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bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Well, my spark plug tester thing showed a spark, and I did briefly get it to run a bit the other day, but something is definitely off. It previously started quite easily, even if the ignition timing was a bit off. I got new plugs, that's the only part of the spark side of things that wasn't tested with the spark tester. Haven't had a chance to try them yet....

924RACR · Posted: Wed Jan 12, 2022 9:59 pm Post subject:

For the longest time I had issues on my S2 with inconsistent spark. Countless no-starts etc.

This was a primary motivation in switching over to Microsquirt.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Mike9311 · Joined: 14 Dec 2004 Posts: 1678 Location: Chicago-ish

I second the starter fluid comments

Had a situation years back headed into night one of a 92Forty weekend. had just reassembled a bunch of stuff. S2 would not start no matter what. In the end I swapped a coil in from my original S1. It fired up like nothing was ever wrong. Of course night one celebrations were off the table that night but at least problem got solved

If memory serves at one point I did have a spark but with a plug pulled and up laying on the engine which is totally different than a spark generated in the cylinder. You may see something outside but it still isn't what you need
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

I suspect you guys are right. I know fuel is getting in there. The spark tester result made me think it had to be timing, but I've verified both ignition and cam timing multiple times. It's certainly close enough to fire.
_________________
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1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

peterld · Posted: Thu Jan 13, 2022 6:47 pm Post subject:

Does this not all keep pointing back to the 123 Ignition interface?
_________________
80/81 932/8 ROW

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

That thought has crossed my mind. I guess the thing is it started up and ran perfectly before. So the thing that changed was me removing and replacing the head (and the head itself of course) so that seems the most likely thing. And of course, getting spark in the tester also made me think that device is working as designed. But, I was about ready to yank it and put the old Ford Ranger dizzy that it came with back in.

Anyway, I replaced the plugs, cranked it, nada, then started fiddling a bit with the dizzy, got some coughs, and just kept twisting it...it's frankly way past where I thought it needed to be...and this happened:

https://drive.google.com/file/d/1h2x3Ryox_B0L39pfzwkYI_a8hOrMM_7k/view?usp=sharing

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

So, it starts pretty consistently now. It idles OK, not super smooth, but I haven't timed it with a timing light or anything yet. The smoke is a concern. I see it, looking from the top, coming up from beneath the headers. Not sure exactly where it's coming from yet, or if it's burn-off of something dripping or something else. It doesn't really smell like exhaust or fuel to me. Tomorrow's project is to find that and hopefully fix whatever it is, and then put the rest of the car back together (air box, accessory belts) and actually drive it. Might be a little ambitious lol...
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

924RACR · Posted: Sat Jan 15, 2022 9:47 pm Post subject:

Glad to hear the progress.

Some smoking after major engine work like that is normal, as typically some oily fingerprints etc will end up on the exhaust and such. As long as it goes away once up to temp, in the first warm-up cycle. Otherwise yeah look for leaks.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Good call, I'm not seeing anymore smoke.

A couple things:

Fans are not coming on, so the car will overheat if I let it run. If I turn the AC on, both fans turn on, so that's working. Time to go re-familiarize myself with the fan circuit. This all worked before so I suspect I must have failed to connect something. The temp gauge is working fine, for what it's worth.

If I turn the key to on but don't turn the car on, the oil light lights up solid. The only reason I bring this up is that I was messing with it in the dark tonight, and while running, I very faintly see the oil light. VERY faintly...but when it's on solid (not running) it's plenty bright. I was thinking this is correct operation and nothing to worry about, but now I'm paranoid. Also, my oil pressure gauge is pegged, so I'll bet I screwed something up back there, ugh...
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

924RACR · Posted: Sun Jan 16, 2022 10:24 pm Post subject:

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Apparently that radiator temp switch is bad. When I short the two wires together, ignition off, the driver's side fan comes on low speed. With ignition on, it switches to high speed (I think the other fan comes on too, I didn't verify I just noticed it got louder). I ordered another one, although I'm a little surprised, since I replaced that thing 2-3 years ago. I wouldn't have expected it to go bad.

I also noticed that my oil smells pretty "gassy," presumably from all the attempts to start it, so I did an oil change and bled the clutch while I was at it since it was acting like it needed it.

I think I'll jumper that temp switch tomorrow and let it run for a bit, just to make sure it still doesn't overheat, and then I may take it for an actual drive. I'm nervous lol...
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Latest update. I drove to the store. And back!

One thing I noticed was that the coil has two connections on 1 terminal and 3 on the (35? Can't recall). In other words, backwards from what I need. They're just screwed on, so I swapped them. I have no idea if this REALLY affected anything, but while I still have a bit of a dead spot at 2K (and I can see my AFM jump lean at that point, which is weird...this is at light throttle) If I give it more gas it is fine and when I get into boost it richens up like it should.

The thing I'm worried about is that this may be another manifestation of what I was chasing before I broke everything. If it is, it will get worse over time, so I'm just going to continue driving it around nearby, and see how it goes.

Idle is also quite rough, it sounds like it's missing, but when I give it throttle that goes away.

All in all, huge progress!
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

Cedric · Joined: 27 Aug 2004 Posts: 2608 Location: Sweden

Bump of lean could be a misfire aswell, weird if it only happens at part load. Do you have the standard igntion amplifier?
_________________
1980 924 Turbo
www.instagram.com/garagecedric/

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

Had a coolant leak while test driving because of course I did. The problem is a tear in 93110615900 (elbow from the thermostat to the hard pipe). Oh great, nobody seems to have this, no longer available.

I see the radiator-to-hard pipe elbow (93110615700) looks like it would work if it were cut down a bit, and it's still available. Curious what you guys are doing for this part. Just a generic elbow maybe?
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)

bureau13 · Joined: 07 Sep 2017 Posts: 480 Location: South Florida

I do not, the Mittelmotor/123Ignition distributor replaces the functions of the DITC, stock distributor and ignition amplifier.