1993 Topkick: convert tbi/governor? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Chevy454** · 01-17-2010, 06:52 PM

I've got a '93 Topkick with a BBC 366 and the allison automatic, and it has a funky gear driven governor, that has apparently quit...no throttle response at all, and a buddy of mine fiddled with it for a couple houes checking connections and such and it appears the electronics in the governor have quit.
So, does anyone know what part(s) i need to be looking for to convert the tbi over to a governor-less setup? we desperately need to get our dump truck back on the road!

ChevLoRay · 01-17-2010, 11:54 PM

Since your truck is OBDI, a scan tool may be what is needed to help. If there is a way to disable the governor, that would be a good thing. Whether or not it can be done, I don't know.

I drive an '03 Bluebird with a high torque Cummins and an Allison 5-speed. If it has a governor, I've never hit it. But, since it is a school bus, and I drive it according to the laws which limit us to 65MPH....except for rare occasions when passing a big truck or trying to avoid becoming a bottleneck in traffic. It has seen "over 70" when it was just me in it. But, I don't know what the upper limit is on the engine revs. It will go around 25-2700....so, maybe that is the limit. Kinda hard to push a box that is 8 ft wide, 10.5 ft high and 40 ft long to the rev limit in 5th gear.

**Chevy454** · 01-18-2010, 04:15 PM

I think it's a hard part failure, unfortunately? The cable moves freely, as does the linkage within the governor part, but apparently the solenoid on the side engages/disengages something within the tbi housing itself...I tried jumping wires, tried figuring out a way to bypass it (the governor is built into the tbi housing itself), and even kicked around throwing a carb on it...but I'd really like to just find a non-governed tbi that would be a bolt on? The guys @ the feed store (who also run TopKicks/Kodiaks) told me they're out there, and it used to be common, but that's now 15+ year old technology.

**Bob B.** · 01-21-2010, 05:49 AM

Those governor equiped TBI units were used on 366's and 427's up to 1998. Shouldn't be too tough to find one, and that would probably be easier than trying to use a non-governor pickup TBI unit. Having a governor on a medium duty truck is not a bad idea, even with an automatic transmission. Scan it for codes just to be sure you don't have a sensor problem first.

70clone · 04-29-2017, 01:52 AM

I know this thread is old having the same problem

RanchTruck · 02-14-2018, 11:08 PM

I know this is an old thread, but figured I'd pass on how to bypass the governor on these old TBI medium duty trucks. Right in front of the throttle shaft lever/pully there's an electric motor sticking out of the side of the throttle body. 4 T-20 torx screws hold it on. Unplug the motor, take out the screws, finagle it out of the hole and toss it in the trash. Full manual throttle control restored.

Tom · 02-15-2018, 01:48 PM

Hey, a old thread dug up for a good reason!

01-17-2010, 06:52 PM	#1
Chevy454 Registered User Join Date: Dec 1999 Location: Alton, MO Posts: 145	1993 Topkick: convert tbi/governor? I've got a '93 Topkick with a BBC 366 and the allison automatic, and it has a funky gear driven governor, that has apparently quit...no throttle response at all, and a buddy of mine fiddled with it for a couple houes checking connections and such and it appears the electronics in the governor have quit. So, does anyone know what part(s) i need to be looking for to convert the tbi over to a governor-less setup? we desperately need to get our dump truck back on the road! __________________ '72 Super Custom Suburban - 402/400, original bucket seats, 3rd seat, rear air, tilt A few Yenko cars Interested in COPOs, Yenkos or other dealer built muscle cars then go here:www.yenko.net

01-17-2010, 11:54 PM	#2
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: 1993 Topkick: convert tbi/governor? Since your truck is OBDI, a scan tool may be what is needed to help. If there is a way to disable the governor, that would be a good thing. Whether or not it can be done, I don't know. I drive an '03 Bluebird with a high torque Cummins and an Allison 5-speed. If it has a governor, I've never hit it. But, since it is a school bus, and I drive it according to the laws which limit us to 65MPH....except for rare occasions when passing a big truck or trying to avoid becoming a bottleneck in traffic. It has seen "over 70" when it was just me in it. But, I don't know what the upper limit is on the engine revs. It will go around 25-2700....so, maybe that is the limit. Kinda hard to push a box that is 8 ft wide, 10.5 ft high and 40 ft long to the rev limit in 5th gear. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

01-18-2010, 04:15 PM	#3
Chevy454 Registered User Join Date: Dec 1999 Location: Alton, MO Posts: 145	Re: 1993 Topkick: convert tbi/governor? I think it's a hard part failure, unfortunately? The cable moves freely, as does the linkage within the governor part, but apparently the solenoid on the side engages/disengages something within the tbi housing itself...I tried jumping wires, tried figuring out a way to bypass it (the governor is built into the tbi housing itself), and even kicked around throwing a carb on it...but I'd really like to just find a non-governed tbi that would be a bolt on? The guys @ the feed store (who also run TopKicks/Kodiaks) told me they're out there, and it used to be common, but that's now 15+ year old technology. __________________ '72 Super Custom Suburban - 402/400, original bucket seats, 3rd seat, rear air, tilt A few Yenko cars Interested in COPOs, Yenkos or other dealer built muscle cars then go here:www.yenko.net

01-21-2010, 05:49 AM	#4
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,350	Re: 1993 Topkick: convert tbi/governor? Those governor equiped TBI units were used on 366's and 427's up to 1998. Shouldn't be too tough to find one, and that would probably be easier than trying to use a non-governor pickup TBI unit. Having a governor on a medium duty truck is not a bad idea, even with an automatic transmission. Scan it for codes just to be sure you don't have a sensor problem first. __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

04-29-2017, 01:52 AM	#5
70clone Registered User Join Date: Oct 2006 Location: JACKSONVILLE FL Posts: 200	Re: 1993 Topkick: convert tbi/governor? I know this thread is old having the same problem

02-14-2018, 11:08 PM	#6
RanchTruck Registered User Join Date: Dec 2010 Location: NH or WY Posts: 33	Re: 1993 Topkick: convert tbi/governor? I know this is an old thread, but figured I'd pass on how to bypass the governor on these old TBI medium duty trucks. Right in front of the throttle shaft lever/pully there's an electric motor sticking out of the side of the throttle body. 4 T-20 torx screws hold it on. Unplug the motor, take out the screws, finagle it out of the hole and toss it in the trash. Full manual throttle control restored.

02-15-2018, 01:48 PM	#7
Tom driving is in my blood Join Date: Dec 1999 Location: Mesa AZ Posts: 5,739	Re: 1993 Topkick: convert tbi/governor? Hey, a old thread dug up for a good reason! __________________ -78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me.



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