newrider3

Thanks for the pics, that's exactly what I was looking for. Got to the ECT sensor plug (managed to break the egr vac solenoid whilst down there) and probed it for voltage, shows a steady 3.14v both key on engine off, and key on, engine on. Is this the correct reference voltage?

The CEL is back, narrowed down to two codes. First was an O2 sensor fault, attributed to a 'stuck' sensor (no signal change even with drastic AFR changes). I replaced this and saw improvement in the way the car runs, it's probably been running for quite some time without ever getting into closed loop due to the fouled sensor. Next issue is an ECT sensor code. I've been experiencing occasional rich stumble/other hesitation when accelerating and decelerating, as well as an excessive high idle at cold start that never fully drops to idle. I'm having trouble with finding information about the coolant temp sensor and circuitry itself, it seems for each source I try I find conflicting information. The Chilton's diagram shows a single wire from the sensor to the ECU, white/black, while the manual from the link posted earlier in the thread shows it having two wires, WB and BR. From looking at photos of replacement temp sensors and temp senders online, I'm getting even more conflicting info. Here's a couple pics showing what I'm working with: The top of the t-stat housing, what I've been assuming is the temp sensor. The two wire plug matches up, but the blue/black wires don't, and I'm not sure what the sensor is physically supposed to look like. Probing the male side (sensor) gives me resistance readings at different temps matching the ECT specs. Probing the harness pigtail with key on, engine off shows nothing, and I read alternator voltage (~12-14v) with the engine running. Both sides also show continuity to ground (??) so I believe there's a short here somewhere. Pic two is where (what I thought was?) the temp sender was, now replaced by a mechanical gauge sender. You can also see the white/black stripe wire that connected to it (can also see a white/green stripe wire that has been hanging since I got the car, anyone know its purpose?). If I go by the Chilton's manual, it would lead me to believe that this should be the temp sensor rather than the sender, but I don't believe this is correct, can anyone shed some light on this?

Thanks for the suggestions. I have seen no documentation on the car anywhere calling for anything other than regular unleaded, so that's what I've been running. Also, the engine is 100% stock, no wastegate mods or anything to raise the boost.

Yes, I know. Engine was at full operating temp. Funny thing is, right after I posted last I went and started the car again (hot start) and it fired right up, no CEL. Went for a drive and it's running noticeably better (never really noticed the change before). Got back, shut it off, checked the codes again and they were all present. Hooked up both connectors and started the engine, CEL began flashing , unhooked them and the codes are deleted. Seems like a ground or connection problem somewhere is a likely cause. I'll have to see if the light returns, in the meantime I'll do a little digging in the wiring diagram to figure out potential problem areas.

Thanks for the link, very helpful. Can I erase the codes? Following the procedure in the code reading thread from here, hooking up both connectors does nothing. I was under the impression that you can't clear the codes unless the computer detects no faults? Also, I just finished testing the O2 sensor. Key on, engine off, reads .60v. Engine running, it is steady around .58-.59v, I can't tell if there is a true wave function with this cheap multimeter though. Pulling a vacuum hose results in no change.

I've been having some check engine light issues with my '87 GL10 turbo wagon and thought you guys might be able to help me make sense of it. A few months ago I would occasionally get a flash from the CEL along with a misfire/stutter from the engine if I pushed it too hard (~4000 rpm, 10-11psi according to boost/vac gauge) that I attributed to running it too hard with regular fuel. More recently I had the light come on after accelerating normally onto the highway. It stayed on, so I pulled over after about a mile. Aftermarket oil pressure, water temp, and vacuum gauges were all within spec, engine was running great, no abnormal noises. I decided to keep going, and then the CEL was off by the time I got out of the gas station parking lot. Now it came on and has stayed on for a week or two (in college so it sits mostly), with occasional flashes off when idling, or when turning a sharp corner(?). I pulled the codes and this is the results (and some of my observations): 21-ECT (coolant temp sensor) - Tested it with my DVOM and the resistance values are within spec at different temps. The temperature sender has been removed to make room for a mechanical gauge probe, but the electronic sensor is still in place. 23-MAF - The only manual I have access to is the Chilton Online database, and it doesn't list a test procedure for the MAF. Tapping on the sensor housing while idling causes no change, and engine rpm drops severely to a stumbling idle if unplugged. Is there an actual test procedure/resistance values for the MAF on these cars? 32-O2 sensor fault - I haven't crawled under the car to test this yet. 33-VSS (vehicle speed sensor) - The car is lifted with 27" tall tires, so of course the speedometer is way off. Will this even effect the way the car runs, or trigger the CEL by itself? 35-Purge Control Solenoid - Again, Chilton's Online is crap, they don't list a test procedure or even show a picture of this. Any suggestions? 42-IAC (idle air control valve/switch/circuit) - This seems the most suspect to me. Cold starting the car is fine, but it revs up to 2000-2200 RPM then slowly idles down over the course of 5-10 min. Is this normal for warm up? Then the car is difficult to start after a heat soak, I have to hold the throttle WOT when cranking to get it to start. Occasionally after this hot start it will have a severely low idle. I attempted to test this component, but again, Chilton's sucks, and only shows a picture of the IAC for a 2000+ Impreza. So I basically probed every wire off the throttle body for resistance values, and unhooked connectors while idling (no change in idle speed). Oreilly's doesn't even list the IAC in their catalog, so I couldn't get one to look at/price check. Does anyone have a pic of the IAC and it's harness connector so I can see if I'm testing the right thing? 51-Neutral Safety Switch/Circuit - This is obviously faulty, as I can crank the car in gear, with the clutch out, or a combination of both. This isn't a big deal to me (every manual vehicle we own is older and does this), is it a big deal to the computer? Will this cause a CEL by itself? I really have no idea if any of these codes are uncleared legacy codes, and the system won't let me clear the codes until it thinks everything is fixed. Does anyone have any input or suggestions? Thanks!

I couldn't tell you, I just pulled them from the junkyard and threw them on. I think they are a little over stock offset for Nissan/Toyota pickups, they sat a bit wide on the truck I pulled them from.

If someone really wants some part of this car they deem irreplaceable, they can come to my house with cash.

I'm running 235/75 Goodyear Wranglers with my 2" lift. The Wranglers do tend to measure out small though, they measure out to a little under 27" tall. I do rub on full lock turns, and there's some occasional scraping from the rear when hitting a big dip with a bunch of cargo in the back, but I just need to go back and trim the rear wheel opening a bit more.

I'm new to the forums and thought I'd post up some pics of my build. I decided to start looking for a daily driver to save some wear on my project F100. I started looking online at lifted Subarus, and decided to go after one considering the availability and low price in my area. I found this '87 GL-10 turbo on Craigslist, with no asking price. The guy claimed that a piece of the waterpump rattled around in the engine and destroyed it. I was pretty skeptical of this. Called him up and offered $300, and had it on the trailer within the week. Got it to my buddy's shop and started tearing it down. As I had suspected, the engine was just fine. The waterpump seal had given out, leading to the pump bearings giving out and causing huge play in the shaft. A little nick in the block resulted. I threw a water pump on it, and a timing belt kit while I was down there, and it runs great. A little seafoam and a fresh oil change cured the tick of death, it's a smooth and quiet runner for 207k miles. After some reading on here, I built a 2" lift kit and got it bolted together. Next I picked up a set of 235/75/15 Wranglers on some chrome wagon wheels off a Nissan at the junkyard. Drilled the wheels for 4-lug pattern, and threw them on. Did go back and clearance the wheel wells and fenders quite a bit after it settled some. Added some mechanical gauges to keep an eye on things, and built a front bumper out of old oilfield pipe. My initial measurements were a tad off and it came out pretty wide, but I think it works OK, don't really want to cut it up again at this point. And that's about up to date as far as the pics I have, just driving the wheels off it now. I did replace the rusting out muffler with a piece of 2.25" straight pipe (it's still super quiet due to two cats) and the passenger front CV with a locally rebuilt unit. Any questions or comments?