Engine stalls when throttle is cracked wide open

[ItchyRichy]

Hey Everyone! I'm stumped on my current problem with my 86 GWag 360. Here's the problem: when the engine is running either fully warmed up or cold (it happens more often when it's cold), I can kill the engine by cracking the throttle wide open. The engine doesn't sputter or cough, it simply and quietly shuts off. I've rebuilt the carb, installed a new fuel pump & filter, installed the TFI ignition, and just this weekend replaced the seized EGR valve with the anti-knock kit EGR valve. My timing is currently set to 6 degrees of advance and I'm going to start increasing that now that the EGR valve is functioning. Any other ideas?

[jasonthomasfrance]

Happens to me to. But if you accelerate slower, it doesn't, right? Only when the throttle is mashed? Sometimes it recovers for me, instead of shutting off...

[ItchyRichy]

Yep. That's exactly what it does. Roll on the throttle slowly and the beast pulls away. Crack the throttle open and it's like you shut the key off.

[ChrisCollege]

Same problem here. It thought it was a carb issue but I have rebuild the carb twice. I also have done all the TFI ugrades and have the timing set at stock. I guess it could be my loose timing chain. Any one know if a loose timing chain could cause this condition?

[Bob Barry]

Sometimes the accelerator-pump lever on the throttle-shaft of the 2150 carb gets gummed up and sticks, even if it's been dipped in carb-cleaner as part of a rebuild. You can test this by cracking the throttle open with the engine off; if the accelerator pump lever doesn't move immediately with the throttle-lever, then it's probably sticking, which can cause acceleration/full-throttle-stalling problems (BTDT).

The solution is to spray some penetrating oil between the accelerator-pump lever sleeve and the shaft it rides on, then spray it with brake-cleaner to get out any gunk, then spray it with some lubricant so that it moves freely.

[wagdriver]

I'll have to agree with Dr. Bob on this. If the accelerator pump is not functioning properly it will cause this problem. When you open the throttle, if the accelerator pump does not instantly dump some gas into the intake the engine literaly runs out of gas for the moment and dies. Dr. Bobs advice is good and you will probably solve your problem. Also I think you timimg is late from the specs I find it should be up around 12 degrees BTDC +/-2 degrees @600rpm in drive wheels blocked.

[Puslinch]

EGR valve will do the same thing, it'll kill an engine right way if it opens to quickly.

gb

[ElkHunter]

One other possibility is the choke unloader.

This usually doesn't make it die, but does make it run like $%#&.

ElkHunter

[ChrisCollege]

Thanks for the suggestions. In my case which may be diffrent from the others experienceing this problem, I have put in two accelorator pumps and checked their function. I am getting a good shot of gas although one side seems more misty than the other which has larger drops of gas shooting out. I also have put in a new power valve. As for the choke take off, mine is working well. My timing is set at 12-13. The EGR moves with some effort. Don't know how else to check the EGR. Any other advise would be greatly appreciated. I am at the point of trying a new carb unless someone has some good advice. One other piece of data. If the wagon is not warmed up well it may stall even when applying the gas pedel slowly. I am begining to think that stock idel settings may be to low with my stretched out timing chain. Any thought on the timing chain?

[ September 25, 2001: Message edited by: ChrisCollege ]

[ItchyRichy]

OK. I gave my accelerator pump actuator a good spraying of Liquid Wench, followed by brake cleaner, and finally some nice RemOil (I was cleaning my skeet gun after a few rounds this weekend and had the RemOil handy). My Wag no longer stalls instantly when I nail the throttle. Hot or cold. It bogs a bit, but doesn't stall. I'm going to up the timing to 12 degrees now that I have this problem solved and the new anti-knock EGR valve.
Looks like my only pre-winter task right now is fixing the manifold heater stove.
Thanks again!
RichG

[wagdriver]

CC in your case I would suspect a vacuum leak some where. Probably in the carb base area. Use some carb cleaner to spray around that area with the engine running and see if you notice any changes in engine speed, if there is a change you have found your problem. Once you fix the leak you probably have to reset the carb.