Cascade Crew

kurfbird · Last edited by kurfbird on Sun Nov 28, 2010 6:12 pm; edited 1 time in total

Okay was coming home from shoping on friday and the truck started surging going up a hill.

I am runiing and edelbrock 2101 intake and and edelbrock 1406 carburator. the carb was rebuild in april

Did a compression test getting 150-165 on all cylinders. before intake gaskets replaced. USe the edelbrock intake gasket

Installed new intake gaskets and torque them. Found some loose middle bolts so I thought that was the problem.

Also running a bowtie overdrive set up for the 700r4 transmission shift.

Installed new carb gaskets X2 . Still runs but cant acclerate.. Will idle surges while trying to drive it up hill.

I took the screw down to barly running and hit it with carb cleaner on the carb gasket no improvmemt. hit on the side of the carb near where the rods come out on drivers side car inproved on idle.

installed new fuel pump on friday

I just seem to be at a loss on what is going on here

aaron_sK

How does the vacuum gauge look? How's fuel pressure? Is there slop in the throttle shafts on the carb?

kurfbird · Posted: Sun Nov 28, 2010 6:09 pm Post subject: Vaccum

Vaccum

is about 19 when carb is adjusted properly. top of the green scale.
Fuel pressure is 6-8 PSI. Buld my own fuel pressure tester. Cant seem to get one for carburator anymore.

Will check throttle shaft

Also forgot to add installed new fuel pump on friday

Twilightoptics · Posted: Sun Nov 28, 2010 6:39 pm Post subject:

Fuel Filter?

kurfbird · Posted: Sun Nov 28, 2010 6:56 pm Post subject: New

New also replaced on friday. There is some play in the throttle shaft. up and down if I grasp on it

chevymad · Posted: Sun Nov 28, 2010 8:12 pm Post subject:

There's always some play in the throttle.. Vaccuum leak will make it not want to idle.

Is it a slow surge or quick jerk? Slow.. probably fuel supply. Check your pressure while driving .. tape gauge to windsheild. Quick its most likely something in the ignition. Cracked plug, wire, or cap causing crossfire under load.

kurfbird · Posted: Sun Nov 28, 2010 8:25 pm Post subject: Okay

But if I spray the side of the carb where the rods come out the car idles better when I ahve the front valves adjusted closed ??

chevymad · Posted: Sun Nov 28, 2010 9:22 pm Post subject:

Yes, because there actually is a leak there. But you can pretty much do the same to any carb, unless its a sealed blower carb. None are totally sealed there. The only time it is real trouble is if you can't adjust the idle mixture screws for a good idle. Or if the shaft is so worn the butterfly's rub the venturi. If you can adjust for a good idle then the leak will be compensated for all across the curve.

Was this running good and then went to crap? Or is this something that just happened all of a sudden?

From your description, i'd be looking at either the fuel pump or the pickup sock. It is possible to have an internal carb problem. But not likely.

A vacuum leak screws up the idle much worse then cruise. If you think about it. The amount of air in a leak is a much higher percentage of total air intake at idle, then at cruise. So the afr will be skewed lean alot more at idle then cruise.

kurfbird · Posted: Sun Nov 28, 2010 9:40 pm Post subject: was running good

Was running good and friday went to crap. Was not a slow problem it went bad very quickly.

chevymad · Posted: Sun Nov 28, 2010 9:42 pm Post subject:

I think that rules out the throttle shafts then.

Get your fuel pressure tester hooked up and take the rig out and try it. See if it holds pressure while the problem occurs.

90droptoproc · Posted: Sun Nov 28, 2010 9:48 pm Post subject:

did you fill up right before this???

kurfbird · Posted: Sun Nov 28, 2010 9:48 pm Post subject: I will

I will just depends when I get off work

kurfbird · Posted: Sun Nov 28, 2010 9:54 pm Post subject: fill up

IROCDave · Posted: Mon Nov 29, 2010 6:00 pm Post subject:

If it has a HEI I would be looking at this the ignition module. Usually they just go out, but it can be intermitten also.

http://www.summitracing.com/search/Department/Ignitions-Electrical/Part-Type/Ignition-Modules/

kurfbird · Posted: Mon Nov 29, 2010 7:19 pm Post subject: I think I found the problem

I think I found the problem. A broken clamp that hold the fuel lines / hoses on teh frame near the gas tank. The hoses are getting pinched causing fuel to be restricted wont know for sure till I get it fixed. I though about it then look at it this morning before work with a flash light.

kurfbird

Okay I fixed the clamp still doing the same thing except

When its cold and just started took it up the same hill near my house about 5 times

1 time good to go
2nd time surged a little
3rd surge more I adjusted carb 2.5 turns out.
4th time surge worse and stalled
5th time barly got up the hill. no power at all and tried to stall was worried about getting it home.

It runs worse as it warmed up.

I am think that its igntion related. Fuel I dont think would do that. Correcte me if I am wrong.

So its can probably be
Cap
Rotor
Coil

Igntion module Replaced in June
Spark plugs were repalced in June also (they looked good when I had them out for the compression test)
Wires (Got them new a less than a month ago)

chevymad · Posted: Mon Nov 29, 2010 9:01 pm Post subject:

Is the tank venting right?

New means nothing. Don't assume its good because its new.

kurfbird · Posted: Tue Nov 30, 2010 6:39 am Post subject: Tank vent

It seems to vent okay but will run it with the cap loose and see waht happens

Twilightoptics · Posted: Tue Nov 30, 2010 8:15 am Post subject:

Adjustment screws you turned out only affect idle characteristics.

blue89 · Posted: Tue Nov 30, 2010 9:20 am Post subject:

I would think a weak spark could cause these symptoms. Have you checked to see how its doing?