lennyK

I've got an 82 RX7 with 44k miles that was running fine. One day it starting stumbling - it sounded like a rotor wasn't firing. The timing lite indicated the leading mark about where the pulley and the alternator belt intersect! (Vac line was disconnected & plugged). I lined up the pulley indicator pin with the 1st timing mark removed the dizzy cap and saw that the dizzy signal rotor was not at all near the pick-up coil. I pulled the dizzy and it was 2 teeth off from where it should be. There was no wear on the gear and the pin was not broken. I installed the dizzy the proper way (aligned the tally marks on the drive gear and housing) and reinstalled. The timing was right on when cranking but the engine did not start at all. I deflooded just in case (plugs out, MMO down the carb, cranked for a few seconds, a few times, reinstalled dry cleaned plugs) - no start. I used a visual inspection scope to try to see the distributor drive gear but I couldn't get a good look at it. The dizzy was not loose. I checked end to end adjustment of the dizzy and that would only account for about half of the error I saw. Timing lite shows spark on all leads, and compression is fine. When I returned the dizzy to it's position where I found it when the problem first occurred (2 teeth off) the engine started but has the same issue as before - sounds like a rotor is not firing and leading mark about where the pulley and alt belt intersect. I hope I am missing something but so far I'm stumped. Help?

Kentetsu

When you checked the timing, were you connected to a spark plug on top of the motor, or one of the lower ones?

Where in Michigan are you?


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lennyK

Bottom - the leading plug. Hooking up the timing light to the trailing plug would only account for 20 deg. The timing light shows the leading mark about 90 deg from the indicator pin.

I'm in Ann Arbor.

Rotospeed

iTrader: (8)

The pully with the timing marks can be on wrong, check that the engine is on tdc then check that timing marks line up. I think the prosess is in the faq

lennyK

Thanks, Rotospeed - the pulley was on wrong. I searched the forum on how to find TDC and got all sorts of results. I used 2 methods. 1- mark the pulley in the 2 spots where the apex seal appears centered in T2 & L2, then split the difference. 2- remove inspection shield and align the flat of the flywheel vertically with flat side of engine. Both indicated TDC at the same place. The question remains as to how the pulley got mounted wrong. My mechanic did change the water pump a while back. Does the timing mark pulley get removed to replace the water pump?
As to my original problem of the engine sounding like a rotor wasn't firing, it wasn't. Though I checked for spark with the timing light I did not check the spark plugs. One was bad. The pulley was on wrong but the timing was right on so it was a red herring to the 9th degree.
Thanks again for your suggestion.

Alex84GSL

This should be archived as "How to do all your homework, searching and THEN post a well-explained question." Hell I learned a lot just reading your first question!

lennyK

Actually, the problem came back but I'll repost since the dizzy and timing is OK.
My last question remains, however. Is the timing mark pulley removed when replacing the water pump?

roondawg

iTrader: (1)

nope

notveryhappyjack

iTrader: (4)

that main pulley should only be removed during assembly/re-assembly of the entire motor, the water pump should be 100% accessible with the pulley installed. I think removing main pulley while the engine is fully assembled in the car would not be wise. Please check into that before you just unbolt it

lennyK

Sorry, my question wasn't clear. The timing mark pulley was at some point put on incorrectly and I'm trying to figure out how. I was wondering if my mechanic might have thought it necessary when he replaced the water pump. There was no other major engine work done. Any thoughts?

Rotospeed

iTrader: (8)

I don't remember if the pully needs to come off but I think I took mine off when I changed my waterpump.

ArmyOfOne

iTrader: (12)

I know I have removed the pulley when replacing the water pump. On earlier engines it is possible to mount it any of 4 different ways. But if it was running fine and just started crapping out then the problem lies elsewhere. I had one give me headaches because it actually ran 90' out but had no power. Almost ended up pulling the motor because of it and found the mistake on the day I was going to pull it. Lol.

Siraniko

iTrader: (13)

During W/P change out, the main pulley doesnt need to come off. But if the hub/pulley for P/S and A/C belts are in still in tact to the main pulley, there is a chance that someone have unbolted the 4 10mm bolts, removed the entire assembly and reinstalled it incorrectly. So since you're somewhat lagging on the details, I would the following:

1. Locate TDC using the flywheel trick.
2. If 0 timing mark on the pulley doesnt line up with the pointer on the front cover, reinstall the main pulley.

lennyK

The mechanic that worked on my car left the garage where I take my RX so I'll never know if he installed the pulley incorrectly. For now rather than reinstal the pulley I made a new mark for TDC. I reposted my original problem since it is not a dizzy/timing issue. Thanks to the forum for helping me resolve that.