bmcgawain Posted October 21, 2011 Share Posted October 21, 2011 Omg. I am getting hacked. So if you have followed any of my post then skip to the next paragraph. For those that need the details, here you go. I replaced my original engine with a used engine from Texas. (supposedly a JDM) whatever. Either way I used the original tb, intake and lower plenum. I didn't trust the used one. Looked full of dirt. So the perfectly working upper end of the vg30i came off the original. Worked when the head gasket blew (no rebuild as the heads cracked and I couldn't buy a head for a 1/87), but it didn't work after I installed it on the replacement. The engine idled and ran great except it would not rev past 3,000 rpm. No matter what. I actually drove it 200 miles this way. Nothing changed. No biggie I thought. I checked the ECM trouble codes and found a 12 and a 43 (I think that is right). Basically MAF and heated O2 sensor. Whatever. So I tested the MAF through the on board diagnostics and it failed. So... Then I bought another MAF from a guy on here and it was a known good sensor. The sensor looked great and when I installed it it changed my issue. Now instead of not being able to rev past 3,000 rpm, it idles like a beast. It also chugged black smoke like crazy. I let it warm up and it started to get a lot better. I thought maybe the ECM just needed a minute to clear up. When it did I took it out for a test drive. It ran beautiful! Full power, redline and all. I could smell that it was running rich, but hardly and black smoke. Only at high rmp. But half way home it all changed. Instantly it went back to not being able to rev past 3,000 rpm and before I knew it the only way I could get it off idle was if the clutch was disengaged. Neutral it would misfire and sputter to 4,500 rpm, but under a load it had zero power. Not even a little. Then it started to die and chug black smoke on start up. Then it was back to the loping idle and black clouds of smoke. A lot of useless details here I'm sure, but I thought it wasweird how it got better and then worse. This all just happened so I haven't checked the ECM for any codes yet. Anyone seen this happen to their rig? Maybe you have some suggestions for a guy tring to drive this ole' 87 home soon? I will post any new findings tomorrow morning. Hopefully this is common enough to pinpoint the issue without me losing my temper and posting the whole thing in the for sale section Link to comment Share on other sites More sharing options...
sewebster Posted October 21, 2011 Share Posted October 21, 2011 Well, check the codes... maybe your o2 sensor is busted, though it does sound pretty bad. Link to comment Share on other sites More sharing options...
craftsman67 Posted October 21, 2011 Share Posted October 21, 2011 I have been having VERY similar issues for the past few months, and it's been driving me nuts also! After 2 new MAF's, (1 after market, 1 OEM) and about $500 in various trial and error parts, I now am getting code 43 (injectors)...I found this check that I am going to try after work tomorrow. It might be worth trying??? Here is the link if you want to give it a shot. http://ww2.justanswer.com/uploads/heavychevy396/2010-11-16_221619_1986_nissan_d21_rough_idle.pdf Hope it helps, Scott. Link to comment Share on other sites More sharing options...
Slartibartfast Posted October 21, 2011 Share Posted October 21, 2011 Given the truck's age and the fact that you've been moving the wiring around hooking up the motor, maybe there's a bad connection. Plugs, continuity, probably worth a check. The MAF might've been fine, just undoing the plug scraped off enough corrosion for it to run right for a bit? Seeing as it's worse than before though I doubt it. You say you were pushing it a bit before it started running horribly. Craftsman says he has the same issue and an injector code. Perhaps you've got an injector issue also: while driving it in 3k failsafe mode, it didn't get a lot of sloshing in the tank, right? Dirty gas or whatever collects at the bottom. Then you start pushing it harder, it sucks some crap through, and it gums up an injector? The resulting misfiring etc might've put it back into failsafe mode even if the MAF's okay. (Check the fuel filter first?) Link to comment Share on other sites More sharing options...
JamesRich Posted October 21, 2011 Share Posted October 21, 2011 Since it ran good before and hasn't since you installed the new motor, I would check your wiring harness. Make sure you don't have a pinched wire between the bell housing or under the intake or throttle body. Next try the service bulletin craftsman67 posted. I ran this test on mine to make sure both injectors were working and it ran alot like you are describing. You could have a problem with the plug for the injectors. Also releasing the red and green wires from the connector is a real pain in the ass so good luck with that. James Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 Well the checkin of the wires sounds plausible. I'm gonna give this another shot since it's free. I have a can of corrosion cleaner that I am gonna blast into every connector. Then I am gonna use a nylon Brodsky brush to clean all the terminals. Inspecting these all before I reconnect. As far as fuel goes I filled the tank with 91 premium and then I added a fuel treatment. I changed te fuel filter at that time too. I guess I did crank on it before the filter change, but I wasn't really that bad. I've seen worse working at the Nissan dealership. Some have gas that's brown like mud when you change them. Either way I am dedicating today for repairs. Appreciate the suggestions. Keep them coming. Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 (edited) FYI, auto correct pisses me off. Anyone ever heard of a brodsky brush?! Lol Edited October 21, 2011 by bmcgawain Link to comment Share on other sites More sharing options...
RJSquirrel Posted October 21, 2011 Share Posted October 21, 2011 (edited) FYI, auto correct pisses me off. Anyone err heard of a brodsky brush?! Brissel I have heard of a bristle brush. Don't know about the other two, though. Is it possible the distributor wasn't tightened down and has moved? Severely retarded timing would cause black smoke too. Have you replaced the O2 sensor per the code reading? Did you lose a tooth on the timing belt? You did install a new one before you installed the new engine, right? Edited October 21, 2011 by RJSquirrel Link to comment Share on other sites More sharing options...
sewebster Posted October 21, 2011 Share Posted October 21, 2011 I hate that 180 degree problem. Mine backfired in the exhaust and blew up a brand new muffler. Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 Yeah I'm not going to swap in a used engine and be a retard. Timming is gravy. Like I mentioned before. Ran perfect with old MAF, just wouldn't rev. Timming was and is still set to 12 degrees btdc. I'm suspecting the few input sensors on this engine. O2 is a likely culprit, but I am looking into the cylinder head temp sensor as well. Tps checked good and my MAF is good. Not much left to check. Link to comment Share on other sites More sharing options...
Kingman Posted October 21, 2011 Share Posted October 21, 2011 (edited) 91 octane: not good, it'll probably run worse now. Always run 87 as that's what the engine was designed for. Anything higher and the engine has to work harder to burn the fuel. If an injector were clogged it usually wouldn't spray any fuel at all, right? Not so much fuel that it barely runs and blows out black smoke. But maybe one is just stuck open? I'd test your CHTS if you find the injectors are both good. The sputtering and black exhaust while barely running sounds exactly like my issue I had a long time ago. The truck had to be towed because it wouldn't run anymore, it fouled the plugs completely, and ruined my catalytic converter. I forget what the ohm reading was but it was so rediculious it worked out to the ECU thinking it was -913156 degrees when it was really a 65 degree day. Definitely check wiring as well. The CHTS and MAF are grounded together. One bad ground could throw both sensors way off. Also periodically clean your plugs if you aren't already. Keep them clean so they don't foul and change the problem you're already having. The o2 sensor only comes into play above 2,800RPM for cruising. Below that everything is running off the other sensors. You could try unplugging it and see if anything changes. The engine shouldn't run any different, I've driven mine 200 miles with it unplugged and lost maybe .5MPG on the highway. Edited October 21, 2011 by Kingman Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 A higher octane fuel I don't think would matter. If anything the more pure refined product would burn more complete and burn easier. That's why a forced induction requires it. Lean condition would be the result if it were causing the problem. And lean is mean, right?! Link to comment Share on other sites More sharing options...
Kingman Posted October 21, 2011 Share Posted October 21, 2011 (edited) A higher octane fuel I don't think would matter. If anything the more pure refined product would burn more complete and burn easier. That's why a forced induction requires it. Lean condition would be the result if it were causing the problem. And lean is mean, right?! Octane is resistance to burning. 91 contains no more energy than 87, actually less. That's why turbo cars and higher compression NA engines use higher octane fuel... so they can push more energy (boost), advance the timing, and get hotter without detonating. For example, on my '87 Z31 turbo with a 7.8:1 CR engine and 7PSI of boost. 87 octane was MORE than sufficient for this and it ran much worse with 91 octane (made it gutless). The stock Pathfinder CR is only 9.1:1 and a VG34 with a 10.xx:1 runs fine off 87 octane. If I ran 10PSI of boost in the Z, then I would need higher octane fuel because more energy from the turbo means more heat to detonate the fuel. Yes, lean is mean. Edited October 21, 2011 by Kingman Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 So back to the ECM and I pulled another code 12 MAF. Then I put the ECM in diagnostic mode number 4 and checked the tps. Absolutely nothing happened. No red led. So does anyone have the wiring schematics to test this? I saw a downloadable service manual link, but I am mobile Internet only. Sadly on an iPhone too. Not good for PDF files:( (I know there are apps and all that, but another day) Anyone know the specs on that tps? Link to comment Share on other sites More sharing options...
RJSquirrel Posted October 21, 2011 Share Posted October 21, 2011 If you have a completely misfiring cylinder (bad plug/wire/cap) you'd be dumping raw fuel and air into the exhaust, which would cause the computer to see a lean condition, and richen the others to compensate. Since it cant compensate for all the unburnt fuel, it might think the O2 sensor is out of range. The computer would eventually go into failsafe, and this would explain your smoke and lack of power. Link to comment Share on other sites More sharing options...
sewebster Posted October 21, 2011 Share Posted October 21, 2011 Are you sure you have the right code table for an 87? Someone just posted the other day that they were different for the very early years... If it is a MAF code again, then you either have a problem with your maf sensor (again) or the wiring between it and the ECU... Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 Ok, here is the update. After replacing that MAF. So I went back to the trouble codes and pulled that code 12 MAF. So I cleared it and moved on. Code has not came back on since. Next I went through all 5 test modes and I found that in test 4 the tps failed. No red led. So I pulled the connector and found 2 out of 3 pins to have green crusty corrosion. Cleaned and routed wiring in a less binding way than before. Next I went to crank engine and I'm at a crank no start. WTF?! So any guesses now? Maybe someone can look up voltage specks for me? That would rule. Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 Are you sure you have the right code table for an 87? Someone just posted the other day that they were different for the very early years... I'm using the ones pinned in the how to section. I do have a 1/87 pathy, but my engine and computer are out of a 3/89. That's all I know Link to comment Share on other sites More sharing options...
sewebster Posted October 21, 2011 Share Posted October 21, 2011 Codes are probably right. I don't even think the TPS is involved in starting the truck? Sounds like you have a bunch of different stuff going on... really hard to diagnose unfortunately... if you can't start the truck I'd probably work on that first... back to basics, spark, fuel, air Link to comment Share on other sites More sharing options...
bmcgawain Posted October 21, 2011 Author Share Posted October 21, 2011 Spark and fuel are there. I'm still suspicious of wiring or shorting. But I really need to check this tps. No where online can I find the specs for that either Link to comment Share on other sites More sharing options...
JamesRich Posted October 22, 2011 Share Posted October 22, 2011 If you are using the 89 ECU with the 87 wiring that could be giving you a problem. I'm not sue if the wiring is different but the ECUs are. Here is the trouble shooting pages for the TPS from the 89 D21 FSM If you want a copy of the 89 D21 FSM PM me an email for a link. The only thing I have on 87 is a hard copy. If I get time this afternoon I will sit and compare the ECCS wiring schematics to see if the wiring is the same for the 87 and 89. James Link to comment Share on other sites More sharing options...
craftsman67 Posted October 22, 2011 Share Posted October 22, 2011 Mine is also an 87, and I was also going by the code #'s on this forum, until James pointed out that there are some different code #'s on the 87, than on some others years. I saw on your original post that you thought it had a 12 and 43 code...On the 87, 43 means 51 (injectors),in the 89 FSM. I was able to determine that I have a bad injector, using the thread I posted earlier, after also replacing the MAF...I'm really thinking your problem is the same as mine. I am really hopeful that I have my problem figured out...damn things aren't cheap though...Oh Well,,, Whats another couple of hundred bucks??? Scott. Link to comment Share on other sites More sharing options...
sewebster Posted October 22, 2011 Share Posted October 22, 2011 He said the ECU was out of an 89 though... Link to comment Share on other sites More sharing options...
craftsman67 Posted October 22, 2011 Share Posted October 22, 2011 He said the ECU was out of an 89 though... Oh...Didn't catch that...just sounds really familiar though. Link to comment Share on other sites More sharing options...
bmcgawain Posted October 23, 2011 Author Share Posted October 23, 2011 If you are using the 89 ECU with the 87 wiring that could be giving you a problem. I'm not sue if the wiring is different but the ECUs are. Here is the trouble shooting pages for the TPS from the 89 D21 FSM If you want a copy of the 89 D21 FSM PM me an email for a link. The only thing I have on 87 is a hard copy. If I get time this afternoon I will sit and compare the ECCS wiring schematics to see if the wiring is the same for the 87 and 89. James The tps schematic is perfect. Thanks! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now