83 Distributor drive question

[Classic83owner]

I have a 83 ZX 2+2 NA 5 speed that I put a 79 engine in. Swaped intake and a few other bolt-ons including the distributor mount because the adjusting screw was clocked different. When I dropped in the distributor I noticed that it only has about 1/8" of engagement with the drive gear/shaft, that is, it only drops down 1/8" when it lines up. Does anyone know if the drives are different. It seems to cause a bit too much free play in the distributor. The car runs pretty good but I'm still concerned that it may cause future problems. I bought the car without the engine and a pile of parts in the back. It has power steering but the 79 did not so I had to swap the drive pulley and the timing pointer for the original motor must have been eaten by the gremlins that haunt the car. With that said, I can only time it by ear and I can't put a timing light on it to look for fluctuation. I can't help but wonder if it's a real issue I need to worry about. Like I said, it seems to run good but I know it should have more power. (I'm pretty sure the lack of power is more related to my MAF than timing.) Thanks in advance for your help in answering this.

[sjb15316]

I overhauled my 83 and installed a new distributor, but for the life of me, I can't remember how much "drop" it had. Did you by chance compare the two distributors??? I know it would be a job pulling it, but as you say, you don't want a future problem. I've got the old one in the shop if you want me to give you the dimensions... let me know. BTW, eBay has a "new" pointer on sale... the eBay item number is "230957112146". It and shipping is less than $15. Good luck

[Classic83owner]

I did compare the two and they were the same, but I don't have the distributor mount anymore that was on it and never compared the length of those two. The timing set screw was positioned different and the plate on the bottom of the distributor was different as well so I just swaped the mount with the PO who still has the original block. Pointer wasn't there at all. Thanks for the info on a new pointer.

Also, I've noticed another thing that worries me that may be related. After the car has warmed up I get a weird fluctuation on the tach on decelerarion. I got the digital dash and when I let off the gas and during shifts the tach will flutter upwards maybe 500 RPM, real erratic like and bouncing all around.

Again thank you for the reply and I'll check eBay for the pointer.

[sjb15316]

I have the analog dash in my 83 and I know it fluctuates similar to that - not sure of the exact amt - but, I've got a problem with a "miss" I've been trying to find since I got it back together and cranked it 6 months ago. I've done all the usual stuff, new wires, plugs, cap, button, O2, searched high and low for vac leaks, etc... and still an erratic miss. Exhaust smells rich to me, so today, I'm going to "attack" the fuel side of the car and see if I can find anything. I'll run my car today and pay (closer) attention to the tach and see what mine is doing and let you know. Is yours missing? We may have the same problem. I'll post my findings (if any) late tonight. Good luck

[Classic83owner]

Yea I do got a miss at normal temp that seems related to the other problem. At idle it will sometimes drop RPM and almost stall with an erratic miss. I can give it some gas and it runs fine until I hit about 3200 RPM where it stumbles and falls on it's face. Doesn't matter if it's under load or not. It doesnt do either when it's under about 170 degrees. This saturday I'm installing a new o2 sensor and moving it's location closer to the head. I'm running a 6-2-1 header and I currently have it at the collector. Previous thinking was that I would get better readings using gases mixed from more cylinders. Now I realize that it's not getting hot enough to read right when the other sensors tell the ECU it's running at normal temp. Did you see my o2 sensor testing post that I found on ALLDATA?

This is word for word courtesy of ALLDATA:

1) Disconnect the oxygen sensor pigtail and connect a high-impedance VOM with the positive lead on the pigtail and the negative lead to a good ground.

2) Start the engine and let it warm up, if equipped with an air injection system, disable the system so as not to get false tailpipe readings.

3) Grab the disconnected wire that goes from the oxygen sensor to the ECU with one hand. With the other hand touch the negative battery post or a good ground. The readings should increase on the VOM up to approx. 1 volt and there should be an increase in tailpipe CO.

4) Move your hand from the ground side to the positive post of the battery. Your body will act as a proper resistor and allow a small voltage to the ECU. The VOM reading should fall to almost 0 volts and the CO reading at the tailpipe should go down.

5) If the tailpipe readings acted accordingly but the VOM readings from the oxygen sensor did not go up and down, the sensor is defective.

I didn't have a gas analyzer to use but I could tell by the way it ran during this test that it was running rich and lean when it should... but my voltage readings never went above .675 and the drop was slooooow to about .375 after 90 seconds or so and slowly ticking down. Gotta be it's location. If I move it I might as well use a new one right? I'll check back tonight or early tomorrow for your results. Thanks for your help!!!