- Thread starter
- #21
will try this as well if fuel filter change doesn’t help. never done this before so I may follow up with a couple questions. thank you @charliemeyer007
Help - FJ40 is sputtering out and having trouble downshifting
- Thread starter Rigsby92
- Start date
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- Thread starter
- #22
some pictures attached. @Mark Jennings mind sharing what the carb float is and what to look for ? thank you - much appreciated
I think that Holley has a ‘stintered metal’ filter behind the fuel inlet fitting….is that clean?
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- #24
@Mark Jennings hard to tell. I think it’s naturally a dark color, but I could be wrong.
+1 I'd bet there is a fuel filter inside the housing under the HOLLY. Unscrew the fuel line, then the bigger fitting. Use carb spray to wash out the filter unit, old gas turns into varnish that will plug the filter, same as powdered rust from the tank - usually powdered metal crushed together.
Your air filter looks dry - I think they work better with filter "snot" oil. I have the big oiled foam unit from man-afre since about 1984 still there still works fine.
Your air filter looks dry - I think they work better with filter "snot" oil. I have the big oiled foam unit from man-afre since about 1984 still there still works fine.
You have to remove the fuel line, then the big hex fitting on the end of the carb is removed and there is a small filter in there.
The Air filter looks like a K&N, it has a cloth element. Clean it up with Carb Cleaner then let it dry in the sun, then use a bit of ATF to oil it up. I used to use a small squirt can with ATF around the top edge and let it ‘wick’ down….just remember ‘spareingly’…..
Skreddy
SILVER Star
The float adjustment is circled in blue below. The air fuel mix in red.
Before getting too deep into a possible carb problem, have you checked your timing and points gap (as mentioned). Have the valves been properly adjusted?
When the bogging occurs, what speed are you going, what rpm (realize you may not have an tach) and what gear? Reason being, if you’re trying to go up a hill say at 35 mph in 3rd gear, that’s your problem.
Get a good baseline, then start diagnosing potential problems. (Good filter, plugs, wires, cap, rotor, points, fresh fuel, proper valve adjustment, good condition vacuum hoses).
Before getting too deep into a possible carb problem, have you checked your timing and points gap (as mentioned). Have the valves been properly adjusted?
When the bogging occurs, what speed are you going, what rpm (realize you may not have an tach) and what gear? Reason being, if you’re trying to go up a hill say at 35 mph in 3rd gear, that’s your problem.
Get a good baseline, then start diagnosing potential problems. (Good filter, plugs, wires, cap, rotor, points, fresh fuel, proper valve adjustment, good condition vacuum hoses).
Skreddy
SILVER Star
Post up a good pic of the whole engine bay as well. Members here often spot small issues that can help someone who isn’t as familiar with what goes where or what should be there.
- Thread starter
- #30
OK, i have an update. first, huge thanks to @Mark Jennings, @pb4ugo, @FJmaine and @charliemeyer007 and everyone for the feedback. immensely helpful.
I replaced the fuel filter and I was surprised how much sludge was in the older one. see pictures. thanks for the advice on checking that.
after replacing it, I definitely noticed less sputtering at the start and the throttle felt strong again. i drove around my neighborhood and it drove fine (flat road). i went ahead and tackled a short, inclined hill and surprisingly no problem. keep in mind, it was a very short hill (30yds of incline). i went ahead and drove it to a longer, less steep hill, and boom, it sputtered and bogged down about 40 yards into incline (bummer).
one thing I wanted to mention for the group was I noticed smoke would come from beneath the center dash (picture included, i don’t know this part is called).
overall, it drove better — zero doubt. but it’s still losing some power on a modest, longer incline.
I replaced the fuel filter and I was surprised how much sludge was in the older one. see pictures. thanks for the advice on checking that.
after replacing it, I definitely noticed less sputtering at the start and the throttle felt strong again. i drove around my neighborhood and it drove fine (flat road). i went ahead and tackled a short, inclined hill and surprisingly no problem. keep in mind, it was a very short hill (30yds of incline). i went ahead and drove it to a longer, less steep hill, and boom, it sputtered and bogged down about 40 yards into incline (bummer).
one thing I wanted to mention for the group was I noticed smoke would come from beneath the center dash (picture included, i don’t know this part is called).
overall, it drove better — zero doubt. but it’s still losing some power on a modest, longer incline.
- Thread starter
- #31
Engine bay pics attached ! let me know if anything sticks out.
cc: @Mark Jennings @charliemeyer007
You need new battery terminals + is cracked. Make sure the wire is corrosion free before you connect it. I actually prefer cast on battery terminals as they resist corrosion much better. Thick ones like for diesels are way better for the amps to pull the starter when its cold. I run a ground wire to the frame and the other to a starter bolt. Get a few extra fuel filters now - there is likely stuff still in the tank. That paper element will not pass fuel if it gets wet with water - set it in the sun for a few days and it will dry out and work again. Put some gas drier in the tank now too - that will help
After looking at the picture of the fuel filter, I wonder how much gunk is in the fuel pump. May be worth it to pull the pump down and clean it and get a fuel filter upstream of the pump. There should be a soft line under the passenger seat, tank outlet.
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- #34
I’m beginning to think the same. I bet there’s a bunch of gunk in the fuel pump. will figure something. many thanks again
I had the same filter issues when I first got my 40 back on the road. I could drive about a mile with no problem, then it would bog down and sputter. If I pulled over and waited a couple of minutes I could go another mile. I found that the pick up line in the tank was getting clogged. My simple fix was to carry an air tank with me everywhere I went for the first couple of months and if I had the issue, I would pull the filter and blow a quick blast of air through the line back to the tank to dislodge the crud. After a few weeks and a couple of changed filters I stopped having issues.
Fast forward to this fall and I was on a trip in the woods and I think I knocked more crud loose and started running into the same issues. Changed the filters and ultimately ended up blowing air back into the tank and no more problems. I think I'll pull the tank this winter and properly clean it.
Fast forward to this fall and I was on a trip in the woods and I think I knocked more crud loose and started running into the same issues. Changed the filters and ultimately ended up blowing air back into the tank and no more problems. I think I'll pull the tank this winter and properly clean it.
- Thread starter
- #36
@FJmaine exactly the same thing is happening to me (except the triggering event is hills/inclining). will keep driving it locally and hope the gunk clears out. if not, i will look to cleaning the lines. (sadly, I just paid for the fuel tank to be cleaned and apparently that wasn’t too helpful).
DeskJock
SILVER Star
Save your clutch. Don’t downshift unless needed for acceleration or speed reduction.
Brake pad are cheaper and easier to replace.
Brake pad are cheaper and easier to replace.
Smoke coming up from under the dash is interesting. Every time? Coolant steam? Clutch smoke? Burnt or sweet smelling? Fuel rich exhaust? I don't see a shift boot--you sure it isn't coming up from underneath thru the floor opening?