Engine stalls at Slow Speed when Hitting Bump

[Colorado Scott]

1994 RRC 4.6L w/229 cam

It?s happened a few times at low speed (5-10 mph) only while breaking and turning left into my driveway (road to curb bump). When it stalls it just cuts right off with no stumble. It has been fine at highway speed so far but I feel it?s only a matter of time before it stalls on I-70 going up Vail Pass.

When it stalls I can shift to neutral and it will start right up. With the truck running at idle I have poked, prodded, tapped and giggled everything under the hood and under the dash and it will stay running. I replaced the ignition switch last year with a new one and it is still working perfectly. I checked the single wire connection coming from the dizzy to the coil- it feels loose but won?t lose connection and stall unless I pull it apart. I cleaned it up anyway. I also bumped up the idle a little.

Any ideas?

I'm thinking ignition but I?m moving to the fuel pump relays under the passenger seat next.

 

[carlosz]

loose relay or fuse carrier, maybe the ecu or fuel pump relays are just laying on the floor board and the jerking causes the points to loose contact momentarely just enough to shut down and reset as you restart.

 

[singingcamel]

Check your coil wire!

 

[Colorado Scott]

I'll have a chance this afternoon to check out the relays.

The coil wire was the first thing I checked! Coil and plugs wires were new when installed about 2 years ago when I installed the 4.6. They have about 12K miles on them now.

I'll report back later.

 

[singingcamel]

Is you coil mounted horizonal or verticle?

 

[Colorado Scott]

Relays check out okay.

The coil is mounted horizontally and appears to be original to the truck. Have an idea? I thought about an MSD replacement when I did the engine but never got around to looking into it.

 

[92rrrandall]

If your coil is nearly 20 years old then the oil inside of it may have started to leak out. This is a problem more so with cheap one size fits all store bought coils. The original Lucas or Bosch coil is correctly matched to the other ignition components.

After the oil has started leaking out then you the engine shut off when making slow 90degree turns or at steep angles like you only see when off road. The only way to check this is try another coil.

Randall

 

[singingcamel]

Change coil, I had a rr with issues when turning and it happened to be the coil..heed 92rrandall on he's note..

 

[Colorado Scott]

If your coil is nearly 20 years old then the oil inside of it may have started to leak out. This is a problem more so with cheap one size fits all store bought coils. The original Lucas or Bosch coil is correctly matched to the other ignition components.
Randall

No sign of oil leaking out but I did clean the entire engine bay when I did the engine swap. I'm considering getting a MSD Blaster as a replacement.

Thanks!