Hi there, my name is Logan, I have an 86 g30 ambulance van with a 350 and I’m having this issue that keeps coming back where I lose power under load/while accelerating, almost like it’s stalling. Starts fine, idles fine.. I’ve replaced plugs, wires, distributor, fuel pump and filter.. no matter what, I drive a few hours and it’s happening again. My girlfriend and I travel/live in the van, so there’s a bit of urgency to fixing this issue, please help! Thanks in advance!

 

Is this a TBI engine or what? Make sure the injector works properly.

other ideas:
- catalytic restriction
- bad coil
- low cylinder compression

 

It’s got a carb, no injection.

As for catalytic restrictions, I don’t believe so.. an exhaust leak in front of the cats would lead me to believe that if there was any restrictions, the air would have other ways out.

We don’t have coil packs anywhere, just replaced distributor and what not though.

And if it does have low compression, then why would it work fine and only do this intermittently?

 

The engine must have some way to generate the high voltage needed to jump the spark gap

 

Computer controlled carb. The engine management on these is fairly simple and relies on some data to control a solenoid that adjusts the mixture. You'd have to check out the parts for any loose connections, dirt, or just plain failing parts. You can also check for codes if it's giving you a check engine light by jumper the A-B terminals on the diagnostic link (should be bottom of dash right of steering wheel) and turn key on and count the flashes (a 12 is normal).

Some people just remove this system and replace it with a regular carburetor, which also requires changing the distributor.

One other note, a lot of states it's not legal to run it lettered up and with the emergency lights intact, as a private vehicle.

 

Check for vacuum leaks. Look under the hood after dark for ignition arking. The flapper in the air cleaner might not be opening.