yourmom

Hmm, thanks cougar - that's one I didn't check on. I'll take a look and clean up that ground point...

Yeah, I swapped out the ECU with a similar model from a local junkyard (CA Auto Turbo AA480 vs 49-State Manual Turbo AA410) and so far so good. Resistance appeared lower although still over 10ohm (I think it was reading 18ohm). I drove around the neighborhood for about 30 mins and all was good but the true test is tomorrow when I drive ~100 miles with it - hopefully don't end up stranded somewhere ridiculous... I still haven't figured out where in particular the ECU grounds itself, although suppose it could be through the casing itself.

I picked up an AA480 and so far so good. The car seems to run although it would work fine before and then suddenly quit, so I need to get some miles under it to be sure. Now I'm getting codes 34 and 51 which are manageable and non-critical. We'll see how things progress. Thanks for the replies, folks. -Hamish

I'm going to head to the junkyard and look for one to pull. I'm driving a 88GL MPFI Turbo. Can I take one off of any MPFI car? My ECU has a bunch of numbers on it: Big font: 20 First top box: 22611 AA410 Bottom left box: A11-000 R15 Bottom right box (stamped): 8118 Help much appreciated! -Hamish

Hey y'all - I'm trying to get my new EA82T 88GL Turbo back on the road but some electrical issues are preventing that. It was showing a lot of historical codes but the one that seems to be the big one is the airflow sensor / Hotwire MAF. The reason I say that is that the car starts and idles fine with it disconnected, but dies when it is connected. Using the factory manual I think I have traced this to unusually high resistance on the B terminal, which is the connection between the MAF and the ECU. According to the factory manual, resistance between here and ground here should be less than 10 ohm but has ranged between 51-90 ohm. Resistance along the line itself to the ECU is less than 1 ohm, so the issue appears to be internal to the ECU, between that pin (#5) and ground. Although the factory manual says replace ECU, I wonder if someone knows where I can find the actual grounding point for the ECU wires? I'd like to clean that up before I'm sure the ECU itself is hosed - after all, the thing seems to work for the most part, whereas I expected more of a total failure mode... Other ideas are welcome - I have already cleaned up the grounds that I know, including - battery to transmission (2 gauge) - transmission to body (new 2 gauge) - harness to intake I've also added a grounding wire between the body and intake (10ga) - however these all seem to be unrelated as it is only the ECU pin 5 to ground circuit where I am seeing resistance numbers.

Well I took a look, they are very different components. Most strikingly the turbo one has two additional pins (A-B-C-D versus A-B-C-D-E-F). The non-turbo is SPFI so maybe that's the problem. I am going to try some other stuff like cleaning grounds before I do the replacement but if anyone has seen a turbo or MPFI (would that include loyales?) in a bay area junkyard recently I'd like to hear about it... Thanks, -Hamish

Hey y'all - I recently picked up an 88 Turbo GL wagon to replace my ailing 88 GL Wagon. The Turbo runs generally fine but has been giving me some odd stalling problems which the ECU is diagnosing as a bad Airflow meter. Disconnecting the plug let me start the car and drive it but it was in failure mode and obviously performance was poor. My question is, seeing as how I have an 88 GL with an engine which works fine, can I pull the Airflow meter from that, or is there a difference for the Turbo version? I haven't inspected them side by side yet, but in theory seems they could be the same since it is before the turbo. Anyone have relevant experience here? Thanks, -Hamish 88 GL Turbo (Javier) 147K 88 GL (Pedro) 263K

Actually the 51 means there's never continuity - the switch is broken or the wire disconnected. What I found is that the plastic nub which triggers the switch can actually wear down. I think the internal contacts may get corroded too. I pulled a few in the junkyard and picked the best one - they are all kind of flaky. I believe my fuel economy actually went down with the fix - makes sense as you would think an idling car would back off the fuel curve. The nice thing is that it also loses that surge I referred to in an earlier post.

Well I spent the better part of the day in the junkyard, but it looks like this one is solved. We'll see if the CEL comes back on but tentatively, looks good! I was fortunate to find that the neutral switch is actually located for reasonably convenient access from below the car. The hardest part is getting the wires/harness accessible as it is held down by a metal bracket that must be bent up so the wires may be removed. The neutral switch is near the back of the transmission on the driver's side. It is best identified by looking for where the shifter rod enters the transmission. The neutral switch is about an inch from the end, directly in line with its stroke. There must be some detent which is triggered in neutral. It can be removed with a 19mm wrench. The switch lever itself is made of plastic which may explain the reason it failed. Over time, the plastic nub wears down and does not fully engage. If you pick up a junkyard one, make sure it is not too worn. I took my multimeter to the JY and made sure it had good continuity when car was in gear. Kragen and other parts houses don't have this on the books, so if you want one new it is probably a dealer part. I found one on an 86 GL and two others on a 91 and 93 loyale, so they are not uncommon. The quality of the contacts was pretty varied, which is why I picked up 3. If the problem is simply the worn nubbin, you could maybe build yours up with JB weld or epoxy. Nice to be finally free of error codes. Hope this helps the next lucky sap in my position. -Hamish 88GL "Pedro" 248K

The harness was from a California Manual. Mine is a 49 State manual. The difference is some sort of EGR control, so my harness now has an extra unused connection for that EGR valve. I had to modify the harness (pull a couple pins) to make it similar to a 49-State harness. The ECU was giving me a "bad EGR" code until I did that. I was getting the code 51 even before the harness swap, so that makes me suspect the problem is unrelated to my harness swap, which solved the other problems. Any chance you know more specifically where the neutral sensor is located on the transmission?

What makes me pretty sure that this is the problem is that when I adjust the throttle sensor so that pins A and B are never connected, the problem goes away. This is presumably because it never gets the cutoff signal. It idles smooth but a little high adjusted this way, whereas it idles about 200 rpm lower with what I'll call the "cutoff" circuit adjusted to kick in. Subynut, I don't know the total context of your issue but before you take the drastic step of replacing the throttle body, you might just try adjusting the TPS so that the top two pins (A and are not connected, even with the throttle fully closed. According to the Chilton manual, the proper adjustment is for them to be in contact at full close, but not at full open. Subynut, if you're getting the same code as me (51), this might be your problem too. Course this may be a case of the blind leading the blind

Reading this again I realize this sounds a bit silly - of course the fuel delivery is reduced with a closed throttle but this is a noticable switch - as if the car had died. It's enough to throw you forward when you hit the threshold. This is the point at which there is continuity between the top two pins of the sensor so the ECU is obviously interpreting this as time to conserve fuel. -H

Thanks for the compliment - I have to credit the first two owners who were meticulous about maintenance. I really lucked out there. A little backstory here: When I bought the car the check engine would intermittently flash several codes - primarily one which indicated a broken throttle position sensor. After replacing it several times over with junkyard units, I began to think the problem was something else. Indeed, there were some splices in the wiring harness I had never quite figured out, since the wiring was otherwise completely stock. Appears that the harness was determined bad at some stage, and someone had tried to bridge the bad section. Maybe it worked for awhile but it wasn't working now. I found a junkyard engine harness and the codes went away, save one - code 51 for neutral switch. Making some adjustments to the throttle sensor position, I found that when properly adjusted, there was a noticable flat spot when the throttle was shut. It's clear that when the throttle is shut, the fuel delivery is significantly reduced. Enough to be really annoying in traffic because it causes a sudden clunk of decelleration. My theory is that a properly functioning neutral switch will avoid that - if not in neutral then no sudden fuel cutoff. Other than that I have not noticed any loss to drivability, save running a bit hot/lean at fast hwy speeds. It's possible that the neutral switch is reducing the fuel at these speeds too, which would explain the lean condition - however I haven't ruled out the fuel pump yet either. Both the search function and the related links have been of limited help to my specific question - they are generally focused on the newer cars or the automatic transmission neutral switch. My fallback plan if nobody knows is to hit the junkyard this weekend and pull one apart. I'll update the post for the next poor sap if I find the answer. -Hamish

Hi folks - first post. The board has definitely been a resource however, I've used the search function for several months now to keep my car up and running. Thanks for all the shared knowledge. I'm getting a code 51 on my 88 GL 5spd. I've fixed the other codes and this is all that's left. I don't have a good manual that tells me the location of this switch though. Has anyone made the replacement that can give me some advice? Is it the same as the reverse switch or are they two separate pieces? Approximate location on the tranny? What sort of work is required to remove and replace this piece? Thanks! -Hamish 88 GL - "Pedro" 248K