could this cause that???? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

76lwb · 11-25-2002, 03:23 PM

could a slightly pluged pickup (in tank) cause a off idle stuble or hestation?

ElGracho · 11-25-2002, 04:16 PM

Yes, a clogged pickup could cause that, but I'm thinking their are a lot of problems that are more likely.

such as:

bad accel pump in carb
incorrectly adjusted carb
Fuel filter
fuel pump
fuel tank selector valve getting stuck in middle

etc...

Give us some more symptoms and background.

76lwb · 11-25-2002, 05:07 PM

new 1406, tried all three hole for the accel pump. i have a electric fuel pump @4.5 psi, new filter before pump and again before carb.

ive adjusted the timing to 10*btdc with vacuum advanced unpluged and capped.

ive done the "seat the vavles and back out 2 turns" and then tuned with vacuum and tach (850rpm and max vacuum which was around 19.5") i havent done this in drive yet. i dont want to trust a block in front of the tire and the ebrake.

the coil, module, cap, rotor, wires and plugs are all new and i checked the mechanical advance weights and springs and gave them a little squirt of wd40. ive also double checked firing order.

ive also did the carb cleaner to check for vacuum leaks. never reved or die.

as far as the selector switch i have it bypassed just to know it wasnt that.

it has a performer intake and ive just bought it about a week ago and it had a 750 on which made it run rich as hell.

the truck has 107k on it but i know no history of the truck. it looks stock (and rough).

the electric pump will make a load noise as if its not pumping fuel and then sometimes i cant hear it at all. so im thinking that the pick up is clogged. time to drop the tank.

it has a great idle, and i know it could use a little more tuning to get a little more power.

76lwb · 11-25-2002, 06:47 PM

well i just switched to the other tank (bypassing tank selector valve) and the filter looks different. the driver side fills up the filter where as the passenger side looks like it can barely keep up.

but either way it still bogs under light throttle, come to think of it it seems to cut out more when making left turns from a stop.
im begining to think it the floats but thats why i posted om here to see what everyone else thinks.

76lwb · 11-25-2002, 07:09 PM

well im going to try a .073x.042 and a silver colored spring tomorrow, hope it helps.

Tom · 11-25-2002, 07:12 PM

I thinks its a eddy carb problem. My 79 does the same thing. Brand new engine, new carter 600cfm, new ignition set at 10 degrees, new cater fuel pump with regulator set, new fuel filter, float levels set, A/F mixture perfect, and still it stumbles off idle.

**swervin ervin** · 11-25-2002, 09:55 PM

Tom,

I'll tell you how to fix the Carter. Take it off and install a good Q-jet. Problem solved.

TODDS 72 · 11-25-2002, 10:02 PM

I agree with mike,I got a tool just for that ..........Its called a 10lb hammer..........LOL

CustomChevy · 11-26-2002, 12:31 AM

i had noticed that you said the fuel pump is pushing out 4.5 gph....is this an in-tank pump you have or is it out of the tank? 4.5 is way low. you should have at least 6. pump might bad.

change out fuel filters too, they're cheap anyway.
also, try 8 degrees instead of 10.

good luck!

76lwb · 11-26-2002, 09:39 AM

well the edelbrock manual says to set it at 5.5psi, and that fuel pressure should not fall below 2 psi. its a inline pump mounted to frame rail. im not sure on the gph im going by psi.

its not knocking or pinging so i would think 10* would be ok.

ill resest the time after i change the metering rod and step spring.

thanks guys

76lwb · 11-26-2002, 09:04 PM

Well the metering rods and step up springs helped with the bog just off idle. So far so good. Ive decided to get the edelbrock fuel pump to go with the performer carb. I dont like hearing the pump.

11-25-2002, 03:23 PM	#1
76lwb Registered User Join Date: Nov 2002 Location: springfield,mo Posts: 7	could this cause that???? could a slightly pluged pickup (in tank) cause a off idle stuble or hestation?

11-25-2002, 04:16 PM	#2
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,550	Yes, a clogged pickup could cause that, but I'm thinking their are a lot of problems that are more likely. such as: bad accel pump in carb incorrectly adjusted carb Fuel filter fuel pump fuel tank selector valve getting stuck in middle etc... Give us some more symptoms and background. __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed

11-25-2002, 05:07 PM	#3
76lwb Registered User Join Date: Nov 2002 Location: springfield,mo Posts: 7	new 1406, tried all three hole for the accel pump. i have a electric fuel pump @4.5 psi, new filter before pump and again before carb. ive adjusted the timing to 10btdc with vacuum advanced unpluged and capped. ive done the "seat the vavles and back out 2 turns" and then tuned with vacuum and tach (850rpm and max vacuum which was around 19.5") i havent done this in drive yet. i dont want to trust a block in front of the tire and the ebrake. the coil, module, cap, rotor, wires and plugs are all new and i checked the mechanical advance weights and springs and gave them a little squirt of wd40. ive also double checked firing order. ive also did the carb cleaner to check for vacuum leaks. never reved or die. as far as the selector switch i have it bypassed just to know it wasnt that. it has a performer intake and ive just bought it about a week ago and it had a 750 on which made it run rich as hell. the truck has 107k on it but i know no history of the truck. it looks stock (and rough). the electric pump will make a load noise as if its not pumping fuel and then sometimes i cant hear it at all. so im thinking that the pick up is clogged. time to drop the tank. it has a great idle, and i know it could use a little more tuning to get a little more power. Last edited by 76lwb; 11-25-2002 at 05:15 PM.*

11-25-2002, 07:12 PM	#6
Tom driving is in my blood Join Date: Dec 1999 Location: Mesa AZ Posts: 5,714	I thinks its a eddy carb problem. My 79 does the same thing. Brand new engine, new carter 600cfm, new ignition set at 10 degrees, new cater fuel pump with regulator set, new fuel filter, float levels set, A/F mixture perfect, and still it stumbles off idle. __________________ -78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me.

11-25-2002, 09:55 PM	#7
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	Tom, I'll tell you how to fix the Carter. Take it off and install a good Q-jet. Problem solved. __________________ Mike 1985 Chevy C-10

11-25-2002, 06:47 PM	#4
76lwb Registered User Join Date: Nov 2002 Location: springfield,mo Posts: 7	well i just switched to the other tank (bypassing tank selector valve) and the filter looks different. the driver side fills up the filter where as the passenger side looks like it can barely keep up. but either way it still bogs under light throttle, come to think of it it seems to cut out more when making left turns from a stop. im begining to think it the floats but thats why i posted om here to see what everyone else thinks.

11-25-2002, 07:09 PM	#5
76lwb Registered User Join Date: Nov 2002 Location: springfield,mo Posts: 7	well im going to try a .073x.042 and a silver colored spring tomorrow, hope it helps.

11-25-2002, 10:02 PM	#8
TODDS 72 Not the nightly winner Join Date: Jul 2002 Location: CHARLEMONT MA.USA Posts: 763	I agree with mike,I got a tool just for that ..........Its called a 10lb hammer..........LOL __________________ 72C10SWB BLUE 350/350 86K10LWB BLUE 5.7 700r4 7.5' fisher plow 93S10XCAB4X4 BLUE 4.3 4L60e 69gmc c10 v8 3 on the tree yellow 72k10 swb 350 3 on the tree green 86k15 swb5.0L 4spd brown

11-26-2002, 12:31 AM	#9
CustomChevy Registered User Join Date: Nov 2002 Posts: 462	fuel pump i had noticed that you said the fuel pump is pushing out 4.5 gph....is this an in-tank pump you have or is it out of the tank? 4.5 is way low. you should have at least 6. pump might bad. change out fuel filters too, they're cheap anyway. also, try 8 degrees instead of 10. good luck!

11-26-2002, 09:39 AM	#10
76lwb Registered User Join Date: Nov 2002 Location: springfield,mo Posts: 7	well the edelbrock manual says to set it at 5.5psi, and that fuel pressure should not fall below 2 psi. its a inline pump mounted to frame rail. im not sure on the gph im going by psi. its not knocking or pinging so i would think 10* would be ok. ill resest the time after i change the metering rod and step spring. thanks guys

11-26-2002, 09:04 PM	#11
76lwb Registered User Join Date: Nov 2002 Location: springfield,mo Posts: 7	Well the metering rods and step up springs helped with the bog just off idle. So far so good. Ive decided to get the edelbrock fuel pump to go with the performer carb. I dont like hearing the pump.



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