Engine Lag - Need Help! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

geoman · 12-06-2007, 08:28 PM

Guys,

On my 67 C-10, when I go to start the engine, it will turn over fine for the first four or five revolutions and then for some reason it will lag really slow that point on. Sometimes it will fire, sometimes it wont. The p.o. hacked the ignition switch and it is push button start. Turn the key and hit the button. Go figure.

I noticed the negative battery cable and the starter solinoid was really warm.

It has a brand new starter from the previous owner. It has been converted to HEI and I have put new plugs, cap, rotor, 925 cca battery, plugs, etc.

It is a 350 that has been rebuilt but the inside specs I am unsure of but it is cammed up but has smogger 882 heads..Again, go figure. It is running REALLY rich right now on the passenger bank (so much it is slightly smoking on that side and will BURN the heck out of your eyes ). Its not oil burn. It also has a rebuilt 600 eddy carb and intake.

I am lost as to what to do next.

Help!

Mike

**68 Stepside** · 12-06-2007, 08:37 PM

I know squat about timing and such, but it sounds like a timing issue to me. Firing too early maybe?

496stroker1 · 12-06-2007, 11:03 PM

you said your battery cables are warm, maybe your starter needs shims. i have a 454 when i tried starting it turned slowly and battery cables got warm cuz the starter was way too close to the flexplate and workin overtime to turn the engine over. shimmed it and all was well

Blazer1970 · 12-07-2007, 06:43 AM

It sounds like maybe the vacuum advance is kicking in after the engine starts spinning which is advancing the timing too much. Try starting it with the vacuum line to the distributor disconnected.

68C15 · 12-07-2007, 06:52 AM

4 to 5 revolutions?! it doesn't kick off on the first one?

geoman · 12-07-2007, 07:29 AM

I shimmed the starter as it was way too far from the flexplate and it is a lot better.. the flexplate looks fine as well.

I will try the vacuum advance trick.

At times it does kick over on the first or second try but most of the time it doesnt and will start to lag.

I am going to try these things first and then if nothing works, then I am going to pull the cap back off and reset the timing to TDC.

68C15 · 12-07-2007, 09:26 PM

FWIW a weak or cracked magnet in the dist. shaft will cause a long crank. it takes a while for it to build up enough field in the pick up coil.

12-06-2007, 08:28 PM	#1
geoman Registered User Join Date: Oct 2007 Location: Brandon, FL Posts: 335	Engine Lag - Need Help! Guys, On my 67 C-10, when I go to start the engine, it will turn over fine for the first four or five revolutions and then for some reason it will lag really slow that point on. Sometimes it will fire, sometimes it wont. The p.o. hacked the ignition switch and it is push button start. Turn the key and hit the button. Go figure. I noticed the negative battery cable and the starter solinoid was really warm. It has a brand new starter from the previous owner. It has been converted to HEI and I have put new plugs, cap, rotor, 925 cca battery, plugs, etc. It is a 350 that has been rebuilt but the inside specs I am unsure of but it is cammed up but has smogger 882 heads..Again, go figure. It is running REALLY rich right now on the passenger bank (so much it is slightly smoking on that side and will BURN the heck out of your eyes ). Its not oil burn. It also has a rebuilt 600 eddy carb and intake. I am lost as to what to do next. Help! Mike __________________ 1967 Fleetside, Sanford and Son Special Ivory/Blue Vinyl, 350/TH-400/12-bolt

12-06-2007, 08:37 PM	#2
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,690	Re: Engine Lag - Need Help! I know squat about timing and such, but it sounds like a timing issue to me. Firing too early maybe? __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

12-06-2007, 11:03 PM	#3
496stroker1 Registered User Join Date: Nov 2007 Location: brooks alberta Posts: 65	Re: Engine Lag - Need Help! you said your battery cables are warm, maybe your starter needs shims. i have a 454 when i tried starting it turned slowly and battery cables got warm cuz the starter was way too close to the flexplate and workin overtime to turn the engine over. shimmed it and all was well

12-07-2007, 06:43 AM	#4
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,507	Re: Engine Lag - Need Help! It sounds like maybe the vacuum advance is kicking in after the engine starts spinning which is advancing the timing too much. Try starting it with the vacuum line to the distributor disconnected. __________________ Tim

12-07-2007, 06:52 AM	#5
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: Engine Lag - Need Help! 4 to 5 revolutions?! it doesn't kick off on the first one?

12-07-2007, 07:29 AM	#6
geoman Registered User Join Date: Oct 2007 Location: Brandon, FL Posts: 335	Re: Engine Lag - Need Help! I shimmed the starter as it was way too far from the flexplate and it is a lot better.. the flexplate looks fine as well. I will try the vacuum advance trick. At times it does kick over on the first or second try but most of the time it doesnt and will start to lag. I am going to try these things first and then if nothing works, then I am going to pull the cap back off and reset the timing to TDC. __________________ 1967 Fleetside, Sanford and Son Special Ivory/Blue Vinyl, 350/TH-400/12-bolt

12-07-2007, 09:26 PM	#7
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: Engine Lag - Need Help! FWIW a weak or cracked magnet in the dist. shaft will cause a long crank. it takes a while for it to build up enough field in the pick up coil.



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