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1981 Camaro Z28

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  • Quite proper!
    DynoDave
    POCI # 72200



    1988 Pontiac Trans Am WS6

    Comment


    • Looks good.

      I had to custom bend the stick on my Pro 5.0 to make it work with the pistol grip. Out of the box they don't typically land on an angle that is both comfortable and doesnt hit the dash.
      -Joel
      1995 Z28 M6 - AI226/234 - autocross ricer
      1984 Scottsdale K10 - 305/4bbl/4spd


      WTB List:Midwest Chasis DS Loop

      Comment


      • Wow, last update was in April, back when it rained for about four years straight. Looks like we need an update!

        I drove the car down to Woodward at the end of July and noticed the steering was a little more sketchy than it usually is (since it needs an alignment, and the steering box seems to have a bit of a dead zone before the pitman arm moves) driving down there and driving back. There was some kind of weird "pop" that could be felt and heard when you'd change direction of the steering wheel, meaning that any time you had to correct, it would pop and move it further, meaning it would overcorrect, which you'd then have to correct, pop, overcorrect, repeat...not enjoyable in the least.

        Last sunday I started taking the column apart to investigate:

        Removing the lock ring - was a bit of a pain to get the clip off, but eventually it came off after a few choice words...


        Turn signal assembly - everything seems to be in order here, but I do have instances where my turn signals suddenly don't appear to be working. You'll hit the lever, it clicks up and down nicely, but nothing happens. Then just as suddenly, they'll be working again. That was real handy last night, driving home from the Dream Cruise in the pouring rain at night...


        Buzzer switch coming out


        Steering shaft spherical joint for the tilt. If you pushed on it and turned the wheel, the pop became muted, but did not go away. This meant it was coming from elsewhere, and vibrating up top.


        On Monday, I decided to pull out the actual steering shaft to isolate, for sure, whether or not it was in the column, or the steering box. This is when I (believe I) determined it to perhaps be due to the lower bearing that mounts in the firewall. It has a fair amount of end play, which I do not recall when I replaced the steering shaft last year. If it was pulled down (out of the firewall), the steering shaft motion was extremely "lumpy" and actually completely bound a couple times and wouldn't move. Pushing it back up (into the firewall) and turning it from the engine bay side (to make sure it stayed up), the fluid was smooth as glass - no pop, nothing. So, I'm not sure if, over time with vibration and driving, it started pushing itself down, since the shaft is collapsible, and started leading to some less-smooth movement.

        Either way, reinstalling the steering shaft with the column shaft end pushed up all the way seems to have "cured" the "pop", for the time being, at least.

        During all that time, however, the rear upper shaft bearing must've come out of place and ball bearings started dropping out of the column. So that meant more projects...

        Thursday, I got the pivot pins out and the upper bearing housing off. I took the time to check the infamous tilt bolts, even though my column wasn't particularly loose or wobbly. I'm glad I did though, because all four were not entirely tight. I removed them, put some Loctite on, and reinstalled them. Good that I was able to take care of those while I was in there! I repacked the rear bearing, and re-assembled everything.




        Getting back from Woodward on Friday night, I decided to reassemble the remainder of the column since I had time, and I got it all back together:


        Morning of the Dream Cruise, I reconnected the battery back up so I could start the car and spin the steering back and forth to make sure everything felt good, and it did. So I decided I might as well drive it down!




        Next up is to figure out what seems like a fuel issue. The car no longer seems to have the strange idle issue, but when you start it now, it idles pretty low. If you rev it, it sputters a bit. Out on the road, if you really get into it, it kind of sits there and sputters and bogs, then it goes. Might be an accelerator pump, might be a fuel pump...
        Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

        "You shall ride eternal. Shiny and chrome."

        Comment


        • Thanks to bri2203 and the team over at Master Works, the car is all aligned and finally not scary to drive over uneven roads. Just a bit of on-center play in the steering box, but that is something I can have rebuilt in the fall or winter.

          Now to figure out this "sputtering" issue...preferably before dyno day...
          Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

          "You shall ride eternal. Shiny and chrome."

          Comment


          • So, back at the end of August I did some more investigation into the carb:

            First what I did was play with the throttle before even starting the car - last time it was started was a week or so ago, so the main bowl wasn't full. What I noticed were slight "fuel bubbles" coming from this kind of "crevice" here in the corner between the gasket and the raised area around the choke flap. You could hear it and see it "lightly" bubbling there when you'd open the throttle.

            p1130310-jpg.82243.jpg
            p1130313-jpg.82244.jpg

            With the car running and the choke flap fully warmed up, it looked like I was getting a good solid spray in the primaries:

            p1130317-jpg.82245.jpg

            After revving it, the car seemed to only want to idle at like 500-600 rpm, lower than it should be, but it stayed there and didn't stall, but it was a little odd.

            I noticed that this rod was a bit wet where it goes into the carb body:

            p1130322-jpg.82246.jpg
            Last edited by MP81; September 9th, 2019, 08:37 PM.
            Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

            "You shall ride eternal. Shiny and chrome."

            Comment


            • I ended up buying the rebuild kit from Cliff, as various sources of input (Joel, Dave, Cliff, NastyZ28 members, among a few others) have pretty much pinpointed the issues to a carb in need of a rebuild. It's most likely the accelerator pump seal has degraded and is just pouring in fuel when you get on it, making it bog, hard.

              Pulled the carb off tonight to get it ready for the rebuild process this week:

              These first few are more for reference, but I included them in case anyone happens to see something I missed that could have been causing the issue:






              Carb removed - the inside of the intake looks pretty clean



              Carb off the car:





              Fuel filter looks a tad dirty...


              After a quick spray/wipe off with carb and brake cleaner - quite a lot cleaner (especially for doing this outside while being eaten alive by mosquitoes)! Time to let this dry overnight...

              Last edited by MP81; September 9th, 2019, 08:48 PM.
              Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

              "You shall ride eternal. Shiny and chrome."

              Comment


              • The new FI throttle bodies are now getting down in price that competes with a new good carb. I personally would put one on an old musclecar if I bought another one.
                When in doubt, Whip it out !

                Comment


                • It's in the future plans - though if I can get the Qjet working right, then there wouldn't be much of a reason to switch, at least for the time being.
                  Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

                  "You shall ride eternal. Shiny and chrome."

                  Comment


                  • When it?s ?right? a Qjet can be fantastic. It?s when they get old and a little sloppy that people want to toss them in the can.
                    When in doubt, Whip it out !

                    Comment


                    • Yup - when they're not though, it's one hell of a solid carb by design - small primaries and gigantic secondaries - huge WOT flow without having the disaster of light/part throttle response that a big carb can have.

                      Started disassembly:



                      Air horn removed:


                      Main casting with the air horn removed:


                      Gasket removed:


                      Accelerator pump - seal does look mostly okay, I think:


                      Main casting components removed:



                      Well, looks like the plugs were removed down here:


                      Throttle plate removed:


                      Fuel bowl plugs have already been epoxied in the past:


                      Throttle plate gasket removed:


                      So, this thing definitely has been off, and apart, before. I need to do a quick soapy water test and see if the bowl plugs are leaking or not, but the epoxy looks to be pretty solidly on there, so we'll see. Everything is really quite clean inside. Nothing seems gummed up - everything moves quite easily and freely.
                      Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

                      "You shall ride eternal. Shiny and chrome."

                      Comment


                      • Yeah, doesn't look too bad in there. Clean passages, new float set to the proper level, new accel. pump, a few adjustments...than you should be good to go.
                        DynoDave
                        POCI # 72200



                        1988 Pontiac Trans Am WS6

                        Comment


                        • Yup - I'm wondering if it really was necessary, but knowing it's done (and hopefully I don't manage to screw it up too badly - I think I may have mangled the roll pin for the accel pump a bit, as it won't back out far enough to get the arm out of the way - I was able to pivot the linkage out when I removed the air horn, though) will be worthwhile.

                          I forgot to mention something very important I noticed when I removed the carb...the damn bolts were hardly even finger tight. Just moving the socket around to seat it on the bolt head turned them with about no effort...so maybe the issue all along was a vacuum leak (though I can't say I really heard one, but who knows - that engine bay isn't the quietest). We'll find out.
                          Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

                          "You shall ride eternal. Shiny and chrome."

                          Comment


                          • Epoxy came off with a little effort by hand/screwdriver...but I did the soapy water test with my air compressor, and I'm not sure these ever were leaking in the first place. The later ones supposedly aren't as well-known to leak.

                            Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

                            "You shall ride eternal. Shiny and chrome."

                            Comment


                            • I heard in a You Tube video about sealing those plugs that the later cars used a better design not as prone to leaking. All I know is we still got cars with the issue, and used JB Weld as a fix at our Chevy dealer c1986-87-88.

                              I also saw in one of those videos a guy with the same complaint...that JB did not hold up well. Not sure what other product to suggest.
                              DynoDave
                              POCI # 72200



                              1988 Pontiac Trans Am WS6

                              Comment


                              • Cliff Ruggles seems to prefer Marine-Tex, as it is petroleum resistant. JB Weld appears to have come out with a similar product now (JB Weld Marine).

                                This stuff looked like JB Weld - if it was leaking, it'd have peeled off all on its own. It only came off because I picked at a lip it had.

                                I tried two separate times with the soapy water, the second time with a rubber tip on the blow gun and trying to plug where the air would come out and still saw nothing. Even with the air coming out somewhere, I should've seen something.

                                At this point, I really don't have time to wait for epoxy to dry, so I'm hoping my check/results were valid. Whoever rebuilt this thing before may have put it on there as a preventative measure, under the assumption it would eventually leak like the older-style plugs.

                                The plug above the lean mixture solenoid adjustment is removed, so that can be accessed from the outside of the carb - I'm thinking that's how the bowl empties itself - it is essentially an always-open vent from the fuel bowl to the atmosphere.
                                Gone but not forgotten: 1986 Chevrolet Camaro IROC-Z

                                "You shall ride eternal. Shiny and chrome."

                                Comment

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