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Proper procedure for setting the timing on 84

elkabong

Well-known member
Joined
Oct 23, 2002
Messages
225
Location
Chandler, AZ
Corvette
1984 Red Coupe.
What is the proper procedure for adjusting the timing for a 84 350 cfi? I got out my timing light and saw that the timing was way advanced. This why I was having pinging on acceleration. Now when I set it to 8 BTDC (It should be 6 but close enough) it falls on its face and backfires. What in the h.. am I doing wrong. Back in the day all I needed to do was loosen the distributor and block off the vac advance and adjust to my hearts content. I would imagine I am doing or not doing something fairly simple. And I would probably slap my forehead after the response.
 
One other item. I know the gas in the tank is having problems because the car sat for 4 years and I have already been through a fuel filter in about 60 mi. Is it possible it is fuel related and not ignition?
 
Have you disconnected the brown wire prior to timing? A single wire with connector on the driver side ,near firewall by distributor.

Carlo
 
Disconnect this

est.jpg
 
This is what I have. I don't see the brown wire or the thingy in the image.



a.jpg


b.jpg
 
It's there. On my 82 CFI it was near the dist penetrating the firewall. Look for a single wire with connector. It's probably the only single wire in the area, most others are part of a harness. From what i remember it's a brown wire possibly with a trace color. You may have to dig down a little to find it.
Good Luck

Carlo
 
I found it. It had electrical tape wrapped around it. The check engine light came on so I figured it was the right one. I set the timing to 8 BTDC and so far the pinging is gone. Now I know how to set the timing. Thanks.

What does this mysterious wire do?
 
It's the electronic equivalent of "blocking off the vacuum advance" that you mentioned. Technically it called the EST Bypass (Electronic Spark Timing).

Bill
 
Thanks. I did not know that I needed a Phd in Corvette to work on these things. Ah the good 'ol days. :)
 
It figures. Years ago I had a '65 Goat with a 389 and a 6-pack. It was a pleasure and simple to work on and I got to a point where I could replace the clutch in 1 1/2 hours by myself. If I needed to adjust the timing I would pull over to the side of the road, get out my handy dandy 9/16s loosen the distributor and make my tweeks and off to the next race of Van Nuys Blvd.

I get the suspision that those nice simple days are gone. :)
 
elkabong said:
Thanks. I did not know that I needed a Phd in Corvette to work on these things. Ah the good 'ol days. :)

You should check out those Toyota's then! LOL. I swear they must make exclusive Toyota tools that you can't buy in America. I can't believe how much stuff they can cram under that tiny hood.
 
Here's an update. I adjusted the timing with disconnecting the brown wire and set it to 6 BTDC - factory spec. I also drained the tank which I suspected to be the majority of my pining problem - I was planning to do this but did it sooner than anticipated because a new fuel filter plugged in about 50 miles. The fuel removed was yellow (the car sat for 4 years) like urine and had a fine black grit. Apparently it was urine! :) Now the little beasty runs like it should. I took the little beasty out for a lil putt - got the speedo to 125 and decided to slow down. :J Fortunately I live south of Phx and there is a stretch of destert road that goes for about 10 miles - and as luck would have it no one else was on it in both directions but me. (heehee)

I still have a minor issue with a slight hesitation when I take off gently from a stop light. Any suggestions on what to check?
 
I forgot to add this. While I drained the tank I replaced the fuel pump with an AC Delco for a '85. I found it a checkers for $65. Apparently it was changed before me with an 85 but the bonehead that installed it used over sized fuel hose where the pump connects to the metal tube and only clamped metal tube side and not the pump side. So, the fuel would leak back into the tank. But lucky for me the electrical part had already been done so all I needed to do was connect it up the new pump.
 
When the 82 had a slight miss at about 800-900 rpm it turned out to be build up in the EGR. I just cleaned up the port and never had the problem again. Quick and cheap. Worth a look.

Carlo
 

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