1981 El Camino

Update your progress on your various car projects.

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Maverick
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Re: 1981 El Camino

Post by Maverick »

Still in search of bracket(s) to mount the cruise control servo. This is the non-cruise throttle cable bracket currently on the Edelbrock manifold, where it only used one carb mount stud. To stabilize it, I added a piece tacked on to the bracket and also bolted to the intake.
Cruise Bracket.png
Maverick
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Maverick
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Re: 1981 El Camino

Post by Maverick »

After searching unsuccessfully for a second bracket that would stabilize the one servo bracket I have, I decided to improvise. Bent one end of a 1/4" steel rod 90*, threaded the bent end to screw into the welded-on nut on the bracket, threaded the other end, drilled a 9/32" hole in the throttle bracket end to receive the rod, and the bracket is secured.
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1029171824.jpg
Everything lines up nicely EXCEPT, at full throttle the servo is being pushed. There's a slot in the rod end that I'm sure is supposed to allow the throttle to be fully opened without pushing on the servo.
1029171826.jpg
Looks like I'll have to enlarge a hole on the carb throttle lever to mount the rod end with a shorter radius and less throw. Maybe first I'll get the transducer installed and wired, run the vacuum lines and see if it all works.
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ttamrettus
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Re: 1981 El Camino

Post by ttamrettus »

I was going to send you mine but my 79 doesn't have cruise.
Matt Sutter
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Maverick
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Re: 1981 El Camino

Post by Maverick »

Thanks for the thought but I don't know if it would have worked anyway. The '81 was the first year where the "Resume" function was included. Fortunately, the transducer I acquired has the Resume function and the wiring that came with it matches the wiring for the cruise controls on the turn signal lever. I'm eager to know if it all works.
Maverick
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Maverick
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Re: 1981 El Camino

Post by Maverick »

Everything lines up nicely EXCEPT, at full throttle the servo is being pushed. There's a slot in the rod end that I'm sure is supposed to allow the throttle to be fully opened without pushing on the servo.
Holley sells this stud to mount both the throttle cable and the cruise control rod on the same hole in the throttle lever.

https://www.amazon.com/Holley-20-36-Car ... lley+20-36

That will shorten the pull for the cruise rod. Ordered from Amazon.
Maverick
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Maverick
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Re: 1981 El Camino

Post by Maverick »

Got the cruise transducer mounted, wired and vacuum lines connected. Put it up on jack stands in the garage to test it. Cruise was functioning :) but with binary (well, not quite) throttle control. :( RPMs bounced between 10K and 20K.

Thought maybe throttle control would function better with a load so took it for a test drive. Still surges too much to be useful. Maybe too much slack in the pull chain?
1104171508_Burst01.jpg
Surely it has to have some slack. I'll have to see what diagnostic info is available in the shop manual and on the Internet.
Maverick
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Maverick
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Re: 1981 El Camino

Post by Maverick »

Removing the slack in the pull chain helped but the cruise is still too aggressive -- the set speed is exceeded then it backs off too much. Vacuum lines all look good so not sure where to go from here. I could put a stronger throttle spring on it if that would help. Wonder if a vacuum reservoir/check valve, with consistent vacuum, would help. I'm hesitant to shorten the stock pull rod but it might provide less play than the rigged pull chain.
Maverick
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Maverick
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Re: 1981 El Camino

Post by Maverick »

Got another original pull for the servo from a guy on the EC forum. It's 1/4" shorter than the one I had.
1114171740.jpg
That turns out to be the right length so no shortening of a rod is necessary.

Cruise is now almost usable.

But, now there's a noticeable hesitation in the engine which might be contributing to the remaining surging. :( Hope I don't have to redo a bunch of tuning now that the cruise vacuum is hooked up. Tested the cruise vacuum system leak down by attaching a vacuum pump to the hose that supplies manifold vacuum to the transducer. It leaks down from 10 to 5 in Hg in about 10 seconds. No idea if that's normal.

Also noticed that the vacuum hose connected to the servo is a little loose. Put a hose clam on it. I'll get it warmed up well, readjust the idle mixture screws, and see if hesitation and cruise surging are cured.
Maverick
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5th Gen Door Window Install/Adjustment

Post by Maverick »

I did some adjustments when the window felts were replaced in the driver's door but result isn't perfect. Maybe I'll try again some day. Or, replace the felts in the passenger door.

http://www.elcaminocentral.com/showthread.php?t=49658
Maverick
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Re: 1981 El Camino

Post by Maverick »

It's gone. Delivered it to the buyer South of Raleigh this morning. Transfer was painless -- there is a branch of my credit union a couple of miles from his house. Got and deposited the cash and signed the title over to him using the CR notary. It ran well on the way.

The buyer is going to surprise his dad with a gift of the EC. What a guy!!

There was a second buyer that wanted the EC BAD! Even when I told him I was holding it till today for the buyer, he came with a car trailer to look at it. He called again this morning to see if the deal was falling thru. I gave the buyer the name and phone number of the second guy in case his father decides he doesn't want it.
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Basement Paul
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Re: 1981 El Camino

Post by Basement Paul »

Sorry to see it go, it was cool. I like the story of the guy buying it for his dad though. Real cool!

-BP
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