chaseincats

I'm pretty sure it's working - the vacuum bladder holds air and the plate is movable but I've never tested it with a vacuum pump. That shouldn't affect idle richness though I'd think.

WOT gets to low 13s Timing is at factory which if I remember is 10 degrees btdc Premium 93 octane Off cruise that lean felt pretty anemic There are absolutely no vacuum leaks in that engine at all - I've smoke tested it a few times and found a big one originally but it is perfect now The engine runs well enough at idle that you can put a glass of water on the valve cover and you won't get ripples so it isn't anything internal that's the issue

So I just spent a lot of time playing with the AFM to get it to cruise at 14.6 but I cannot get the idle to sit at less than 16.5 which is way too high with that setting on the black gear (brought the idle screw all the way in). Should I re-richen the black gear a bit and call it a day or leave it like that? I hear tiny little pops in the exhaust when holding it at 3k in my driveway (I did the testing under load though, that was just an observation as I didn't hear pops while driving). I have tested my coolant temp sensor and it is within spec of the FSM and set my TPS before installing the gauge by following the atlanticZ page so my system is setup correctly.

@jonbill Freeway speed sits between 12.3 and as low as 11.9 - I think it's safe to say I need to play with that gear a bit. Am I going to me really turning this wheel or will just a couple of teeth do it?

Stock L28 with original bosch injection. I was reading that with today's ethanol fuel levels, running that lean isn't good for our engines. Or is that a wives tale?

Good to know. I'll take it on the highway tonight and let you know what it says. I just changed the idle to 14.7 now, thx.

What rpm would you say is 'cruise' so I can have the pedal held when tuning it?

So you're thinking I should lean out the drive gear and re-richen the idle a bit? I thought the idle was supposed to be leaner than cruise, no? I did notice after leaning the idle out that the car off the line is a lot zippier. I almost smacked my garage door when turning away from my house the first time I drove it post-tune lol.

Ok gang, here come the numbers on my stock EFI system as-is: Idle: 13.4 2500 rpm shift points: ~13.2 WOT: 12.4 Highway cruise: TBD (will update tonight) NOTE: This is without the high altitude switch on (when enabled it seems to lean the mixture out 1 full point) Changes made: leaned idle to low 15s, will adjust big drive mix gear at a later time. @AK260 Is that chart (except for the ones labeled WOT) for idle, or highway cruise (4k-4500rpm)?

So I just finished wiring the gauge and will be taking it in tomorrow morning to have the o2 sensor bung welded in then I'll drive back and give you guys some numbers. Stock l28 with EFI. I pretty much followed this guys video (even got the same gauge): https://www.youtube.com/watch?v=XS_f2ciKVqo&t=9s

https://en.wikipedia.org/wiki/Air–fuel_ratio_meter#Wide-band_sensors

Again, this is not measured in the intake manifold, there is an o2 sensor welded into the exhaust headers.

It measures oxygen in your headers/exhaust manifold's back piping (not your intake manifold as that's just air not air/fuel). Jonbill also made some good points.

It has an oxygen sensor ("o2 sensor") that is welded into your exhaust. All modern cars have this.

Hi guys, I just purchased an air/fuel mixture gauge (https://www.amazon.com/gp/product/B00N3VGPYS/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) and was wondering where to find the number the car should read when driving/idle. Has anyone done this before? The FSM shows fuel percentages but that isn't readable on these gauges it seems. -chase

If you're talking about finding a replacement for the accordion-style spare that came with the '77/78 (and maybe ZX?) then I don't believe you can get those anywhere. Tires for the standard wheels can be bought off amazon for like $60 each so I'm not sure what he's talking about...

I actually was thinking about that, because that happened a year and a half ago and I ended up changing the alternator which solved it. The difference is this time my volt meter is reading a normal charge rate compared to before which I think was around 15v. I'll keep that in mind though next time it happens.

Well this is a new one... I was driving this evening (about 40 degrees out) and my temp gauge passed the half mark which I have never seen it do outside of 100+ degree heat with the AC on. I noticed that when I turned off my cabin heater fan, the temp gauge would drop down to where it normally sits almost immediately (a little below the half-way mark) but rose back up past the half mark when I turned the heater on again. I had a long drive so I had a chance to try this over and over again and that is oddly exactly what's going on here. I played with the temperature slider to see if max hot would change the degree of movement on the coolant temp gauge but it literally is an on/off issue. How is that possible?

It might have not been in all the way - who knows. Not sure if the dist caps were the same brand as the first one came on the car when I got it years ago.

Ya the car runs great. I put a glass of water on the valve cover the other day and got no ripples with it sitting at idle haha. So you're thinking just shut the hood and move on?

The ignition box says "jacobs electric." I took a look under the cap and it looked fine...

I have a non-stock coil/ignition box - could that be the issue? Basically could the plastic used for these caps be rated for stock coil voltage/frequency?

Thoughts on putting some ox-gard in the terminal to draw current away from the plastic?

Would wrapping electrical tape around the top of the cable's contact help?

Let me try and bulk answer the questions here haha: - I'm assuming the cap is made in china as it's from my local parts store but the wires are NGK - The cap and wires are all about a year old and not corroded at all which is the strange part. This was the case with my old cap and wires and I got the same result. - The odd thing is the car runs great with the cap/wires as-is - The boot for the center wire is pulled up for the same of the picture