Help carb probelm I think - The 1947 - Present Chevrolet & GMC Truck Message Board Network

lamar · 03-09-2005, 04:21 PM

Ok I have a new goodwrench performance 350 the one that comes with everything from the pan to the carb. The carb is a holley 600 the one that came on it. The probelm is when you just stomp it from dead stop or while moving it stalls out almost to the point of killing the motor. What do I look at first, carb, choke, timing,what? I just changed the plugs and installed a 700r4. It did the same thing before the 700r4 maybe not as bad but it still did it. Thanks for any help!!!!!!!!!!

shifty · 03-09-2005, 04:39 PM

Actually, this will sound stupid, but it sounds like a clogged or bad fuel filter. Thing is, I'm still not well-versed enough with these trucks to know if they even have one. I remember my '85 Grand Am had the exact same problem; wound up being the fuel filter.

Being these things aren't fuel-injected, I can't see why you'd have a fuel filter so I'll just shutup now.

lamar · 03-09-2005, 06:08 PM

Thanks but yes I have a fuel filter at carb, the clear type. Installed it at the same time as motor. Less than 1600 miles on both. Any other ideas anybody?

flip66 · 03-09-2005, 08:00 PM

If you have HEI it could be the wire going from the pick up to the control module in the distributor. I went nuts trying to figure out the same type of problem when I punched it the wire would lose contact for a second then and the car felt like it just cut off then the wires would contact and it would go it would not do it under normal driving conditions.

PMS · 03-09-2005, 08:39 PM

After the stall does the engine seem to catch up? Also is this a 350HO motor?

lamar · 03-09-2005, 09:57 PM

Yes it stalls and it will catch back up. It's the GOODWRENCH Performace 350 Deluxe crate engine. I just looked it up and it is the 350HO with 330 hp. Any ideas? And thanks for the coil wire idea but I checked that already.

lamar · 03-09-2005, 09:59 PM

Correction it's not goodwrench it just says GM Performace 350 HO Deluxe. It's the one in summit and Jegs.

**53burb** · 03-09-2005, 10:55 PM

Aside from that problem you"re having, how do like that engine?? I was considering getting that engine next year??

Solver · 03-09-2005, 11:04 PM

I don't know holley carbs but if it was a quadrajet I would say you should try moving the linkage from one hole to the other above the accelerator pump piston. might double check timing and vaccum advance also.
don't know if holleys are set up the same for linkage though

lamar · 03-09-2005, 11:29 PM

Could it be the choke not adjusted right? I'll look into the linkage deal it could be. Timing could be It. Another thing I just thought of is that it cranks great on the first try like instantly, the first start of the day, but after that it takes a little more turning of the motor to start. Could this be part of the same problem? Aside from the few things I'm telling you about Ilove the motor. As you can tell I'm not even a shade tree mechanic, I'm just a want be trying to save a trip to a pro. The install was a no probelm just plug and play really.

**VetteVet** · 03-09-2005, 11:43 PM

Lamar. You said you changed the transmission did you plug the vacuum line for the vacuum modulator. I read that you said it did it before you made the change but it sounds like a vacuum leak to me. Also the choke might be set too rich which would explain why it starts fine cold but needs to spin when warm. Just some ideas to ponder.
VetteVet

jhow66 · 03-09-2005, 11:48 PM

Lamar I have installed a couple of these engines. Good engine. 1st you need to set the timing @ 10* before top dead center. Next adjust each of your idle mixture screws out 1 1/2 turns from closed. Then make sure your pump arm is moving the EXACT same time as your throttle shaft. If this does not cure it you will need to change your pump squirtor from a 25 (should be whats in it now) to a 28. If this is more then you can do, go ahead and let some one that has the know how tune it for you . When you get it tuned in you will be very happy with it. Good strong running street engine.

PMS · 03-10-2005, 11:03 AM

Not to change the subject but if anyone is going to buy the GM HO 350 contact me before about the problems I have encountered about this engine.

jhow66 · 03-10-2005, 12:13 PM

Quote:

Originally Posted by PMS

Not to change the subject but if anyone is going to buy the GM HO 350 contact me before about the problems I have encountered about this engine.

Would be interested in what problems you had.
Howard

JBstor · 03-10-2005, 01:02 PM

Just in case, check to see that the vaccum advance is holding vaccum. Years ago mine was leaking on the HEI and there was a REAL bad dead spot when you accelerate.

If it is leaking you lose vaccum, AND advance at the same time. It only takes a couple of minutes to check.

HTH
JB

lamar · 03-10-2005, 05:50 PM

I would be interested also. What is going wrong for you. How do you check the vaccum advance? Vaccum gauge I would assume, but where to connect and what to do?

CHEVIBUBBA · 03-11-2005, 03:36 AM

you need to read your plugs!
engine at normal operating temp.get it on a lonely road up to hiway cruising speed for about 30 seconds then kill the engine & coast to the edge.pull a plug & look at the tip.black means rich, white means lean, greyish white is right!
if it's black/sutty the main metering is too rich/jet too big.white means jet too small.
runit down the road as before then stop & stomp on it like you originaly posted.when the stall seems to be at it's worse kill the engine & pull a plug.
is the plug clean or black & sutty?
if it's clean your accelerator pump is too lean.
if it's black & sutty or maybe wet with fuel the accel. pump is too rich.
i'm betting too rich as manufacturers/rebuilders typicaly build on the rich & safe side vs. lean/go boom side.
the shooter nozzle is probably too large.
i highly recommend you get a holley education via books or take it to an experienced pro.they are simple carbs but, you can sure mess "em up if your ignorant of the design.
also, when setting the idle mixture screws use a vacuum guage & set them for the highest reading.adjust the idle speed as needed to maintain the recommended speed.
you'll be happier with 12 deg. initial advance @ idle.

03-09-2005, 04:21 PM	#1
lamar Registered User Join Date: Apr 2004 Location: Covington,Ga Posts: 453	Help carb probelm I think Ok I have a new goodwrench performance 350 the one that comes with everything from the pan to the carb. The carb is a holley 600 the one that came on it. The probelm is when you just stomp it from dead stop or while moving it stalls out almost to the point of killing the motor. What do I look at first, carb, choke, timing,what? I just changed the plugs and installed a 700r4. It did the same thing before the 700r4 maybe not as bad but it still did it. Thanks for any help!!!!!!!!!! __________________ 72 C-10

03-09-2005, 04:39 PM	#2
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Actually, this will sound stupid, but it sounds like a clogged or bad fuel filter. Thing is, I'm still not well-versed enough with these trucks to know if they even have one. I remember my '85 Grand Am had the exact same problem; wound up being the fuel filter. Being these things aren't fuel-injected, I can't see why you'd have a fuel filter so I'll just shutup now. __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

03-09-2005, 06:08 PM	#3
lamar Registered User Join Date: Apr 2004 Location: Covington,Ga Posts: 453	Thanks but yes I have a fuel filter at carb, the clear type. Installed it at the same time as motor. Less than 1600 miles on both. Any other ideas anybody? __________________ 72 C-10

03-09-2005, 08:00 PM	#4
flip66 Registered User Join Date: Jan 2004 Location: Garland TX Dallas area Posts: 658	If you have HEI it could be the wire going from the pick up to the control module in the distributor. I went nuts trying to figure out the same type of problem when I punched it the wire would lose contact for a second then and the car felt like it just cut off then the wires would contact and it would go it would not do it under normal driving conditions. __________________ 1998 Pontiac Grad Prix GTP 1969 C10 396 TH400 3.08 posi

03-09-2005, 09:57 PM	#6
lamar Registered User Join Date: Apr 2004 Location: Covington,Ga Posts: 453	Yes it stalls and it will catch back up. It's the GOODWRENCH Performace 350 Deluxe crate engine. I just looked it up and it is the 350HO with 330 hp. Any ideas? And thanks for the coil wire idea but I checked that already. __________________ 72 C-10

03-09-2005, 08:39 PM	#5
PMS Registered User Join Date: Aug 2004 Location: Overland Park, KS Posts: 79	After the stall does the engine seem to catch up? Also is this a 350HO motor?

03-09-2005, 09:59 PM	#7
lamar Registered User Join Date: Apr 2004 Location: Covington,Ga Posts: 453	Correction it's not goodwrench it just says GM Performace 350 HO Deluxe. It's the one in summit and Jegs. __________________ 72 C-10

03-09-2005, 10:55 PM	#8
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,005	Aside from that problem you"re having, how do like that engine?? I was considering getting that engine next year??

03-09-2005, 11:04 PM	#9
Solver Registered User Join Date: May 2000 Location: Storm Lake, Ia Posts: 1,449	I don't know holley carbs but if it was a quadrajet I would say you should try moving the linkage from one hole to the other above the accelerator pump piston. might double check timing and vaccum advance also. don't know if holleys are set up the same for linkage though __________________ 1972 Cheyenne Super 20 LWB-Blue 1972 Cheyenne Super 10 LWB-Black 1972 Cheyenne Super 10 LWB-Red 1972 Cheyenne Super 10 LWB-green 1972 GMC 4x4 LWB-White 1971 Cheyenne 10 LWB-Ochre 1971 Cheyenne 20 Longhorn-Copper 1971 Cheyenne 20 Longhorn-Black 1969 Custom 10 LWB-lt blue 1968 GMC 3/4 ton-green 1968 1/2 ton swb stepside-silver 1967 Chevrolet CST 10 LWB-green 1967 Chevrolet custom 20 LWB-Maroon

03-09-2005, 11:29 PM	#10
lamar Registered User Join Date: Apr 2004 Location: Covington,Ga Posts: 453	Could it be the choke not adjusted right? I'll look into the linkage deal it could be. Timing could be It. Another thing I just thought of is that it cranks great on the first try like instantly, the first start of the day, but after that it takes a little more turning of the motor to start. Could this be part of the same problem? Aside from the few things I'm telling you about Ilove the motor. As you can tell I'm not even a shade tree mechanic, I'm just a want be trying to save a trip to a pro. The install was a no probelm just plug and play really. __________________ 72 C-10

03-09-2005, 11:43 PM	#11
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,714	Lamar. You said you changed the transmission did you plug the vacuum line for the vacuum modulator. I read that you said it did it before you made the change but it sounds like a vacuum leak to me. Also the choke might be set too rich which would explain why it starts fine cold but needs to spin when warm. Just some ideas to ponder. VetteVet __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

03-09-2005, 11:48 PM	#12
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Lamar I have installed a couple of these engines. Good engine. 1st you need to set the timing @ 10* before top dead center. Next adjust each of your idle mixture screws out 1 1/2 turns from closed. Then make sure your pump arm is moving the EXACT same time as your throttle shaft. If this does not cure it you will need to change your pump squirtor from a 25 (should be whats in it now) to a 28. If this is more then you can do, go ahead and let some one that has the know how tune it for you . When you get it tuned in you will be very happy with it. Good strong running street engine. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer Last edited by jhow66; 03-09-2005 at 11:49 PM. Reason: change spelling

03-10-2005, 11:03 AM	#13
PMS Registered User Join Date: Aug 2004 Location: Overland Park, KS Posts: 79	Not to change the subject but if anyone is going to buy the GM HO 350 contact me before about the problems I have encountered about this engine.

03-10-2005, 01:02 PM	#15
JBstor Registered User Join Date: Feb 2005 Location: Winnipeg, Manitoba, Canada Posts: 66	Just in case, check to see that the vaccum advance is holding vaccum. Years ago mine was leaking on the HEI and there was a REAL bad dead spot when you accelerate. If it is leaking you lose vaccum, AND advance at the same time. It only takes a couple of minutes to check. HTH JB

03-10-2005, 05:50 PM	#16
lamar Registered User Join Date: Apr 2004 Location: Covington,Ga Posts: 453	I would be interested also. What is going wrong for you. How do you check the vaccum advance? Vaccum gauge I would assume, but where to connect and what to do? __________________ 72 C-10



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03-11-2005, 03:36 AM	#17
CHEVIBUBBA got boost? Join Date: Mar 2005 Posts: 123	you need to read your plugs! engine at normal operating temp.get it on a lonely road up to hiway cruising speed for about 30 seconds then kill the engine & coast to the edge.pull a plug & look at the tip.black means rich, white means lean, greyish white is right! if it's black/sutty the main metering is too rich/jet too big.white means jet too small. runit down the road as before then stop & stomp on it like you originaly posted.when the stall seems to be at it's worse kill the engine & pull a plug. is the plug clean or black & sutty? if it's clean your accelerator pump is too lean. if it's black & sutty or maybe wet with fuel the accel. pump is too rich. i'm betting too rich as manufacturers/rebuilders typicaly build on the rich & safe side vs. lean/go boom side. the shooter nozzle is probably too large. i highly recommend you get a holley education via books or take it to an experienced pro.they are simple carbs but, you can sure mess "em up if your ignorant of the design. also, when setting the idle mixture screws use a vacuum guage & set them for the highest reading.adjust the idle speed as needed to maintain the recommended speed. you'll be happier with 12 deg. initial advance @ idle.

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