Power Loss after Idle

[roverdevin]

Hi everyone,

Just looking for some ideas on a power problem thats recently popped up...

My 2.25 LR has been running well all summer, but in the last week or so, it has developed a power/misfire problem after a prolongued idle or low rpm, such as slow traffic or long stops. When pulling away, the engine hesitates, sputters, and even backfires, before eventually sorting itself out. There is a fair puff of black smoke when first stepping on the gas after an idle. Is this an indication of an overly rich idle mixture or stuck choke cable? Choke seems ok, but the symptoms are similar to those when I forget to un-choke it.

Any ideas wouild be appreciated before I start fiddlin' with carb adjustments.

Devin Biln

[rick.m]

what carb are you running?? a weber?? rick.m

[roverdevin]

Yes, I am running the Weber.

[rick.m]

i had a similar situation. i blew out the 5idle jet. it is the large screw on the engine side . it has an o ring . also check if it is a 65. if it isnt it should be. dont you have aturner head?/ i also lifted off the top half of the carb and blew out the air mix jet. it is under a screw below the float. it was partially pluged. i had to get a new idle jet at overseas auto parts on 4th in van. 604-879-6288. it runs awsome since . the loher change i made was to get rid of the last piece of orriginal gas line and now have 5/16th through out. i had the truck on the flat up to 70miles per hr. on sunday. never had enough gas to get to that before. hope some of this will help. rick.m

[roverdevin]

Thanks, Rick.

I have always suspected that damned idle jet, as I know it tend to work los every few months. I think I will give your suggestions a try, as I have a gut feeling this it almost certainly a carb issue.

Devin

[roverdevin]

Rick,

My weber idle jet is a #50...not a 65 as you suggest I should have. Is it worth picking up a new one? Are there any other jets that typically need renewal whil I'm at overseas?

Devin

[ANDYD]

Hi Devin,
I had the same problem as you describe, so I fiddled with the Webber for weeks with no improvement...
What it finally turned out to be was a bad distributor cap & rotary arm. This was causing a weak spark, flooding when idling (seemed to push it through fine when running at faster speeds) then the unburnt fuel would burn & backfire in the exhaust system.
So if you have no luck with the Webber, take a look at the distributor,
Good luck!
cheers,
Andy

[roverdevin]

hmmm, it has been a few years since i change the cap and rotor. Thanks for the tip...I'll change those with my oil next week.

Devin