legacycentral bbs

Hey Vikash,

I'll give the new version a go once i finish answering your post.

I still have the stock boost control setup, using the controller I bought off you. According to your program, the most I got today in 3rd gear was about 5.5 psi. I don't know why it would be shut off, as the ECU was freshly reset this morning. Maybe its shutoff while its learning my driving habits? I dunno. When it happened with yours, did it come back on by itself?

Oh, and I suspect the A/C stuff isn't working for me because I'm out of refrigerant. Having looked at the wiring diagrams, that's the only reason I can see for the system not coming on. Guess its time for a R134a conversion

Edit: Ah good... I was going to suggest a revision history on the webpage.

It does look like you're actually getting no ECU-controlled boost.

On my car it started happening after I did a lot of messing with the boost control wiring when I was experimenting. It was a weird situation; the ECU stopped driving the solenoid but threw no trouble codes. But, when I put it in test mode, I got fuel cut whenever I tried to go on boost! Resetting the ECU and cleaning the solenoid fixed it.

I already cleaned the solenoid I sold you, but not while it was running. I guess it can't hurt to try cleaning it again.

It may have also happened a long time ago before I understood what was happening. That time it just healed itself after a week or so though.

I'll try cleaning the solenoid. I put the car in Test mode, and the duty cycle read 50%, which sounds right. But when I started the car with it still in test mode, no change from 1.56% when I blipped the throttle. Maybe I need to be actually driving the car? I haven't had it out on the street in test mode. I should try that.

Have you looked at the relay display while the car's in Test mode? I was able to link the relay / solenoid sounds I heard to the actual devices by looking at when the display indicated they changed. My A/C relay is switching ok, but I'm still not getting a value for the A/C switch. :S

Stupid car!

If you're looking at the knock sensor correction it typically is around 0 for my car, and depending on how I drive, I'll see it go to -1 on occasion and back to 0.

for the a/c is the clutch activating? If not....yeah you may not have any refridge so it's keeping the system protected

Legacy777 wrote:If you're looking at the knock sensor correction it typically is around 0 for my car, and depending on how I drive, I'll see it go to -1 on occasion and back to 0.

for the a/c is the clutch activating? If not....yeah you may not have any refridge so it's keeping the system protected

Looks like all the values are within spec then.

Nope, the clutch isn't activating. I checked the connector, and didn't get 12V. I wonder what a retrofit kit costs up here?

Just need to figure out why the ECU isn't controlling boost, and I'll have this car squared away, finally.

for the a/c, you don't need any special kit. I posted something in one of the forums (think misc) about my ac conversion. I would recommend you do something like that. Far cheaper, and much better results.

You'll probably want to replace o-rings and blow some cleaner through the system.

I remember that post. I'll have to go reread it. Thanks Josh.

First I want to figure this ECU stuff out. I'm gonna go reset my ECU again, but leave it unplugged much longer than I have been. I think that may be my problem, I've been trying to rush it.

You're referring to unplugging the negative battery cable, right?

Didja press the brake pedal while the cable was disconnected?

If I remember right, the official retrofit kit just consists of new o-rings, adapters for the fittings, a replacement pressure relief valve, and a new receiver/dryer. All except the relief valve you should be able to get at the auto parts store; I don't know exactly why you should replace the relief valve. I guess it's not critical judging by the fact that Josh didn't have to.

Yup, undid the negative battery terminal, and yup, pressed the brake pedal for a minute or 2. I'm going to try fuse 14 for an hour or so.

As for the A/C stuff, I'll move my questions about it to either a new post or Josh's retrofit post, depending on what its about. I don't want this thread to wander too far away.

That's it... My MBC is going in. Test mode with the car not running - 50% boost control duty cycle. Car running - 1.56%, regardless of what I do with the test mode connectors. No fuel cut when hitting boost.

The solenoid clicks away like crazy in test mode, so I know its working.

So... Anyone have an ECU out of a 92 turbo they want to sell me cheap? Something seems to be broken in mine.

Any year turbo ECU will work, actually. I've run my car with four of the five different turbo ECU part numbers.

Is $100CDN a good price for a 94 Turbo ECU? I wonder if there's anything I can check before I spend the money on a replacement ECU and the gas to get it. It seems to me though that I've run out of options. But I can't see why an ECU on a stock car would suddenly decide it no longer wanted to control boost.

Shoot, got off topic... Sorry everyone.

It's a pretty good price... The 94 ECU will be the same part number as yours: 22611AA694.

If I were you I wouldn't spend the money on it though. Your ECU clearly has the capability to control the solenoid, so it's unlikely that swapping out another ECU with the exact same programming would fix the problem.

Maybe you should just stick with an MBC until we figure out why the ECU actually does this. Several board members (you and I included) have seen this happen. This scan tool will allow us to know for sure whether it's the solenoid failing or the ECU doing it. Maybe we'll be able to connect the dots.

Yeah, I would like to know what's going on. There's gotta be some reason the ECU isn't using that portion of its programming, but figuring out the conditions sound fairly complex. I would offer to help you with the ECU code, but I know I wouldn't be any help. Although I may have a lot of free time coming soon, so maybe I can learn assembly. :S

I'm more confused than anything, as everything I see from the scan tool says the car is running as close to factory spec as can be expected for a 13ish year old car.

Most of my original issues with the solenoid seemed to coincide with high underhood temperatures, however recently i had it fail once when it was about 20 F outside. As soon as i get the scan tool hooked up i will get you guys some information.

wow, I wish I would have read the FIRST page of this post earlier. I have a laptop at work. I'll try and hook up this thing to my ecu this week some time and see what my ecu is reading. Vrg3.....3 words for you...well two words and a slang word:

YOU DA MAN!

it could be really cool to adapt this thing to say a pocket pc.....future release idea.

Thanks.

I have always meant to put this on a microcontroller with a backlit LCD that could be neatly mounted in the dash somewhere. I'd still like to do something like that.

vrg3 wrote:Thanks.

I have always meant to put this on a microcontroller with a backlit LCD that could be neatly mounted in the dash somewhere. I'd still like to do something like that.

That will be the ultimate version of this thing Vikash.

Dang. I had hoped that if I used my MBC to get more than wastegate boost, the ECU might realize something was going on and start using the boost control solenoid. Looks like the computer is still smarter than me. No change in the duty cycle when I blip the throttle sitting in my driveway.

On the upside, now I know what fuel cut feels like.

Does that mean you also experienced the "fuel-cut-on-boost-in-test-mode-without-any-codes-thrown" problem?

No, I tried that the other day. Nothing happened with the test mode connector connected. My boost gauge said 9 in 3rd and 4th, but as soon as I tried for boost in 5th, it cut out. And it kept cutting fuel after that whenever I started to hit boost. The test connector was NOT connected at this point. I didn't have the laptop running, so I don't know what the ECU saw. I may try a run tomorrow, just to see what it thinks the max boost is.

I'm really starting to think my ECU is sufficiently borked that nothing short of swapping it will fix the problem.

Mike,

I have a 1991 ECU you can try

Is there any problem with running this scan tool while I'm driving? Like say my brother is watching the laptop while I drive around?

If you're asking whether it'll hurt the car any, the answer is no. You're meant to be able to use this tool while doing road tests so you can see the ECU's behavior under whatever conditions you want.