Looking to see if anyone could help me with my 54' chevy prob?! I learn as I go. It's happened twice and it occurs when sitting for a long period idling. It will start to idle slower and slower till it finally just dies and won't restart till it cools down. I've thought about the choke, but not familiar of the ins and outs. my belief is something is heating up and shutting off the fuel supply, any and all helpmwould be great! Thanks in advance, duk
What size motor? Manual or auto choke? Gonna need some specifics for anyone to be able to help you out.
Without seeing it and hearing it, I would ***ume it is loading up with too much gas. If so, take the aircleaner off when it is warmed up. the choke flap should be all the way open. If it is partly closed, that is the problem. If it was running out of gas like you thought, it would not gradually go lower on the idle.
Sounds like it is loading up. The carb may be set too rich. Has it always done it or have you recently "tweaked" anything?
my exact thoughts. next time this happens to you, hold the throttle wide open while trying to start it again. if it is loaded up, this will generally allow the engine to start.
Choke flap is all the way open. Not really lower in idle, but it's missing and once it backfired. It's like all of a sudden the fuel is cut off. Ir starts and runs great, but the two times it's done this I was in drive thru lanes for 15-20min. Was wondering about the fuel pump?
Will it crank when it's hot? If it does, do you have spark? Fuel can get hot and cause vapor lock. Coils can get hot and not throw a spark. If it doesn't crank hot, you might be seizing up a piston or bearing but that usually won't live very long.
My first thought would be 'vapor lock'. This happens when the fuel line going to the carb gets hot enough to vaporize the liquid fuel in the line. 235s don't have crossflow heads, so that means that the carb is basically sitting on top of the exhaust manifold (hot, hot!). Looking at the fuel line going to the carb, is it close to the exhaust manifold at any point? If it is, it would be worth the time to re-route it so that there's a good air-space between the manifold and the line. If that doesn't solve the problem, we can move on to other possibilities, but I'd certainly want to rule out vapor lock first.
I was thinking along the lines as Dave B. Do you have a heat shield or heat insulator gasket under the carb?
Sometimes high under hood temps can cause vapor lock. I remember using an old trick of loosely wrapping the fuel lines with aluminum foil that are near the engine. Works great but doesn't look all that great.
Missing, backfire, I'm guessing ignition problems are present also Generally if it was fuel starved it will go lean and idle will increase untilled it was staved completely and died. Sounds more like loading up. Does winging the throttle help keep it running? What do the plugs look like? Does it have spark When it stalls and wont start Coils can get hot and fail, cool and work. Very frustrating when a coil is in its last bit of life span.
The fuel line sits about 2pm. Above the manifold. The motor will crank over when hot. It has a online fuel filter that when this occurs is dry, but normally is full when cool. The car is new to me and it runs great other than this phenomenon.
No, when it starts to die, winging the throttle makes it cut out. Like there is to much air to fuel mixture. tune up is my next priority plugs, points etc...
maybe your fuel pump is getting weak, and at idle does not move enough fuel. pull the fuel line before the pump and blow through it and make sure there are no restrictions. if no restrictions, try a new pump.
The fuel pump idles great and I've never experienced any missing or intermittent idling. Leaning more towards the heat of the engine being the problem. Whether it's the coil or vapor lock?! Just bought a coil or my other chevy, maybe I'll throw it on.
Ok if winging the throttle doesn't help then its probably not loading up. Its hard to do drivablity on the internet. If your filter is dry, ***uming cheap see Thu with chrome ends just guessing on that, that's not the best filter. Those also have a flow direction. Try a better filter or temporary by p*** it with a piece of clear hose for diagnostics only. Test your fuel pressure driving and at idle, that will point out or eliminate the fuel pump. specs for fuel pressure should be published some place. Very possible its getting week and it wont pump well at low Rpms. If fuel pressure us good start chasing a vapor lock. personally I don't start chasing vapor lock until I've verified fuel, spark, and air. Remember this: New parts don't necessarily mean good parts now adays.
No, fuel filter is plastic Bosch that I use on all my Vw's! I'm thinking I'll check the spark. I'll swap the ignition coil, new plugs etc...thanks for some direction, I really appreciate it!
I shouldnt say never, but The post about not missing and backfiring was in reference to all the regular driving. Please try to see through the posts and not try to turn this into every other post on this site! I feel there is some great knowledge and great sounding board to figure things out. But if you go back to the post it specifically says " but the two times it has happened was in a drive thru while idleing for 15-20min. I have not experienced missing other than that! Tapped out one letter at a time really slowly so to better understand me!
How have you determined that its the carb and not the coil,? Heat can effect the coil as well,, Make sure you have spark, and if not, then check for vapor lock.
Is the fuel hard or soft line If it is old soft[rubber gas line] when hot it could be ****ing shut.When it cools it allows fuel to flow again.Worth a look
My 54 did this. Fuel lines were wrapped as noted earlier and it quit. Yeah, it didn't look that great but it was a daily driver and it looked better than sitting dead at a drive thru.
That's interesting about the rubber line?! They removed a section of the hard line to put a online filter, small section of rubber at each end. I'll check to see if there is enough length in the rubber line to allow that to happen. I'm checking the coil later. Planning to build a look alike drive thru burger joint in my garage and sit at the window for 15-20 min. To get this to occur again, so I can check these possible gremlins! HaHa! I am going to see if I can get to happen again in the garage and check these things. I'm not shy about aluminum foil, but might have to find so thermal wrap! This has been a lot of help, thanks for being cool to a fng. I don't post much, but I'm always on here learning. Even from the grumpy old farts with thousands of posts!
Typing slower helped quite a bit thanks. Two kinds of Missing generally , steady rhythm that's points to a specific cylinder having a fuel, air, spark issue, or non rhythmic but constant that can generally be tracked back to that ignition system, worn dizzy, to general tune up. That's generally. Some erratic stumble is not a miss and can generally be tracked back to fuel issues. Old rubber hoses can cause fits of frustration because the can collapse internally. A bad vent on the tank can cause the same symptoms as vapor lock. If this only happens while idling for extended time periods of 15-20 mins or more -and is completely normal every other time I wouldn't be to worried about it. That would be a rare occurrence in everything except a parade
I like that " erratic stumble". That does best describe it. With all the input, which has been great. It seems the gremlin is probably in fuel delivery department or the spark side. I'll be getting a tune up and exploring the fuel system! Thanks, Gentlemen
Maybe you need to find places with faster service at their drive through! When you say there's a filter in the line, it makes me wonder if someone installed it to prevent this problem. Does the carb still have the filter? Sometimes adding a large volume filter in the line will help with vapor lock.
The in line filter is the one from Bosch that is typically used on Vw's. What would cons***ute bigger filter and would that be a replacement for the in line one. I'll check for the carb filter. My coffee is hot and the rain just set in here in the NW.
Might have found the problem, but not sure if it close enough to the motor to heat up and collapse. There is a piece of hose on the hard line from the tank just inside the engine compartment that connects to the hard line to the fuel pump. It looks like **** with a little old thrown in, I'll change it and see. Already looking into thermal wrapping all the fuel lines!
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