Shifting later after installing HEI??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MrClean · 11-19-2010, 04:34 PM

So I fixed one thing and break another!

I installed a new HEI distributor last night along with plugs and wires to replace my old points distributor. (THANKS ED!)
On the way home it was shifting really late, almost seemed like it wasn't going to shift at all.
Did I bump something during the install?
Does the new HEI have anythink to do with it?
What should I look at?

Engine runs nice now and idles at a lower RPM.
This is on a 72 c10 with 350 motor and transmission.

NovaOne · 11-19-2010, 04:39 PM

Sounds like maybe the vacuum line that goes to the trans came loose. It should be connected to intake vacuum.

MrClean · 11-19-2010, 04:52 PM

forgot to mention that this was my first over 60 mph drive in this truck, 21 miles to the base and 21 miles back home, if that matters...

NovaOne: i'll check the vacuum line when I get home. Thanks!

71swb4x4 · 11-19-2010, 05:44 PM

When I read the title my first thought was vacuum line. That would be the first place to look.

**Palf70Step** · 11-19-2010, 06:42 PM

I am with the others, the vacuum line was my first thought.

MrClean · 11-20-2010, 05:39 PM

Thanks guys you were right!
Does this mean my timing is off since this vacuum line was disconnected?
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**Palf70Step** · 11-20-2010, 07:10 PM

It would not hurt to recheck it. You did have a vacuum leake while you were timing it.

LONGHAIR · 11-20-2010, 07:36 PM

The distributor should be disconnected from the vacuum while the timing light is on, but you have to be sure to plug the port where it was connected. Re-connect the transmission line, which will stop that leak, and re-check the timing.

MrClean · 12-09-2010, 11:23 AM

haven't had the time to check the timing yet, but will be doing it this weekend.
Thanks

slikside · 12-09-2010, 10:13 PM

MrClean, one question for you. did you have to modify that transmission vacuum line at all to get your HEI dizzy in? I will be doing the HEI upgrade in the near future on the same basic truck/engine, and I can tell that line will have to bent out some to allow the wider diameter dizzy to fit well. Just wonder'n if that was an issue for you?

MrClean · 12-10-2010, 12:36 AM

Slikside: I had to unplug the vacuum line then drop in the dizzy then plug it back in. Forgot that last part...
Had to reshape the line just a bit, and added a clamp on the hose to keep it from falling off.
Posted via Mobile Device

slikside · 12-11-2010, 12:01 AM

OK, good to know. Thanks MrClean. Glad you found that disconnected line. Sure is nice when you find the easy fix that makes all the difference.

11-19-2010, 04:34 PM	#1
MrClean I'LL TRY TO FIX IT! Join Date: Oct 2007 Location: Santa Maria, CA Posts: 108	Shifting later after installing HEI??? So I fixed one thing and break another! I installed a new HEI distributor last night along with plugs and wires to replace my old points distributor. (THANKS ED!) On the way home it was shifting really late, almost seemed like it wasn't going to shift at all. Did I bump something during the install? Does the new HEI have anythink to do with it? What should I look at? Engine runs nice now and idles at a lower RPM. This is on a 72 c10 with 350 motor and transmission. __________________ -- Jorge -- 1972 Custom/10 LWB 350 My Build Last edited by MrClean; 11-19-2010 at 04:53 PM.

11-19-2010, 04:39 PM	#2
NovaOne Registered User Join Date: Oct 2010 Location: Seattle WA Posts: 21	Re: Shifting later after installing HEI??? Sounds like maybe the vacuum line that goes to the trans came loose. It should be connected to intake vacuum.

11-19-2010, 04:52 PM	#3
MrClean I'LL TRY TO FIX IT! Join Date: Oct 2007 Location: Santa Maria, CA Posts: 108	Re: Shifting later after installing HEI??? forgot to mention that this was my first over 60 mph drive in this truck, 21 miles to the base and 21 miles back home, if that matters... NovaOne: i'll check the vacuum line when I get home. Thanks! __________________ -- Jorge -- 1972 Custom/10 LWB 350 My Build

11-19-2010, 05:44 PM	#4
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	Re: Shifting later after installing HEI??? When I read the title my first thought was vacuum line. That would be the first place to look. __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

11-19-2010, 06:42 PM	#5
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,083	Re: Shifting later after installing HEI??? I am with the others, the vacuum line was my first thought. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

11-20-2010, 05:39 PM	#6
MrClean I'LL TRY TO FIX IT! Join Date: Oct 2007 Location: Santa Maria, CA Posts: 108	Re: Shifting later after installing HEI??? Thanks guys you were right! Does this mean my timing is off since this vacuum line was disconnected? __________________ -- Jorge -- 1972 Custom/10 LWB 350 My Build

11-20-2010, 07:10 PM	#7
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,083	Re: Shifting later after installing HEI??? It would not hurt to recheck it. You did have a vacuum leake while you were timing it. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God! Last edited by Palf70Step; 11-20-2010 at 07:11 PM.

12-09-2010, 11:23 AM	#9
MrClean I'LL TRY TO FIX IT! Join Date: Oct 2007 Location: Santa Maria, CA Posts: 108	Re: Shifting later after installing HEI??? haven't had the time to check the timing yet, but will be doing it this weekend. Thanks __________________ -- Jorge -- 1972 Custom/10 LWB 350 My Build

12-09-2010, 10:13 PM	#10
slikside Registered User Join Date: Jun 2010 Location: San Diego Co. Posts: 1,176	Re: Shifting later after installing HEI??? MrClean, one question for you. did you have to modify that transmission vacuum line at all to get your HEI dizzy in? I will be doing the HEI upgrade in the near future on the same basic truck/engine, and I can tell that line will have to bent out some to allow the wider diameter dizzy to fit well. Just wonder'n if that was an issue for you?

12-10-2010, 12:36 AM	#11
MrClean I'LL TRY TO FIX IT! Join Date: Oct 2007 Location: Santa Maria, CA Posts: 108	Re: Shifting later after installing HEI??? Slikside: I had to unplug the vacuum line then drop in the dizzy then plug it back in. Forgot that last part... Had to reshape the line just a bit, and added a clamp on the hose to keep it from falling off. Posted via Mobile Device __________________ -- Jorge -- 1972 Custom/10 LWB 350 My Build

12-11-2010, 12:01 AM	#12
slikside Registered User Join Date: Jun 2010 Location: San Diego Co. Posts: 1,176	Re: Shifting later after installing HEI??? OK, good to know. Thanks MrClean. Glad you found that disconnected line. Sure is nice when you find the easy fix that makes all the difference.



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