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Discussion Starter · #1 ·
Hi, I'm new to the site but am rreally impressed! I have a 65 Comet Cyclone that I rescued from the crusher and vitually pieced together. It has been running for two Summersbut early this June it began to act up. Finally it quit running altogether after two or three days of barely idling. When I can get it started it runs for about 15-20 seconds and dies. The carb is from a 65 Galaxy with a 352 FE. I cleaned it and put a new kit in but from day one I felt that the secondaries were not opening and that it ran extremely rich. I've rejeted it with jets for a small block and changed plugs. I am at my wits end trying to get it started!! Any help will be greatly appreciated. Thanks Tom
 

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first pull the fuel line off at the carb, get a can, maybe an extension hose to get the gas in the can and crank it over. See if your getting good fuel to it.

Take it from there.......
 

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Discussion Starter · #3 ·
Hi, Thanks for your reply! Been there done that along with new plugs, points condenser, coil, plug wires, in-line filters etc!! Thanks Again.Tom
 

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Stale gas after sitting maybe??
 

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I don't know if this is a solution to your problem, but I know it's a common thing with 4100 carbs...they are kind of honeycombed on the bottom, not a "solid" base like Holley or Carter, and it causes vacuum leaks. I put one on my truck with a slightly warmed 302, it worked fine at first, then after awhile it would start to run rough, and then came the idle problems. I then found out about the base problem and put in a carb plate (like the ones that they sell at Pony Carbs) and it took care of the problem. If you are wondering what I mean by carb plate, it is basically just a flat piece of metal that fits between the base of the carb and the intake...seals it up so there is no vacuum leaks.
Hope it may help!
Mike

<font size=-1>[ This Message was edited by: Humphrey351 on 10/10/06 10:47am ]</font>
 

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he should still be able to keep it running with vacuum leaks.....

put a timing light on it and a fuel pressure gauge and watch them while it runs for the 20 seconds...see witch one stops working. If they both stay steady meaning the light works and the pressure stays steady I would try a different carb.

Go from there.

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<font size=-1>[ This Message was edited by: 393Clevor on 10/10/06 6:38pm ]</font>
 

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My 67 Mustang did the same thing with my 289 and the 4100 carb. Go to NAPA and ask them for their glass fuel filter. It is not on the shelf most of the time. Install it right before the carb and see if it fills up at first and then after a while of running then it will only be partially full. If it does not fill up all the way after a while, then you probably have old and clogged fuel lines or a bad sending unit sock with crap at the bottom of the tank. If you have good fuel delivery that glass filter will be full all the time.
Also try opening your gas cap while running--sometimes the system can create a vacuum and shut down. Those old cars had vented gas caps or vent tubes underneath that might not be working properly.

<font size=-1>[ This Message was edited by: 67VertMustang on 10/10/06 10:34pm ]</font>
 

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This is a common problem with the 4100's on small blocks. Most people think they can get a 4100 off of anything and install it on anything and that it should run right. Well if you get a 4100 from a 352-390 engine and install it on your 289-302, you will have the exact symtoms that you describe as the big block carb is metered for a larger engine and changing jets to small block jets will not solve the problem. The carbs are designed for particular engines, the 1.12 carbs are the big block carbs with the 1.08's being the small block carbs. There are some 1.12 Hi-Po carbs that are designed for small blocks, but they are extremely rare. There are also some 1.08 California emissions carbs that are designed for big blocks that will not work with the small block engines. There is an awesome website called the Ford Carburetor Forum run by a man named Bill White that is an absolute wizzard with these carbs, that is the place I got all my information about the 4100's when I was rebuilding the 4100 on my '65 Mustang.
 

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I know I'm getting old and I forget things. But isn't there a small brass fuel filter in the carb where the fuel line connects to the carb? Maybe that was a Rochester carb. I know that when those got plugged the engine acted exactly like you described.
 

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Discussion Starter · #12 ·
Wow! Thanx to everyone who took the time to answer my post! I particularly like the suggestions from Hump about the base plate and the inside info on the differences in 1.08's and 1.12's. The carb in question came off of a 352 in a Full sized Ford. Thanx Again to all. PS, keep thosee GGGGRRReat suggestions comin!! Tom
 

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okay, I think before we go on too much further with this, it's time to get more info on the engine itself...you say you put in small block jets, well then I assume it is a small block you have in it, but what displacement (260, 289, 302, 351?), what about the cam you are running? exhaust system? timing? Give us as much info as you can/know about the set up...and we may all be able to get you a few more ideas about what could be ailing that carb of yours.
Like Cupcake said, the big block variants of the 4100 don't always work well on small blocks (however, I ran a 4100 from a 390 on my .20 bored over 302, running stock cam for 1983 and 9.0:1 compression, and it ran fine after I discovered the bottom vacuum leaks)...the 1.08 is better suited to smaller displacements, and surprisingly you can still get some decent ones off Ebay..so keep looking!
But first, get us the important details so we can all make a better diagnosis on the carb problem.
Good Luck!
Mike
 

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It runs and then dies..................You could put a 1150 on it and it would stay runing.

It's either it's not getting fuel (or maybe flooding out) or it's loosing ignition....that simple...

does it dump a ton of black smoke when it does start?
 

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You did say it was running for 2 summers before so it can't be that it's the wrong cfm for the engine. I'm with clevor, not getting fuel because of filter clog, fuel pump bad or tank end is clogged. I had a super bad vacuum leak on mine that showed after puting the carb back on and the spacer was warped. That durn thing sounded like a vacuum cleaner with a peice of paper stuck in the end of the hose but had no trouble running. So I'm against the vac leak also.

Nolan you're right, there is supposed to be a wire screen in the carb where the fuel line hooks up.

Deb
 

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Discussion Starter · #16 ·
Hi, in response to Humphrey 351 The engine is bored .030, runs a Ford Motor Sport A312 cam with matched lifters,pushrods,and valve springs. I amrunning stock exhaust manifolds because of clearence problems in the Cyclone. Intake is a Weiand Action Plus. Pistons are Speed-Pro 10 to 1 cast. high volume oil pump and double roller timing chain. Ignition is stock with timing set at 12* initial and 34* total. I guess tats it. Like I said it ran like a scalded dog for two years! Thanks Again!! Tom
 

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If you ever want to, the Heddman 88400's will fit, and though a little more pricy, the Hooker Super Comps will fit nicely.
 

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The early 60's 4100 also had sock-like strainers underneath
the seat assembly (needle/seat) in the float bowls. You
might check to see if they're present and clogged. Usually
they were discarded the first time the carb was rebuilt, but
you never know. Unscrew the seats from the main body &
take a look......
 

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Yes, THERE IS supposed to be a brass filter before the carb. What I was suggesting was to replace that with a glass filter. I did that to diagnose my 4100 1.08 venturi carb (with was from a 62 big block T-bird and worked great with my new mild cam). I just left the glass filter on after I figured it out. It lets you know what is going on with fuel delivery.
 
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