Eric's '90 80QT: rustic bits

[DE80q]

Thanks eric, for asking all the questions I was going to here in a few weeks.

[AudiSport4000]

I got some foam from Home Depot. It wasnt the recommended kind another MG'er suggested (couldnt find it) but it worked well. It is a bit thick but we cut it down at the edges. I dont have it near me so I cant say exactly what brand/size it was, but I did put 2 pieces next to eachother and that worked out well. No problems yet!

[my2000apb DrBeastCar]

I put a Thermex in my eS2 a few years ago. No complaints and the new owner hasn't said it's broken yet. Probably only about 4K miles on it though.

And the $44 Meyle on AZ is for the older HVAC box found in the B2 chassis. That's what I got for the URQ.

yup chris is right, it was a 4kq one i jsut ordered,
hows it holding up?

[elaw]

Hey here's a great troubleshooting tip for anyone as stupid as I am... if such a person exists!

If your heated seats aren't working, instead of figuring it's because your car is 22 years old or is an Audi, look under the seat for the connector you disconnected while working on the car last summer and plug it back in. You might be surprised at the results! :tard: :tard: :tard:

[DE80q]

great tip! I just wish thats why mine doesn't work.

[PRA4WX]

Hey here's a great troubleshooting tip for anyone as stupid as I am... if such a person exists!

If your heated seats aren't working, instead of figuring it's because your car is 22 years old or is an Audi, look under the seat for the connector you disconnected while working on the car last summer and plug it back in. You might be surprised at the results! :tard: :tard: :tard:

I have that kind of stuff happen mo frequently than i like to admit....

[elaw]

So today's lesson is "How to make your car go faster with two resistors"

Well maybe it won't *go* faster but it will appear that it can go faster!

What I'm talking about is, for those of us with 20v cars, replacing the gauge face on the speedometer with one that can go up to 160 MPH. Replacing the gauge face itself isn't terribly hard, but if that's all you do your speedometer will be grossly inaccurate. You also need to tweak the electronics so full-scale is 160 instead of 135 MPH.

That's where the resistors come in:

Take a 390K and a 56K 1/8 watt resistor and solder them in series to make a 446K resistor. Then solder the pair across the resistor shown on the speedometer PCB and voila! you now have a correctly-reading 160 MPH speedometer. :-)

[elaw]

So like the title says (depending on when you read this), here's today's "WTF moment"... my leaking heater core:

Does that look like a leaking heater core to you? Nope, it doesn't look like it to me either. AARGH! :frustrated:

I don't think it's a teeny non-visible leak, either. The car's been losing maybe a pint of coolant every couple of weeks, yet the inside of the HVAC box where the core goes is completely dry.

Okay so tearing the entire car interior apart wasn't entirely for naught. The HVAC box flaps desperately need to be re-foamed so I can do that. Since I bought a new heater core I might as well toss it in there... the one in the car looks original (22 years, 224K miles - not bad!).

And it'll facilitate a couple of other projects too. The brake booster is leaking, and this makes access much easier to swap it out. I've got this goofy idea to connect a cruise-control vacuum actuator to the throttle pedal, this will make that easier too. And the Megasquirt folks just implemented "check-engine light" functionality, so I'm gonna see if I can make that work - there are already provisions for it in the cluster.

And one thing that's kind of funny: with the dash pulled apart this much, you can finally see the Megasquirt ECU!

8)

[DE80q]

Interesting, if it wasn't coming from the heater core, where is it coming from?

[elaw]

I wish I knew! :(

I've looked pretty carefully and haven't found any leakage under the hood, and there are no puddles under the car. Initially I thought it was just trapped air getting out of the system but it's been consuming coolant steadily (if slowly) since I've been driving the car which is almost two months now. It seems like the rate of consumption has increased recently although that could be my imagination.

One obvious answer is "head gasket", but there are no related signs of that like poor running or overheating, and this same engine in my other car never consumed a drop of coolant.

I did smell coolant inside the car but only once or twice, and there's an air leak through the firewall so it's possible leakage under the hood would cause a smell in the car.

Oh well, the search continues...

[savagerocco]

My car was eating coolant mostly in the morning when cold. Once car heated up it sealed up. But it missed and blew white smoke for a few minutes. You did see my motor pics though.....
Sent from my SAMSUNG-SGH-I717 using Tapatalk 2

[85oceanic]

Might want to pressurize the coolant system with a pressure tester in order to track down that pesky leak.

[AudiSport4000]

I would get a foggy windshield but there was no coolant in the heater box when we removed it. I knew it was bad so I bypassed it until we replaced it.
Pretty interesting about the speedo. I had cobbled a good one together for my car a few weeks ago and was all set to replace the gauge face in mine when I noticed the one I was going to use was a 160mph one, which obviously would not work. Neat information to make it work, thanks!

[85oceanic]

Another thing that can cause a foggy windshield is a clogged AC drain pipe, but where it's eating coolant it's gotta be going somewhere.

[elaw]

Yeah I think a pressure test is the next step... that is after I get the interior put back together!

[(4x5)v=20v]

Yeah I think a pressure test is the next step... that is after I get the interior put back together!

I would pressure test that heater core. I'm getting ready to drop the dash in my CQ for a heater core job and there's no way I'd go withouth replacing a $50 part after all that labor.

[elaw]

Oh yeah, the only place that core's going is in the trash. I ordered a new one before I started and no way I'm gonna toss a 22-year-old one back in there!

The job's not a total loss anyway - the flaps in the heater box desperately need re-foaming. So that'll get done now which is good. A PITA but good!

[elaw]

So continuing our "WTF-themed" discussion...

Take a look at the relays in the car:

Note the one on the left marked "76". From what I read, that's an ABS relay. Which is fine, except this car doesn't have ABS!

Does that relay have some other function?

[AudiSport4000]

Wut? I thought all B3's had ABS. Could be poorly mistaken, though

[savagerocco]

That is indeed an ABS realy. Had one on a coupe that had a blown fuse, so I remember changing the fuse. Might just be that they installed it with the option of abs or not.

[elaw]

Wut? I thought all B3's had ABS. Could be poorly mistaken, though

I don't really have anything solid to base this on, but I would have figured in general the low-line 80 model would not come with ABS and the higher-end 90 model would?

In any event, although it might at some point in the future, this car definitely did not have ABS when it was built.

I did think of an alternative interpretation: maybe "ABS" stands for "awaiting boost someday"? In that case, since I have installed a turbocharged engine, that relay should be removed.

[AudiSport4000]

I didnt think about the 80/90 difference with ABS, so that may be. Dont see too many 80q's around, unforunately :(

[elaw]

I'm guessing a few around here are familiar with the concept of "scope creep"?

Along with the heater core, there are a multitude of other things I'm doing while the dash is out. The HVAC box got new foam on all the flaps (I'm now qualified to teach at "re-foam school"... ba dum dum) and I took apart and lubed the blower motor to hopefully extend its life a bit.

The brake booster was leaking, so I took advantage of easier access with the dash out and replaced that. And a few weeks ago, I had bought a larger brake master cylinder from Austin (Yodasfro) that I wasn't 100% sure would fit but decided to give it a try. The result: success! No mods or drama needed - it just bolted in. This is a 25.4mm (aka 1") master from a 20v 200q so if anyone else out there is upgrading to larger brakes and wants to know what larger master would fit, the answer is this one!

The next challenge is going to be fun... I'm trying to figure out how to connect a cruise-control actuator to the throttle pedal. There's really no good place on the engine with my relocated throttle body so I'm hoping for an inside-the-car solution. Stay tuned for the results on that one...

[mrmotorhead13]

Wonder if that master cylinder will work with bomb brakes on a 20V... though come to think of it I believe the stock CQ master is 25mm and I know that would fit.

Nice that there's an easy bolt-in for the 20v cars though.

[mr_aj_johnson]

Eesh, there isn't a whole lot of room around the throttle pedal. I'd love to see what you come up with.