Rotates but not starting - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sully Erna · 05-26-2007, 11:45 AM

my 85 w/ a 305 rotates but does not start up. I took it to chevy and they said I needed a new carb. They wanted $50 installed so I told them I could get it cheaper somewhere else. So I had two carbs rebuilt and I still have the same problem. I decided to check the timing belt and it was about to come of the crank gear. I replaced the timing set and went by the haynes manual for getting tdc. Turn crankshaft until the balancer line is at 0. Look at the rotor and make sure it is pointing to plug #1. Everything looked in time to me. Well I get everything done and all the accessories back on and I tried to crank it up and I still have the same problem. It shoots fire back up through the carb.

It has to be some kind of timing issue but where should I go from here?

Sully Erna · 05-26-2007, 11:47 AM

EDIT: chevy wanted 550

Ivan D. · 05-26-2007, 08:48 PM

how does it rotate? look at yer fan while trying to start up the engine, if it turns then stops then turns again as you have the key in the "start" position yer engine is actually trying to run, but the distributor is off so the cylinders fire at the wrong time - chances are with at least one of the cylinders that happens while the intake valve is open, hence yer backfire through the carb.

magnethead · 05-26-2007, 11:07 PM

Quote:

Originally Posted by Sully Erna

my 85 w/ a 305 rotates but does not start up. I took it to chevy and they said I needed a new carb. They wanted $50 installed so I told them I could get it cheaper somewhere else. So I had two carbs rebuilt and I still have the same problem. I decided to check the timing belt and it was about to come of the crank gear. I replaced the timing set and went by the haynes manual for getting tdc. Turn crankshaft until the balancer line is at 0. Look at the rotor and make sure it is pointing to plug #1. Everything looked in time to me. Well I get everything done and all the accessories back on and I tried to crank it up and I still have the same problem. It shoots fire back up through the carb.

It has to be some kind of timing issue but where should I go from here?

from experience: Don't trust the balancer for knowing where #1's TDC is. My truck has a balancer from a newer block so the TDC mark is about 60 degrees off...We checked it using a small screwdriver and a flywheel turner and painted a yellow line across the balancer with model paint to mark true TDC.

bigblock79 · 05-26-2007, 11:11 PM

you might be a 180 out.

knightlife · 05-27-2007, 01:12 PM

its your firing order... has to do with your distributor brudda.
here:
http://wiki.answers.com/Q/What_is_th...or_a_Chevy_350

Srubydo1986 · 05-27-2007, 02:47 PM

sound like it still 180 degrees off. done it many of times just a thought not an insault.

Ivan D. · 05-27-2007, 02:58 PM

also a Chevy dizzy rotates clockwise, unlike a Ford one - seen people get them messed up, both, it's pretty amusing really (no pun intended)

Sully Erna · 05-28-2007, 12:16 AM

Will a distributor from a 76 350 work? I have a 4 wire hookup that goes into the cab of the truck and the standard BAT and and coil hookup. I have heard that this year dizzy will work but how if the 4 wire hookup is unplugged.
It is a 85 305 H w/ fed. emmissions btw. thanks

Ivan D. · 05-28-2007, 03:51 AM

85, ain't that the computer controlled carb and dizzy? Computer controlled distributors don't have vacuum advance, while the '76 dizzy will have it, and you can run it like most of us run our trucks - problem will be the computer expects some signal from the dizzy, and with the '76 dizzy that just ain't happening. Dunno how the ECM logic is set up, but I'd assume it'll freak out when it don't "see" the dizzy and it'll make the carb act all funky.

magnethead · 05-28-2007, 10:38 AM

Quote:

Originally Posted by Ivan D.

85, ain't that the computer controlled carb and dizzy? Computer controlled distributors don't have vacuum advance, while the '76 dizzy will have it, and you can run it like most of us run our trucks - problem will be the computer expects some signal from the dizzy, and with the '76 dizzy that just ain't happening. Dunno how the ECM logic is set up, but I'd assume it'll freak out when it don't "see" the dizzy and it'll make the carb act all funky.

In which case you say, goodbye computer.

05-26-2007, 11:47 AM	#2
Sully Erna Registered User Join Date: Aug 2006 Location: Dallas Posts: 42	Re: Rotates but not starting EDIT: chevy wanted 550

05-26-2007, 08:48 PM	#3
Ivan D. glamoros piece o' lowlife Join Date: Mar 2007 Location: Redford, MI Posts: 1,164	Re: Rotates but not starting how does it rotate? look at yer fan while trying to start up the engine, if it turns then stops then turns again as you have the key in the "start" position yer engine is actually trying to run, but the distributor is off so the cylinders fire at the wrong time - chances are with at least one of the cylinders that happens while the intake valve is open, hence yer backfire through the carb. __________________ The more I drink, the more I drink, the more I drink... diesel, reg cab, long bed, 4 across the rear, single stack, wooden stakes, and lotsa lights - the Hay Express

05-26-2007, 11:11 PM	#5
bigblock79 67 Chevy Stepside Join Date: Mar 2007 Location: Jonesville NC Posts: 836	Re: Rotates but not starting you might be a 180 out. __________________ 1967 Chevy stepside 1976 BIG DOOLEY 454 turbo 400 4:11

05-27-2007, 01:12 PM	#6
knightlife Dark Heart Motorsports Join Date: Apr 2007 Location: 29404 DKFX Posts: 683	Re: Rotates but not starting its your firing order... has to do with your distributor brudda. here: http://wiki.answers.com/Q/What_is_th...or_a_Chevy_350 __________________ How Deep Can YOU Bleed..? 1985 Chevy Blazer K5- 6.2 N/A, 400 turbo trans CUCV, 12v converted... a new chapter 2005 GMC Sierra Crew Cab 6.0 powwwaa!!! custom jumpseat install w/ captain seats, Hypertech tuner, MSD Blaster Coils, CB and twin antenna's, all electric interior, touch screen in dash. custom center console, with jump seat replacing original console. 1500 HD!

05-27-2007, 02:47 PM	#7
Srubydo1986 The Crazy Machanic Join Date: Jan 2007 Location: Nokesville Va Posts: 1,437	Re: Rotates but not starting sound like it still 180 degrees off. done it many of times just a thought not an insault. __________________ 1986 Sliverado longbed 400 small block mean as hell, 700r4 trans (5 speed coming one day) 1970 chevelle 2dr sedan Latest update June 24 2007. 1957 4 door stationwagon - pink all original needing a good restore (body great, floors bad) newest additions 1965 shortbed fleet great granddads. Been told im nuts to bring it back from the dead (still going to happen) plans-all stock with a turbo 292 inline 3 speed column shift. and thats it big block 427 and 5 speed trans and ford 9 inch theyhave no home yet thinking what to put them in and a 79 c60 trash truck um no idea i have one Last edited by Srubydo1986; 05-27-2007 at 02:47 PM.*

05-26-2007, 11:45 AM	#1
Sully Erna Registered User Join Date: Aug 2006 Location: Dallas Posts: 42	Rotates but not starting my 85 w/ a 305 rotates but does not start up. I took it to chevy and they said I needed a new carb. They wanted $50 installed so I told them I could get it cheaper somewhere else. So I had two carbs rebuilt and I still have the same problem. I decided to check the timing belt and it was about to come of the crank gear. I replaced the timing set and went by the haynes manual for getting tdc. Turn crankshaft until the balancer line is at 0. Look at the rotor and make sure it is pointing to plug #1. Everything looked in time to me. Well I get everything done and all the accessories back on and I tried to crank it up and I still have the same problem. It shoots fire back up through the carb. It has to be some kind of timing issue but where should I go from here?

05-27-2007, 02:58 PM	#8
Ivan D. glamoros piece o' lowlife Join Date: Mar 2007 Location: Redford, MI Posts: 1,164	Re: Rotates but not starting also a Chevy dizzy rotates clockwise, unlike a Ford one - seen people get them messed up, both, it's pretty amusing really (no pun intended) __________________ The more I drink, the more I drink, the more I drink... diesel, reg cab, long bed, 4 across the rear, single stack, wooden stakes, and lotsa lights - the Hay Express

05-28-2007, 12:16 AM	#9
Sully Erna Registered User Join Date: Aug 2006 Location: Dallas Posts: 42	Re: Rotates but not starting Will a distributor from a 76 350 work? I have a 4 wire hookup that goes into the cab of the truck and the standard BAT and and coil hookup. I have heard that this year dizzy will work but how if the 4 wire hookup is unplugged. It is a 85 305 H w/ fed. emmissions btw. thanks

05-28-2007, 03:51 AM	#10
Ivan D. glamoros piece o' lowlife Join Date: Mar 2007 Location: Redford, MI Posts: 1,164	Re: Rotates but not starting 85, ain't that the computer controlled carb and dizzy? Computer controlled distributors don't have vacuum advance, while the '76 dizzy will have it, and you can run it like most of us run our trucks - problem will be the computer expects some signal from the dizzy, and with the '76 dizzy that just ain't happening. Dunno how the ECM logic is set up, but I'd assume it'll freak out when it don't "see" the dizzy and it'll make the carb act all funky. __________________ The more I drink, the more I drink, the more I drink... diesel, reg cab, long bed, 4 across the rear, single stack, wooden stakes, and lotsa lights - the Hay Express



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