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Discussion Starter · #421 ·
I found a rather informative website tonight. It goes into detail on the sensors, the computer, and the output devices of a TBI system. I think it was written more as a guide to install TBI on a carbureted engine, but the info would still be the same. The link:

http://www.gmceast.com/technical/Swartz ... sNotes.pdf
 

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Discussion Starter · #422 ·
I had been fighting with the 35 since the swap, amongst many other codes as well. I haven't checked for the 83 with the jumper wire lately, but the ALDLdroid app shows all clear. Browsing through that, I didn't notice anything geared toward the TCC circuit open code. I don't even know if that code was there before the swap. It's my understanding that an 83 alone won't illuminate the SES light. I never paid enough attention to notice whether it was locking up previously or not. That could have been there all along, I bought that transmission used through a buddy who vouched for it. It works, it's solid, no regrets with it.

I've tried to avoid throwing money and parts at this swap, believe it or not. I DID replace a lot of things while it was apart so I could start with a clean slate, and while the access was easier. Some things I didn't replace due to time constraints, but they're not impossible to get to with the engine installed either.

The old VW EFI really is obsolete, but there's only 2 trains of thought on them that I'm aware of. One camp says go to dual carbs, and the other camp says the factory EFI is a simple system if you understand it and to definitely keep it. Thankfully my VW has a 34PICT3, so I don't need to understand another EFI system. Not to say that this carb is easy by any means though. It's even tougher to work on when you can't even see it because of the body hanging over it. That helped hide the fact my air filter fell off somewhere and I never even noticed it until I went to clean it. I digress...
 

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I've been bookmarking all your little links for the OBD stuff, as I really want to get a ALDL cable for mine. My van has never ran right, and I want to find out what is really wrong with it.

Hope your 35 stays gone...

-Andrew
 

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Discussion Starter · #424 ·
Apologies to 90Safari (and MultiMoto), as I just realized where I found the above link. I'm usually tired/frazzled/done by the time I get on the PC in the evening. I'm glad you're finding the links etc helpful, Andrew. I post them in case they'll help someone else, and so I can find them again later if need be.

Get ALDL cable and the app if you can. John at 1320electronics.com sent me the switch settings and the ADX file I needed VERY quickly, and seemed eager to help if needed. I've never had much luck with Bluetooth devices, but this just worked. Within an hour of walking outside to play with it I'd found my idle speed discrepancy and taut cruise cable. I was able to find it just by browsing the readouts. I stumbled upon it quite by accident by just looking at the data it was showing.

Next up for me: learn more about open/closed loop operation, and look into possibly moving the O2 sensor into a manifold. The sensor is now in the exhaust pipe behind the crossmember. I tried to put it where it originally went, but then the converter was on top of the crossmember and sat at a weird angle. My converter also doesn't get as hot as it once did, I think this is contributing to the difficulty my van seems to have getting into closed loop operation (based on one test drive with the app running to monitor it). Details as they happen...
 

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Big_kid said:
look into possibly moving the O2 sensor into a manifold. The sensor is now in the exhaust pipe behind the crossmember. I tried to put it where it originally went, but then the converter was on top of the crossmember and sat at a weird angle. My converter also doesn't get as hot as it once did, I think this is contributing to the difficulty my van seems to have getting into closed loop operation (based on one test drive with the app running to monitor it). Details as they happen...
Have you thought about moving to a heated sensor?
 

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1989 Astro RS on a 1998 AWD frame with a 1994 350 TBI
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thats what I did I installed a 3 wire heated 02 sensor. 1 wire is ground , one is hot with ignition and the other is to the ECM. I can check the colors of each wire on mine if you need the info. Just PM me and I will get the info, markmitch
 

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Discussion Starter · #427 ·
I've thought about it. I hate the thought of replacing this sensor, it was new in the swap. I guess I'm that cheap in some ways, lol. I wonder if I still have the 3 wire I took out. I also wonder if it would get hot enough. The converter is 18" or 24" further downstream than it was, It's also still hollow. No catalyst means no final combustion.

If I do go back to a 3 wire sensor I'll have to run a switched power wire. The 4.3 had a 3 wire, the 5.7 calls for a 1 wire sensor. With the 5.7 chip I don't think the wires will be powered if they run to the computer. If they run to a switched power source I'll be good. I'll have to check.
 

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Big_kid said:
I've thought about it. I hate the thought of replacing this sensor, it was new in the swap. I guess I'm that cheap in some ways, lol. I wonder if I still have the 3 wire I took out. I also wonder if it would get hot enough. The converter is 18" or 24" further downstream than it was, It's also still hollow. No catalyst means no final combustion.

If I do go back to a 3 wire sensor I'll have to run a switched power wire. The 4.3 had a 3 wire, the 5.7 calls for a 1 wire sensor. With the 5.7 chip I don't think the wires will be powered if they run to the computer. If they run to a switched power source I'll be good. I'll have to check.
What Mark was saying, is that you power up the heated O2 sensor with the key on, using the ignition as your "switched power". This might help get your engine to run a little leaner. I don't know if your cat will get much hotter since it's hollow though. It couldn't hurt to try it though. You just have to find something that has 12 volts when the key is on, and nothing when the key is off.

I'm wondering if you need to access the trans side of your ECU to get to the 83 code. I don't know if GM had them separate in 95 yet or not. Or if it's just in another part of the ECU.

Big_kid said:
The old VW EFI really is obsolete, but there's only 2 trains of thought on them that I'm aware of. One camp says go to dual carbs, and the other camp says the factory EFI is a simple system if you understand it and to definitely keep it. Thankfully my VW has a 34PICT3, so I don't need to understand another EFI system. Not to say that this carb is easy by any means though. It's even tougher to work on when you can't even see it because of the body hanging over it. That helped hide the fact my air filter fell off somewhere and I never even noticed it until I went to clean it. I digress.
There is a third thought, and that's to run the Weber 2 barrel on it, which forces you to cut a hole in the load floor and put a box above it, but that's a very bad idea, and an even worse set up (runs like crap, looks like crap). The VW EFI has 22 wires, and a simple VOM continuity test and 15 minutes you can test them all. The sensors are for the most part out in the open, and a simple ohm test to read ohms tells you if they are go/no go. The main things you have to watch for are having 28-32 psi fuel pressure, 13.5 to 14.4 volts of power (anything less than 13.1 volts causes it to run rich), that the trigger points (for the injectors) are clean and lubed. If a head temp sensor suddenly comes unplugged it'll stop running. That's the main ones as far as the FI is concerned. Everything else is the same issues as a regular air cooled VW. My 65 Notch does run dual carbs (32 Solex PDIST's). The biggest issue I used to have with them was the electro-idle jet unscrewing from the carb body. Loctite on the threads helps, but going to a mechanical jets is the cure. To fine tune them, you remove the air cleaner, and the right operating rod, and dial them in using a uni-syn, starting with the left carb (master), and adjusting the right carb to it. Then reinstall the right pull rod without changing the idle speed. If it changes, then adjust the rod length until it doesn't. Put the air cleaner back on and you're done.
I've found over the years that it's pretty much a set it and forget it set up once dialed in.
 

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Discussion Starter · #432 ·
Well, my bummer butt drove the van a bit today. I took it to a buddy's house this morning, to the rec center, then home. It stalled while backing out of parking spaces on two occasions, but otherwise ran well enough. No lights, no hiccups, no catastrophic failures. No news is good news, I hope. Next up: Air only comes from the defroster syndrome has finally caught up with me. I think I saw a thread here somewhere... (/off sarcasm)
 

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Discussion Starter · #433 ·
I'd post a followup, but if I do- sure as hell the light will come on. That being said, it's up to 184,XXX miles now. My daughter used it as her daily driver for 2-3 months, even taking an ill advised road trip with it, and I never got any phone calls. When I got it back there may have been cocopuffs all over the place (kids) but... I won't say it (or type it). I still have a punch list, but the things listed are getting smaller. I dare not say it, but if I did dare to, I would. You know what I mean?
 

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Big_kid said:
... When I got it back there may have been cocopuffs all over the place (kids) but...?
OK, so ... we bought a box.
Delicious.

And, as I thought... Cocoa Puffs.
Couldn't believe it. And I thought all the previous spellings were good - I smiled at the spousal unit.
She gave me that look...

FYI

Mike
 

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Discussion Starter · #440 ·
I'm glad you're benefiting from it, that's part of why I wrote it. I'm glad to help other swaps if I can.
 
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