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1981 Elcamino 229 v6 timing question

3K views 30 replies 5 participants last post by  Karadjgne 
#1 ·
I am working on my dads' elcamino. It is a 1981 base model with the vin code k, he has taken it to several mechanics with no luck in getting the thing running decent. I took the task upon my self to get this thing going for him. Right away i noticed several things missing that would support the computer controlled carb. The check engine light is also not working, this is not the original motor, most of the vacuum hoses are missing or not hooked up correctly. Long story short, i purchased a non computer controlled carb and currently have it installed and running. My question is the original distributor is a HEI with vacuum advance that has a single wire that connects to the ecm. I understand the next generation has the 4 wire plug but this one does not. What should the base timing be set at and does the advance need to go thru the thermal vacuum port or straight to manifold pressure? According to the Haynes manual timing should be 6* BTDC for the 81 but I'm not sure if the ecm actually controlled the timing or just regulated the carb. That number jumps to 12* for the 1980. any suggestions?
Sean
 
#2 · (Edited)
Two things.
First, fix the vacuum situation, there's nothing you can do to get the motor running right, if there's a vacuum leak.
Second, throw out the books, they won't apply. It's all about the motor, not the car. Since it's not an original motor, there's no assumption on it being the original dizzy. A CCC dizzy is run from the ecm, not vacuum advance.

The 1980 Chevy 229 used a mechanical dualjet, vacuum dizzy, the 81-84 229 was CCC, and differed from the Buick 231 basically by where the dizzy is placed (rear for Chevy, front for Buick) but both were optioned back then, the Buick being a California setup.

So what you have is a poorly slapped together mix of parts. Either go all out CCC or scrap it totally in favor of vacuum.

Vacuum advance will be manifold vacuum, not ported. As far as timing, that's impossible to say unless you can find the engine date code stamp, as you say it can change from year to year, but basically you'll set timing according to manifold vacuum, without the dizzy attached, in the 15-20 range at 500-700rpm. You might adjust that later if getting knock.

Without being able to verify the timing mark location, those can also change, I'd also suggest actually physically/manually verifying TDC beforehand via the piston itself and making sure that when you set the timing by light, it's accurate. Some timing pegs were at 12 o'clock on the timing cover, some were at closer to 1:30-2:00 o'clock and on the block, which can throw off timing by 20+°.
 
#3 ·
Two things.
First, fix the vacuum situation, there's nothing you can do to get the motor running right, if there's a vacuum leak.
Second, throw out the books, they won't apply. It's all about the motor, not the car. Since it's not an original motor, there's no assumption on it being the original dizzy. A CCC dizzy is run from the ecm, not vacuum advance.

The 1980 Chevy 229 used a mechanical dualjet, vacuum dizzy, the 81-84 229 was CCC, and differed from the Buick 231 basically by where the dizzy is placed (rear for Chevy, front for Buick) but both were optioned back then, the Buick being a California setup.

So what you have is a poorly slapped together mix of parts. Either go all out CCC or scrap it totally in favor of vacuum.

Vacuum advance will be manifold vacuum, not ported. As far as timing, that's impossible to say unless you can find the engine date code stamp, as you say it can change from year to year, but basically you'll set timing according to manifold vacuum, without the dizzy attached, in the 15-20 range at 500-700rpm. You might adjust that later if getting knock.

Without being able to verify the timing mark location, those can also change, I'd also suggest actually physically/manually verifying TDC beforehand via the piston itself and making sure that when you set the timing by light, it's accurate. Some timing pegs were at 12 o'clock on the timing cover, some were at closer to 1:30-2:00 o'clock and on the block, which can throw off timing by 20+°.
Thanks for your reply. The CCC wirning harness is there and i still have the carb i removed. The funny thing is when you go to the parts house and look at distributors, the ones for the 1981 model with the vin code K do not have the 4 wires. just one wire coming out of the distributor thru the back side of the cap.
Font Line Parallel Screenshot Gun barrel
 
#8 ·
At this point, you'd spend too much time and money for no real gains. The CCC was setup to be using all the smog equipment, that includes stuff like the map and egr, so it could get comprehensive data to apply to the charts. It'll run with just the map, egr, O² and carb, but if the carb, choke and timing is well setup without using the CCC, you end up with a bunch of less parts to kick the check engine light, is definitely easier to tune and far more customizable.
 
#9 ·
A 1981 used a computer controlled carb and distributer and the distributer had a 4 wire connector that went back to the computer. From your post, your distributer in the car currently has a vacuum advance meaning its a non-computer distributer and the singe wire is a power wire back to the ignition switch. You should be fine with 6-12 degrees advance with the vacuum advance disconnected and non-computer carb assuming no pinging with the EGR and air pump discoed. The vacuum advance should have ported vacuum - meaning only vacuum off idle and above.
 
#10 ·
It runs ok now except at an idle with the ac on it struggles a bit at a stop in gear. There is no throttle kick up to compensate for the additional load of the AC. My dad is 83 and wont drive far in it but i want to make it as smooth and dependable as possible. i have just about all the components and the carb just needs rebuilt. The only part I'm having difficulty finding is the mixture control solenoid. the carb currently has one in it but I'm not sure how to test it. I am pretty handy and have done tons of work on my LS motors and outboards. This technology is just too old for me to know about as I was a child lol.
 
#12 ·
Ok so I have decided to have the CCC carburetor rebuild by Mountain Man as he seems very respected around here. This means i need to get the rest of the system working as well. 1981 system seems to be a little different than the 82 on systems. Does anyone have an engine diagram for the 229 with the vin code k? i cannot seem to locate the map sensor and all the pictures online show a 3 wire connection on the map sensor. The only spots on the harness that I can find are (2) 2 prong plugs for the A.I.R. system and (2) 2 prong plugs on top of the intake (not sure where they go yet). I have looked on the fender wells, firewall and under the dash. Anyone have any insight?
 
#20 ·
So I sent the Carburetor to Mountainman and they did a fantastic job...... no the fun begins! I attempted to get a dwell reading and nothing. Can you use a digital meter for this? The meter claims to read dwell angle but nothing will come up. Also how do you check the ECM to make sure it functions properly? I have replaced the coolant sensor and the O2 sensor and on this model there really isn't any other sensor that would relate. I did check the dwell connection to ground and have 12v there. Any insight would be greatly appreciated.
 
#23 ·
Ok so I finally got this thing running and was able to get a dwell reading, but only if the ecm coolant temp sensor was unplugged. Once the engine warms up it comes out of closed loop, completely backwards lol. The 2 wire connector looks like it needs to be replaced but I cannot find one. All I can find is the single wire connector and now I think this is probably the wrong temp switch as well. This would explain why it goes out of closed loop once it reaches operating temp. Can anyone provide part numbers or a work around?
 
#26 ·
Found it in a couple minutes . It should have been that easy looking for the 10 month old
failed battery receipt.
After over an hour and a half of looking it ended up being in the first place I looked, where
it was 'hiding' since last August.
Anyway, the name of the company is- The Repair Connector Store
Fresno,CA 93720
It's been 6 years since ordering . Hopefully, they're still in business.
Good pricing and quick turnaround.
 
#28 ·
This is the connector I am looking for. I purchased one that i found in the search bar on another post for a Malibu with same year and engine code and it appears to be working. I have gotten the check engine light working and have a code 44- lean. I just replaced the O2 sensor and the mixture control in the carb was replaced by Mountain Man. I have yet to find any vacuum leaks and now I am kind of scratching my head.....
 
#29 ·
Ok, about rebuilt carbs, by anyone including MM, you may (and this applies especially to 4 setting ccc carbs) have to get final settings done on the actual motor. MM can get most of the settings and adjustments back to factory specs, but since each motor is essentially unique and has its own quirks, you may need to make some adjustments.

For instance, the factory specs for the mixture screws are 3⅜ out from lightly seated, but if the air-bleed holes are slightly too large, missing brass inserts have the wrong size brass inserts for the motor etc then to get good vacuum you may need to adjust to 3 turns out or 4 turns out etc. And that is also somewhat dependant on your timing.

Same goes for setting the choke and fast idle cam and choke pull-off, MM can get it in the ballpark, can even get them spot on for many motors, plug and play carb settings, but that's also no guarantee it'll be perfect for your particular motor.
 
#30 ·
Can anyone lead me in the right direction as for setting the Idle Air Bleed Valve..... i have searched for the gauge tool and it appears to no longer be available. I acquired a monitor 95 scan tool and found the new bosh O2 sensor does not appear to be working correctly. I put the old one back in and no longer have the code 44 lean. You could tell it wasn't running lean as when the code would throw it would spit and sputter with black smoke.... obviously running rich from the ecu command. Things are coming together but i just cannot for the life of me get the dwell at or close to 30. It will vary from 40-45 and I can't seem to adjust it out. I would like to find an original AC Declo O2 sensor to replace the old one as the Bosh just didn't work well.
Sean
 
#31 ·
Strangely enough, the Boshe is OEM. Supposedly. But there's many reports by ppl that it's not a good match, maybe that's quality control, who knows.

You don't need a special tool for the air-bleed. Piece of stiff wire, like a metal coat hanger, works just fine. Give the end that goes into the carb a nice smooth finish but the end that touches the air-bleed can be rough cut by a pair of pliers etc.

All you'll need to do is bend it to go from the hole to the bleed screw and make the parallel distance from the tips whatever your measurement requires.

But that is not a fix. That simply puts the screw in the ballpark, even the tool won't and isn't the final fix, that's why the diagnostic port for the dwell. You'll need to move that screw in 'tiny' increments to get the dwell right, regardless of the tool setting.

And that's going to be determined a lot by the lean/rich screw settings of the MCS. It could very well be that the Boshe is working right, but the lean/rich screws are off, which will make the air-bleed screw off and shoot you that 44 code.
 
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