distributor housing to see if that's your problem. (not spark plug wires)

how about mud in the backup light's?

Naw, it ain't mud in the backup lights.....its the direction he's been flying this rig.

The soloution is to try to keep it running in reverse and fly it that way.

But honestly, I wonder if there is some sort of short that is coming off the reverse light circuit that might be affecting the PCM?   Just a guess.

In 89's the wireing runs:
1-from under the dash into the door railing on the floor(where you step when you get in)
2-through the railing / rocker panel to inside the wall behind you rear speakers
3- over the rear wheel well to the back

in the railing (2) is proned to filling with mud and water, trashing the wireing and/or shorting them out. I had to replace some of mine due to mud. And just last weekend I noticed I was dragging something down the road and the rocker had rusted through and a caroded wire had fallen out

If you pull the drivers side rear interior panel and speaker you can see if there is alot of stuff in it. If so there is a good chance of a short.

Zig

I had pulled the wires out of the sencer on top of the tranny before.  my backup lights stoped working but it never cut out.  lata stu

I'd suggest finding something tall enough and hook a com-a-long up to it , the engine mount and slowly pull the engine over to one side (the direction of torque while in reverse) and see if you can't duplicate the problem while standing still.

If you can get the problem to occur then just start checking it out.

Note:  The only time I have trouble at an idle was when I had EGR troubles (sticking open).  Just a thought.

Im going to putz with it tonight. I have already tried to duplicate it by wigleing wires and moving the motor with no luck. I never thought to unhook the back up light switch at the trans. I dont see how that could make it cut out but I will give it a try. Thanks for the Ideas.

Mike

I figured it out. The plug wire was cracked near the distributer. When in a hard reverse situation the spark would jump to the steel vacuum line for the brake booster.  

Mike

Glad to here you gotit. Similiar to the problem I had.

Now how did that plug wire crack I wonder?/  

After closer inspection I realized with the torque of the motor in reverse the clamp for the hose was cutting the wire. I rotated the clamp.

Mike

Ahhhhhhhh now I begin to see the problem here........

Wonder why soooooo much torque was applied to the motor?  

methinks this has something to do with getting a running start to..............fly?  Perhaps?