Changed carb, still having issues, diagnostics? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

toolboxchev · 09-16-2015, 01:34 PM

Second that on the vacuum check.

Also a vacuum gauge will not detect a leaking brake booster sometimes. Last time I went through this it was the Ignition Module in the HEI distributor and the brake booster.

choctawchevyclassics · 09-16-2015, 01:51 PM

Quote:

Originally Posted by toolboxchev

Second that on the vacuum check.

Also a vacuum gauge will not detect a leaking brake booster sometimes. Last time I went through this it was the Ignition Module in the HEI distributor and the brake booster.

Not sure why it wouldn't detect a vacuum brake booster, unless it has something to do with the check valve.

choctawchevyclassics · 09-16-2015, 01:52 PM

OH!!! And by the way!!!Vacuum Sucks!!!

Just sayin!!!

Mike C · 09-16-2015, 05:19 PM

There's an old hot rodders adage that says 90% of carburetor problems are ignition. I'd go through that system completely then start back with carb.

Black smoke out the exhaust is typically too rich but a backfire out the carb is typically a lean response. Therefore my "internets diagnostics" says you have ignition problems.

If you haven't already, great time to upgrade to HEI and high performance spiral wrapped suppression plug wires.

cleszkie · 09-16-2015, 07:16 PM

Make sure your plug wires are routed correctly. Getting two mixed up will mimick a timing problem. Check the simple, obvious things first.

09-16-2015, 01:34 PM	#1
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Changed carb, still having issues, diagnostics? Second that on the vacuum check. Also a vacuum gauge will not detect a leaking brake booster sometimes. Last time I went through this it was the Ignition Module in the HEI distributor and the brake booster.

09-16-2015, 01:52 PM	#3
choctawchevyclassics Registered User Join Date: Feb 2009 Location: Choctaw, Ok Posts: 184	Re: Changed carb, still having issues, diagnostics? OH!!! And by the way!!!Vacuum Sucks!!! Just sayin!!! __________________ choctawchevyclassics

09-16-2015, 05:19 PM	#4
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,740	Re: Changed carb, still having issues, diagnostics? There's an old hot rodders adage that says 90% of carburetor problems are ignition. I'd go through that system completely then start back with carb. Black smoke out the exhaust is typically too rich but a backfire out the carb is typically a lean response. Therefore my "internets diagnostics" says you have ignition problems. If you haven't already, great time to upgrade to HEI and high performance spiral wrapped suppression plug wires. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

09-16-2015, 07:16 PM	#5
cleszkie Registered User Join Date: Feb 2003 Location: Santa Ana, CA Posts: 2,191	Re: Changed carb, still having issues, diagnostics? Make sure your plug wires are routed correctly. Getting two mixed up will mimick a timing problem. Check the simple, obvious things first.



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