The Motronic ECU does store codes. Since the OBD1 spec didn't go into effect until '95, code readers don't work on these cars. Connecting two leads to the proper positions of the connectors under the shifter boot and connecting a momentary switch to the other ends of the two leads, by using the switch to short the leads for a few seconds, the codes are shown by the check engine light flashing in various sequences. The Bentley explains all this and has a chart showing what the various codes indicate. I don't remember exactly where in the Bentley this procedure is, but it's in there somewhere.
~Holland On Mar 24, 2016 1:17 AM, "damac2004" <damac2...@sbcglobal.net> wrote: > sorry just to make sure we are on the same page. you are saying the 02 > sensor black connector is going into the loom to the ecu. and the ground > wire attached to the firewall is loose and surrounding the 02 sensor wire > along the same path? i am paranoid and want to see for myself and am > tempted to cut further upstream to see. > > i thought i read about the codes and bought a cord on ebay to convert from > a little plug underneath the shifter boot i believe that goes to an obd > reader? i will try it if i read right after i get the sucker going, had to > rewire the main power and grounds. many wires have fallen to pieces just > from touching them. scary stuff now that i look closer. > > On Thursday, March 24, 2016 at 12:40:03 AM UTC-7, stevenarguello wrote: >> >> The picture looks just like what I thought it would, the signal wire is >> the one with the connector, the one going to the ground is the shield. I >> think that you're good to go. >> I would have shown you my loom, but it's very different and I thought >> it'd make things more confusing. >> >> Fire it up. >> >> One last thing, I'm pretty sure that your Motronic ecu has codes. I'm not >> sure how easy they are to read or if they help at all. >> >> On Mar 24, 2016, at 1:29 AM, damac2004 <dama...@sbcglobal.net> wrote: >> >> >> >> i forgot to add this picture. maybe i need to look closer but it looked >> like the connector wire is exposed and touching that main ground leg. is >> it possible the connector has its own cover and is running inside inside >> the ground run? i can try and cut some back and look at it. i was >> expecting a special looking wire, my connector wire doesn't look special? >> >> >> i don't really understand how to read the bently. this is the only wire >> i see connected in the 20 pages to the firewall ground on that side. it >> doesn't show a straight run to the control unit but it has a solid line >> crossing into the shielded wire icon on the 02 sensor connected leg. i >> just assumed they were connected or else the ground wire from firewall side >> would go nowhere? >> >> >> is this a pretty common harness on other gas vw's of the same era? i >> wish i could see somebodies stock harness with pictures, maybe i can find >> one at picknpull. >> >> >> >> <https://lh3.googleusercontent.com/-oSf6Tvpz5Xg/VvN7QYR455I/AAAAAAAAAOU/FVftHFgDN0AaCg98N1jFVFSj67xKPaOjw/s1600/IMG_0575.JPG> >> >> >> >> On Wednesday, March 23, 2016 at 5:21:42 PM UTC-7, stevenarguello wrote: >> >> So you bought a new 3wire O2 sensor? If so, the black is the signal not >> the ground. (The sensor is grounded through the exhaust?) >> After the orange connector the signal wire back to the ecu is a little >> thicker because it's a coaxial cable, it has a braided shield around the >> signal wire. This shield has a ground and I believe that's the one going to >> the firewall. That's why they look like 2 wires fused into 1. >> (I think, my loom is different.) If I'm way off, I hope someone will let >> him and me know. >> >> There should be an extra female connector for the 2nd knock sensor, >> unless they cut it off. >> >> >> On Mar 23, 2016, at 6:30 PM, damac2004 <dama...@sbcglobal.net> wrote: >> >> hate to bug people but i'm just tidying things up with a new 02 sensor >> and want to make sure before i start it up and time it. i pulled the whole >> harness that goes to the ecu just to make sure. i do only have the 1 knock >> sensor. don't see any special shielded wiring. >> >> the 02 harness side has a black ground going to firewall that goes to >> the ecu. a small area is cleanly exposing wires and the 02 sensor signal >> wire connector is fused to this ground leg. no sign of solder or cuts, >> looks original to me? >> >> i also tried looking up my car in the bently and it matches a later gti >> 91 chasis according to them. it shows the ground location over there on >> firewall rather than the engine block. >> >> i have the 2 white wires from 02 sensor going to stock connectors and >> their colored wires into the ecu harness. >> >> bently shows the ground leg black wire and the 02 sensor connector black >> wire making a left turn into that black ground wire. >> >> so it seems it is wired correctly? >> >> i just don't understand how 02 sensors work, not sure if that black wire >> is a ground wire on all car applications. >> >> On Saturday, March 19, 2016 at 1:24:08 PM UTC-7, stevenarguello wrote: >> >> The wire you’re touching looks like the O2 signal. In your case it looks >> like the shield might have been pulled off and ran to ground. (That’s a >> guess, could be like that from the factory) The red and yellowish (sorry, >> I’m a little color blind) are the O2 heater. The 2 whites and the lead with >> the electrical tape go to the sensor. >> I think. >> >> There’s only one mounting point for a knock sensor on the 1.8, the 2.0 >> has 2. If you have 2 and they’re both mounted to the block then I’d say >> that the block is 2.0. I know we’ve gone back and forth on this, but I had >> the exact opposite happen to me my ’88 had a 2.0 (the PO didn’t know) I >> found out when I discovered the second KS. >> >> On Mar 19, 2016, at 3:20 PM, Holland Phillips <holland...@gmail.com> >> wrote: >> >> As Steve mentioned, the O2 sensor signal wire is shielded, similar to a >> coaxial cable. It's basically a regular insulated braided copper wire of >> about 20 gauge, with a braided shield covering it. >> >> ~Holland >> On Mar 19, 2016 12:13, "damac2004" <dama...@sbcglobal.net> wrote: >> >> im pretty sure i have 2 knock sensors? im attaching a picture of what i >> uncovered from electrical tape. looks like a brown wire covered with black >> that goes to top connector from drivers side, its duct taped along i guess >> stock loom. i assumed ground at first but wonder if this could be the 02 >> sensor signal wire? >> >> and just what i thought. i have a black ground wire coming from firewall >> gong to the loom. but an area is all cut away with exposed wiring. the >> wire from outside of loom was wrapped into this exposed ground bundle WITH >> the 02 sensor signal wire??? >> >> this is incorrect right? ground wire is no the same as signal wire for >> 02 sensor it should make an isolated run somewhere? >> >> whats wierd is all the wires but the loose one outside of loom seem to be >> fused together. i can't detect solder and the wires seem to be attached >> firmly inside the black cover. i can't even pull them apart, i would have >> to cut which makes me think it was stock because i don't see breaks further >> down the line. >> >> >> <https://lh3.googleusercontent.com/-dxq5cmIRnac/Vu2jZVj8m9I/AAAAAAAAAN0/6KQ2liGE3owz3akNdZZU2l2Z-LO6_usig/s1600/IMG_0571.JPG> >> >> >> On Saturday, March 19, 2016 at 10:29:29 AM UTC-7, stevenarguello wrote: >> >> On a typical 1.8 CIS-E the O2 signal wire is shielded and green to an >> insulated male spade connector and there are 2 white heater wires into a >> duplex VW connector. I’m not sure how big of a deal the knock sensor issue >> that you’re going to have is. Your Motronic ECU is going to want 2 knock >> sensor signals, I think it uses one as a baseline reference and the other >> adjusts the spark timing. The 1.8 block only accepts one knock sensor. >> >> On Mar 19, 2016, at 11:31 AM, 'Matthew Yip' via MK2-16v < >> mk2...@googlegroups.com> wrote: >> >> This reminds me of a friend who adamantly stuck to the theory that VW and >> Audi engines are the same because of the engine code. Instead of moving the >> accessories, he installed the complete 1.8t from a VW into an Audi TT. >> >> At start-up, it fired immediately but idled at 2000 rpms. Why? Because >> VW had a 1" fitting underneath the manifold that Audi doesn't use. The >> moral is to never assume and always check the obvious since the obvious >> isn't always obvious <G> >> >> - Matthew - >> >> On Mar 19, 2016, at 11:03, Holland Phillips <holland...@gmail.com> wrote: >> >> Progress! That's awesome! I don't remember the wire colors anymore, but >> yes, one of the wires to the O2 sensor is the heater wire. Hopefully, once >> you set the timing, it will improve things. However, until you get the O2 >> sensor hooked up correctly, it isn't going to run right. But at least >> you've resolved a lot of your issues. I'm happy for you. >> >> ~Holland >> On Mar 19, 2016 01:38, "damac2004" <dama...@sbcglobal.net> wrote: >> >> well i capped off one hole with a bolt/washer and the other with a thick >> plate and gasket. turned the key once to hear the pump prime and then >> tried to start the car and it started right up and idled a bit less than >> 900 rpm i think. >> >> wow do i feel stupid. >> >> i got various little things to fix after poking around but my next >> problem is the cat/02 sensor. i'm going to start fresh with my new cat and >> 02 sensor at this point. i assumed the wiring was ok but noticed some >> previous owner electrical tape and there are numerous wires tied together >> into a bundle thats hooking up to a ground on the passenger firewall. this >> includes a single wire that is zip tied to the outside of the loom coming >> from the drivers side. halfway it turns from black to brown with vw >> plastic connectors. >> >> seems a little goofy at face value to have a single wire shoot all the >> way over there for ground right where all those wires meet. i have to look >> closer but i think something is screwed up if im reading right the 2nd 02 >> sensor connector is a heater wire NOT ground? the other harness with 2 >> white wires goes into the loom. >> >> i have a feeling car isn't even getting a signal from 02 sensor so i need >> to get that straight before installing new one. >> >> i had the distributor at the old setups marks, i will have to time it >> tomorrow i couldn't actually see the marks well when trying the timing >> light in the dark tonight. car runs and is revving out with the stock >> chip/cams, etc. but i noticed right away when i stab the throttle and it >> comes off the idle switch there was a slight gurgle and then it revs out >> but is reacting to pedal. i'm hoping it needs to be timed and that will >> help. >> >> On Wednesday, March 16, 2016 at 7:56:36 PM UTC-7, damac2004 wrote: >> >> oh boy i am feeling stupid and think i have found the smoking gun here. >> >> is it possible that having 2 open holes on the back of the intake >> manifold made the car act this way? >> >> this is not a california chasis so no egr stuff. when i pulled the euro >> manifold one hole had a bolt stuck through it with rtv and another hole was >> held by bolts and gasket. >> >> when i was transferring everything over to the stock manifold i remember >> poking down the hole with brake cleaner hose and hit what i thought was >> solid wall on each. at the time never seeing egr stuff assumed it maybe >> would be drilled out for a car that needed that hardware. >> >> i had filled the holes up with brake cleaner with that side up and don't >> think i paid close enough attention so this whole time it was installed on >> the car like that. >> >> tonight as i went to transfer the old parts back on as my last hope >> effort i noticed some leakage when spraying brake cleaner and a light bulb >> went off. so with those holes up if i spray one hole it fills the other >> hole up. if you leave the manifold sit the level of fluid just sits there. >> when i went to tilt sideways one way nothing happened but leaking out the >> top. when i tilted the other way 2 of the runners leaked the fluid out. >> >> i don't know these cars at all. since the car wasn't running right i >> never wanted to let it run long since it wasn't acting like a real car. my >> mom was watching and said i see some smoke and it sounds funny but of >> course i told her its just stuff burning off and that it wasn't running >> right. couldn't really take a chance to look or feel closer. >> >> i have seen people mention these cars can run crappy with vac leaks and >> they don't run without the intake tubes attached? i'm hoping this is what >> it was. going to make some block off plates and gasket to seal those 2 >> holes up tight and then install all the old parts on it and hope like magic >> its back to normal and then i can smog it. >> >> On Tuesday, March 1, 2016 at 10:41:38 AM UTC-8, hollandphillips wrote: >> >> I just thought of something. Any chance the fuel in the tank could be >> contaminated? Since I think you said you're in California, the fuel here is >> probably the worst in the U.S.. With the ethanol and other crazy additives >> that's in it, it has an extremely short shelf life. >> An other thing, I wonder how the fuel pumps are? If either the main or >> transfer pump aren't healthy, that can cause weird running problems. The >> easiest way to check the pumps is to disconnect the input line at the fuel >> distributor and have someone turn on the ignition for a second. You should >> get a really healthy stream of fuel. As I recall, the main pump operates at >> around 50psi, give or take. >> We're reaching for straws at this point, so the more you check that looks >> correct, that's fewer possibilities to deal with. >> >> ~Holland >> On Mar 1, 2016 10:15, "Larry Velez" <la...@sinu.com> wrote: >> >> I just checked and Marren is still in business and still rebuilding >> injectors of all ages: >> >> >> >> https://www.injector.com/ >> >> >> >> https://www.facebook.com/MarrenFuelInjection/ >> >> >> >> -Larry >> >> >> >> *From:* mk2...@googlegroups.com [mailto:mk2...@googlegroups.com] *On >> Behalf Of *Holland Phillips >> *Sent:* Tuesday, March 1, 2016 12:56 PM >> *To:* mk2...@googlegroups.com >> *Subject:* Re: [mk2-16v] how do i find out what engine i have? >> >> >> >> I agree with you Chad. At this point, I would perform a compression test. >> If that looks good, then I'm at a loss as to where to go next. Maybe look >> at the injectors. It's probably easier and cheaper to try and find some >> used, hopefully known good injectors, even if it's only one. Then you could >> swap them one at a time and see if you find a bad one. There are a couple >> of companies that do balancing and blueprinting of Motronic injectors. I >> had mine done by Marren Motorsports back in the mid '90's, so I don't know >> if they're still in business. They could perform just testing to check for >> flow and pattern. >> Beyond that, I just don't know. >> >> ~Holland >> >> On Feb 29, 2016 18:21, "Chad Rebuck" <chadr...@gmail.com> wrote: >> >> The key in the cam gear is only there for the alignment until the bolt is >> tightened. It doesn't really hold the cam gear in place once the bolt is >> tightened. Same for the crank pulley too. The key can break if the bolt >> gets loose enough for it to turn. >> >> I'm just curious how the engine sounds as you said it ran smoother for a >> short while when you opened up the throttle. >> >> I'm about out of ideas. If you take it to a shop the first thing they're >> going to do is check the timing again and check the compression I bet. >> >> On Feb 29, 2016 9:05 PM, "damac2004" <dama...@sbcglobal.net> wrote: >> >> im afraid to run this car for long but what would be better, a video from >> the engine bay or t >> >> ... > > -- > You received this message because you are subscribed to the Google Groups > "MK2-16v" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to mk2-16v+unsubscr...@googlegroups.com. > To post to this group, send email to mk2-16v@googlegroups.com. > Visit this group at https://groups.google.com/group/mk2-16v. > To view this discussion on the web visit > https://groups.google.com/d/msgid/mk2-16v/8ce3277a-6f60-4598-8854-cd7899128626%40googlegroups.com > <https://groups.google.com/d/msgid/mk2-16v/8ce3277a-6f60-4598-8854-cd7899128626%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "MK2-16v" group. To unsubscribe from this group and stop receiving emails from it, send an email to mk2-16v+unsubscr...@googlegroups.com. To post to this group, send email to mk2-16v@googlegroups.com. Visit this group at https://groups.google.com/group/mk2-16v. To view this discussion on the web visit https://groups.google.com/d/msgid/mk2-16v/CABrbKB%3DUCHenAvNNLhxhY2gMd97gXKhOUVGj83YZuqQfNZrKOA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
