dkbrucedvm

I would appreciate any ideas that might help here. The patient is an 84 GSL with about 20K miles on a factory rebuilt engine. This winter, I lost the rear ignitor, so I had to pull the distributor. To make a long story short, $300 worth of parts later I reassembled, set static timing, and cranked, but the engine idle roughly but not run. Good spark, everything looked good. Tried to set timing at idle, but did not have enough adjustment on the clamp bolt to the the timing marks to align. Out of desperation, I switched the 1 and 2 rotor wires (now the rotor in front is firing on 2, one in the rear is firing on 1), and poof! it runs! Of course, now the timing marks do not align in any way, shape or form. But, by bumping the distributor over one tooth (can't remember which way), the engine now runs great, though it still has an occasional backfire in deceleration.

Now, the person I had put the engine in does good work, but I'm not so sure about everyone he has working for him, so anything's possible. I re-hooked-up the rats nest myself, it seems to be plumbed in right. I read the thread on setting timing by idle, and I'd follow their instructions, but I don't know how to find top dead center on the engine without disassembly. Is there an easy way, since I don't trust the timing marks any more? Should I just leave well enough alone, since the doggone thing runs (and runs well), despite the fact that the ignition is in backwards (or upside-down, or something)?

Any ideas would be greatly appreciated!

Siraniko

iTrader: (13)

https://www.rx7club.com/1st-gen-archive-71/ignition-main-pully-timing-525909/

dkbrucedvm

Thanks for the quick reply. I think I found the inspection port, but it'll be about a week before I can verify the timing. I'll let you know what it shows.

dkbrucedvm

Had a minute to find the plate - it's on top, between the rats nest and the oil cooler I think. No time to pull it yet - hoping to get it done over the Memorial Day weekend.

dkbrucedvm

Sorry about the delay. Life seldom goes as planned, but here lately it's been even less so. But at least not boring.

I pulled the inspection plate, and the gap in the flywheel appears in the inspection port when the yellow timing mark lines up with the timing pin and continues roughly until the red mark lines up with the timing pin. So it appears the pulley is on the shaft OK.

The trailing ignition circuit is hooked up to the coil toward the front of the car. T2 and L2 are hooked to the rotor toward the front of the car, T1 and L1 are hooked to the rear rotor. Isn't this backwards? Timing light does not show L1 firing anywhere near the right time.

Yet the engine runs great under load and gets ~20 MPG around town. Idle is rough and tends to stay at 1100 rpm rather than dropping to 750, but I think that's due to a vacuum leak somewhere. There is a minor backfire during deceleration, but that seems to be highly dependent on the timing. Anything else I can check? It seems something wasn't assembled right, but I don't know where to look.

Thanks in advance. I'm stumped.

dkbrucedvm

AHA! I saw the pictures in Brandon Davis' thread on this subject - I had the wrong inspection plate! So the engine is certainly NOT aligned with the timing marks!

OK, I'll try to get that straight...

(See, I do use the search function. Sometimes!)

MosesX605

I thought that the leading coil was at the front...

Of course, it's been years since I had my coils in the stock location, so I could be wrong.

In any case, yeah, you're out of phase, timings off by a rotor face, which is why it runs well when you swap the firing order front to back.

RotorMotorDriver

iTrader: (1)

No, trailing coil is in front if I remember correctly.

Instead of swapping ignition and all that crap, what was wrong with just pulling the distributor back out, setting static timing, then putting it back in? Sounds to me like thats what you need to do anyway...

~T.J.

trochoid

iTrader: (6)

Agreed. Since you've run out of slot on the dizzy to change the timing, the dizzy was off a tooth or two when it was installed. Set the engine to TDC, then make sure the timing pulley is in the correct 1 of 4 possible positions. Once tha's done, pull the dizzy and reset it.

dkbrucedvm

Tuesday I think I'll have time to reset the pulley to proper TDC. Then I'll pull the distributor and reset everything the way it should be.

I had deliberately set the distributor off one tooth, as that was the only way I could get the timing adjusted to where the motor ran well. Hopefully that will be no longer necessary, but I remember reading that if the distributor drive gear is in backwards you have to do that. Then if I get REALLY ambitious, I'll track down that vacuum leak!

Thanks for the help.

trochoid

iTrader: (6)

You read wrong, Install the dizzy per the FSM.