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Discussion Starter #1
the 351w engine i just put in my cougar came from a 5 speed mustang fox body drag car.all new parts when built 1 year ago,highly modified with 750 holley duel line double pump,he had the same problem i'm having except it could overcome it by being straight drive,he had to launch @6000 rpm or car would bog down,my problem from idle to wide open throttle the car shuts off,i can pat the throttle it's ok,but you can't race an automatic that way,the engine accels great,idle's great and has great throttle response,i have 7 1/2 lbs fuel pressure,good fuel flow,i tried #28,#31,#35 squirters,it has #78 front #80rear jets,i have 0015 pump lever clearance......idle screws adjusted in,out all makes no difference,any ideas?:confused:
 

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Ask Ty at TCP Racing. He is a carb specialist. He normally floats around FordMuscle.com but you can email him direct at [email protected]. He is very helpful with fuel issues.
 

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The problem is simply fuel stavation. Believe it or not. Jets are not going to help.

Here's what I see wrong in your description. The pump lever must have ZERO clearance in it at idle. The .015" is only at WOT. You must be able to compress the spring the additional .015".

I have had similiar probs. If the slightest amount of throttle angle is made without acc. pump movement you're screwed.

If this seems not to be the problem it still comes back to starvation. Being a DP you might need to go to the .042" and larger squirters which require the hollow screw. And you are running the pink cam on the primary?

Have you tried any other carbs?
 

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I am having a similar problem. Idles fine, then hit the gas to take off. Nothing. She shuts her self off.

Edsel, does it occur when the engine is hot or cold? Mine is fine initially, first start and take off. Once it gets warmed up...........Say good night Gracie. I'm sorry to horn in on your thread, but I have been chasing this since last summer. I am EXTREMELY curious to see how you make out.
 

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Holley Carburetor Problems

From the looks of the first post, you are having problems with severe bogging. But it becomes elimnated at a high RPM launch.

is this a 'stock' carburetor? What model number is it? Who built it if customized?

This is more than likely your problem...

Your idle speed screw is too far in, meaning you have way too much transition slot exposed. This is allowing your motor to breathe of the slot for idle fuel and not the curb idle. This is noticeable because the idle mixture screws are not responding.

Now with the transition slot back to within 0.025"-0.045" MAX exposure, your idle mixture screws set for a good RPM and vacuum reading, you need to find the 'bogging' problem.

You tried many new sizes of squirters, but did you think about adding a 50cc pump? Most drag cars require this in order to fuel the motor under a hard heavy launch.

What type of intake manifold do you run? If it's an open/single plane then you MUST have that primary 50cc shot accelerator pump. Use a size 32 squirter for starters then move up until the bog dissappears.

Set your floats to normal level and lower your jets one size. Now run your car for the best 60' time. Did it record lower this time? I bet it did.

Now run the car for the best ET MPH. Raise your rear jets to gain MPH until it dies off. Then lower your jets back to the best run. Now it's time for some float adjustment. This is where fine tuning comes in (1/4 turn up-rich or down-lean).

This should clear up alot of confusion. It looks like your fuel pressure is right on, but your idle/transition is all d*&ked up.

Good luck and call me if you need any assistance what so ever. Advice is free...:D
 

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Engine Specs Request

Please provide me with all of your engine specs.

bore/stroke
cam specs- center(crank and cam), duration, lift, part #
tire height
stall speed
ZIP code you race at (altitude densisty figures)
Intake manifold type
head type (mods if any)


Thanks

~Ty
 

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Discussion Starter #11
thanks guys,i just got back from california,tpc i will get all the info asap.so far i know 351w,steel crank,mild cam, trick flowalum. heads with extensive head work,holley 750 carb 78 jets front 80 rears, #35 shooters,28.5 inch tall slicks,.wiend stealth intake,holley red fuel [email protected] lbs , zip code 27021 more info to follow when i get hold of engine builder.i ran a 7.36 @92mph in 1/8th weighing 3080lbs.with bad stumble at start,had to double hit the gas .the car DIES from idle to wide open throttle or 2800rpm to wot,in the other car he had 5 speed and had to stall up to 6000rpm or it would die....he ran low 7.20's with 373 [email protected] lbs.,mine a 488...all help is greatly appreciated guys....
 

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Discussion Starter #13
would you believe i took a 1/16th drill bit,drilled out a #28 shooter.put it in the rear,left the #35 in front and it almost has cleared the problem,i can go from 2300 rpm to wot with no bog or engine shut off or smoke,getting some real holley shooters tomorrow,nobody in this neck of the woods has any holley parts on hand
 

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Discussion Starter #14
got the #40's today,installed with the hollow screws and wow!!!!!! this baby screams now....1100 rpm to wide open no a miss!!!!!!!!!!!and with those open headers she sounds sweet!!! thanks so much to all who responded,,,,it's good to know that there are good folks willing to help others....if i can be of help....just ask
 

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Sheesh...I wish I knew somethin' about carbs...mine really screamed when I had the guy at the local speed shop tune it after the rebuild, but then had to tweak it for smog...now that I don't hafta smog it, I later took it to an "expert" on carbs since the first guy left the area...and it does "OK" now, but it's STILL like kissin' yer sister (ummmm...not that I would KNOW about that...:lol2: ).

I'd love to get it screamin' again...someday I will...prolly just hafta go to a SCCC meeting sometime *LOL*
 

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Sunday when I came back from LA after the Fab Fords I had a similar problem with my Holley on the CJ. It would rev up OK, even a little around town, but as soon as I hit the freeway it bogged and starved. Even though I just had the carb rebuilt it wasn't set up right.

I had it towed to the first place (they weren't open on Sunday) but they didn't know much about carbs anyway. They refered me to Mastercraft in Garden Grove (714) 638-2671 and flatbedded it over. Jim fiddled with it, seemingly got it to idle perfectly at 600, no shake at all. The float needle was messed up I think. So I took it out for a test spin, it seemed perfect, even on the short freeway trial. Then I took off to go back to San Diego! I got three exits away....same dang thing. I got towed for the THIRD time, Jim stayed open past 6PM to help me out. He dug a little deeper and found some crud and in the inner filter (I'm not a mechanic, but it looks like a brass plated cylinder coral?) it was completely blocked.

I was a little spooked, but he really got it to go. Now it's running like a good Holley/CJ should run! A day late, but I finally got home.
 

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Well Since we're talkin carbs here How 'bout this.... the 67 does the following.... When first starting I have to pump livin' sh*t out of it and keep the idle @1500 or so 'till she warms up. Then it starts fine the rest of the day. then from a dead stop if I punch it it goes great ... but that usually smokes the tires (bad thing in the city... trust me) when I try to start slow it will bog and almost die so I have to flutter the pedal. acceleration at speed ... no problem (15-90mph) and finnaly when doing highway speeds there is a slight surge not very much but definately detectable... Stock 289, stock ford 4V carb.... I've swapped the fuel filter,adjusted the auto-choke, changed the points.....run 91 oct unleaded. the carb is relatively new-rebuilt I was told it needed to be "dialed in"... ????? idles great once it's warm any ideas??
 

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Sounds like choke issues to me. Or the mixture is too lean even with the choke working.
 

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idle mixture screws or jetting issue?
 
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