btolenti
1/2 ton status
Re: If your mid 80\'s truck hesitates...
but I have no knock sensor!
but I have no knock sensor!
CK5
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If your mid 80's truck hesitates...
- Thread starter BlazerWheels
- Start date
Re: If your mid 80\'s truck hesitates...
If you have a CCC system, you have (or should have) a knock sensor stock. There's been one in Chev engine CCC systems since 1981 AFAIK. Passenger side, a little above and forward of the starter. Looks like a mushroom.
If you have a CCC system, you have (or should have) a knock sensor stock. There's been one in Chev engine CCC systems since 1981 AFAIK. Passenger side, a little above and forward of the starter. Looks like a mushroom.
btolenti
1/2 ton status
Re: If your mid 80\'s truck hesitates...
no, I checked both sides.....and they both have plugs in them, not sensors. I think CA ones didn't come with ESC....maybe... Either that or it is mounted somewhere else.
no, I checked both sides.....and they both have plugs in them, not sensors. I think CA ones didn't come with ESC....maybe... Either that or it is mounted somewhere else.
Re: If your mid 80\'s truck hesitates...
Can't comment any further, don't have any GM literature here to prove either way.
In any case, would be silly for GM to use a completely computer controlled distributor system without using a knock sensor. Like I said though, I can't be certain of that without seeing a wiring manual for your year. But for an '86, the year before TBI, which certainly does use a knock sensor, it seems unlikely one wasn't used.
I don't *think* the ESC module was seperate on the CCC vehicles, it was all in the ECM, but I could be mistaken. Never really knew what was what until I started this TPI project, and the ESC module IS seperate, and mounted in the engine bay.
Can't comment any further, don't have any GM literature here to prove either way.
In any case, would be silly for GM to use a completely computer controlled distributor system without using a knock sensor. Like I said though, I can't be certain of that without seeing a wiring manual for your year. But for an '86, the year before TBI, which certainly does use a knock sensor, it seems unlikely one wasn't used.
I don't *think* the ESC module was seperate on the CCC vehicles, it was all in the ECM, but I could be mistaken. Never really knew what was what until I started this TPI project, and the ESC module IS seperate, and mounted in the engine bay.
Re: If your mid 80\'s truck hesitates...
I have a cali K5 thats an 85' and it had the ESC and CCC. It was all tied in together. I also have a check engine light and and ECM fuse spot with a fuse in it.
I have a cali K5 thats an 85' and it had the ESC and CCC. It was all tied in together. I also have a check engine light and and ECM fuse spot with a fuse in it.
btolenti
1/2 ton status
Re: If your mid 80\'s truck hesitates...
where else might a knock sensor be mounted?
where else might a knock sensor be mounted?
84_Chevy_K10
Banned
Re: If your mid 80\'s truck hesitates...
[ QUOTE ]
That's because those 9.2:1 305's used terrible heads and 87 octane, and the only way to make sure the engine didn't come back under warranty was to ensure it couldn't kill itself. IE advance retard via a computer.
Don't know if any Federal 350's got the ESC setup or not, but AFAIK, no 350 had that high compression.
[/ QUOTE ]
My old 305 had an aftermarket torque cam, tons of timing via 10-12 initial and vacuum can, and it NEVER knocked. Something about running the right head gaskets and not running too lean, I recall. It's emissions that forced them to run that lean, which is why ESC became a necessity between the compression and the metering.
[ QUOTE ]
That's because those 9.2:1 305's used terrible heads and 87 octane, and the only way to make sure the engine didn't come back under warranty was to ensure it couldn't kill itself. IE advance retard via a computer.
Don't know if any Federal 350's got the ESC setup or not, but AFAIK, no 350 had that high compression.
[/ QUOTE ]
My old 305 had an aftermarket torque cam, tons of timing via 10-12 initial and vacuum can, and it NEVER knocked. Something about running the right head gaskets and not running too lean, I recall. It's emissions that forced them to run that lean, which is why ESC became a necessity between the compression and the metering.
Re: If your mid 80\'s truck hesitates...
Yes, the 305's run pretty lean, ESPECIALLY at cruise.
Most people yank off the EGR, unfortunately the carbs are calibrated to work at cruise with a "lean" mix (expecting the false fill of the cylidner via EGR) and thus removing EGR in many cases, while changing nothing else, results in "pinging".
Just went through this on a buddies truck, and did it on an older motor of mine that EGR wasn't present on. Both times slightly enriching the mix at cruise solved the problem. (pinging in one at 60mph+, surging at 35mph in the other)
Really don't understand why they started out that early with 9.2:1, at the time I don't think the "HP wars" had started back up. As I recall, GM had plans to scrap the 350 in favor of 305's across the board, perhaps those were early attempts to get the same power (or as close as possible) as the 350's.
Not saying the high compression is a bad thing, just too bad they didn't do it with better heads and a 350. /forums/images/graemlins/smile.gif
Yes, the 305's run pretty lean, ESPECIALLY at cruise.
Most people yank off the EGR, unfortunately the carbs are calibrated to work at cruise with a "lean" mix (expecting the false fill of the cylidner via EGR) and thus removing EGR in many cases, while changing nothing else, results in "pinging".
Just went through this on a buddies truck, and did it on an older motor of mine that EGR wasn't present on. Both times slightly enriching the mix at cruise solved the problem. (pinging in one at 60mph+, surging at 35mph in the other)
Really don't understand why they started out that early with 9.2:1, at the time I don't think the "HP wars" had started back up. As I recall, GM had plans to scrap the 350 in favor of 305's across the board, perhaps those were early attempts to get the same power (or as close as possible) as the 350's.
Not saying the high compression is a bad thing, just too bad they didn't do it with better heads and a 350. /forums/images/graemlins/smile.gif
