2008 fe350 backfire

[Monterey]

So I've been working out the bugs in my new-to-me 2008 CC with a fe350. The last thing remaining is the backfire that occurs once in awhile. Here's the situation:

• Drives just fine. Accelerates and stops smoothly. Runs a bit cold and I need to use the choke button now and then the first 30 seconds.
  
• When I come up to a stop sign and the motor almost dies and when I press on the gas to go again is when it will sometimes backfire.
  
• I've adjusted the idle stop screw without any noticeable effect.

So I'm wondering if any of these could be the problem:

• The spring isn't completely shutting the throttle plate when I let off the gas, allowing the backfire.
• Valves not adjusted properly, allowing unburnt fuel to get back into the intake or exhaust which then is ignited when the engine starts again.

Any suggestions? Thank you!

[mdillonaire]

Check your valves, I just rebuilt my fe350 and found that the intake was sticking open and the rocker pad was almost worn through. There is no adjustment for the fe350 as you have hydraulic lash adjusters but you can check out your rocker pad and also push the valve open by hand and see if its sticking. Mine was doing the same thing as yours and had a decent amount of buildup on the valvestem that kept it from completely closing. Also try a compression test.

[Tanman2015]

Could be in the timing off

[lockman1]

I'm curious Monterey... Is the backfire a "Poof", or a "Bang"?

My FE350 exhaust "poof's" when when I let off of the gas, still rolling, and restarted right away, and has since I've bought the cart new,
I write it off to excess fuel in the combustion chamber because of the engine kill circuit is engaged, then disengaged so quickly.

[Golf cart guy]

Originally Posted by Tanman2015

Could be in the timing off

Its not timing

[Monterey]

Originally Posted by lockman1

I'm curious Monterey... Is the backfire a "Poof", or a "Bang"?

My FE350 exhaust "poof's" when when I let off of the gas, still rolling, and restarted right away, and has since I've bought the cart new,
I write it off to excess fuel in the combustion chamber because of the engine kill circuit is engaged, then disengaged so quickly.

Oh, this is a "BANG" for sure. If anyone is around, heads turn!

[lockman1]

Originally Posted by Monterey

Oh, this is a "BANG" for sure. If anyone is around, heads turn!

I hate it when that happens!

I don't know very much about Precedents, or their cable adjustments to get the butterfly to completely close,
so I'll have to bow out of this one... good luck!

[mdillonaire]

Like i said earlier, check your valves. Pull the valve cover and see if theyre loose. the fe350 has hydraulic lifters so there shouldnt be any play in them. If there is, your valve is most likely getting stuck. Even if theyre tight, id still pull the rockers and check the seats to check for excessive wear. Thats a tell tale sign the valve is getting stuck and slamming against the rocker when the compression stroke forces it closed.

[Predataber]

Originally Posted by mdillonaire

Like i said earlier, check your valves. Pull the valve cover and see if theyre loose. the fe350 has hydraulic lifters so there shouldnt be any play in them. If there is, your valve is most likely getting stuck. Even if theyre tight, id still pull the rockers and check the seats to check for excessive wear. Thats a tell tale sign the valve is getting stuck and slamming against the rocker when the compression stroke forces it closed.

I had and have the same issue. I found that there was a hair of play and adjusted them ever so slightly and it worked well for about 20 minutes. I was getting "BANGS" and Sneeze type backfires on the regular. So now, when I'm in a busy area, I need to never truly let off the gas OR come to a complete store to squelch my embarrassment. do I just replace the lifters or should I confirm this is the issue? I use the cart pretty regularly and I would like to get this resolved.
2011 Precedent FE350.

[CP241]

FE350 have automatically adjusting valves. HLA failures are possible, but uncommon unless it's been pretty badly neglected on oil changes.

99% of the time if it backfires when you come to a stop like you describe, the throttle is simply not closing all the way. If its adjusted as much as it will go, the cable between the carb and the governor may be sticking and need to be replaced.

It may help solve your choke issue as.well. I have a 2002 carryall with fe350 and the cable was bad, frayed on the end. It still drove fine but I'd have to choke it on a cold start and it would occasionally backfire like.yours when I stopped at the mailbox. I replaced the cable and not only did it solve the backfiring, but I havent touched the choke handle once since I replaced it.