Guest bastaad525 Posted June 27, 2004 Share Posted June 27, 2004 You know, it used to be that I could get away with cleaning off all my wiring connections maybe once every month or two before the car might start acting funny (seems fine and pulls hard but when it hits 4500rpm at WOT stumbles and looses power bad, I'm assuming going way rich as it backfires as well). Then it dropped down to maybe every few weeks... now it's like... every few days??? So it took a while for my brain to jumpstart and remember that someone here had suggested to put some dielectric grease on all my connections the next time after cleaning them, and I've finaly done so. I'm just kinda stumped as to what could cause the wires to corrode or whatever so badly in 3 days as to cause the car to run like crap... when I look at them there really isn't any visible corrosion, that's the odd thing. But every time I pull them off and clean them the car runs beautifully again. I thought maybe it's not that they are corroded, but maybe just a short or damaged wire or something, but without fail, if I just wiggle or unplug and reconnect them, it doesn't fix anything, but spray them off, and it runs great again. So I put the grease on there this morning, on the ECU, AFM, CAS, and HTS connectors, and am HOPING this keeps this problem. I'll take some time later and do all the fuel injector connectors as well. Gonna really suck if it happens again... then I"m gonna have to clean all that grease off Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 30, 2004 Share Posted June 30, 2004 OMG I was just going to post almost EXACTLY the same thing! My recent experience coincides 100% with your findings. Disconnecting and reconnecting does nothing to improve the rich running and choking. Cleaning the AFM, ECU connectors, and pins with spray cleaner (brake cleaner in my case) will buy me about 2 days of running extremely well. There is a NIGHT and DAY difference in power and driveability after cleaning. However two days is NOT acceptable. PLEASE let me know how the grease worked out and what kind you used. I actually have a friend at IBM doing some research for me. I challenged him to find some magic "stuff" that will allow connectors to maintain a low resistance coupling. OMG I did post almost exactly the same thing. Well, lets keep this up to date. Obviously, connectors are the bane of the hybrid Z. BTW I had posted about using dielectric grease on some of my connectors and grounds a while back. However I have heard that the low voltage we have in our connectors may be affected by a grease. Dave Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 30, 2004 Share Posted June 30, 2004 Oooh look what I found....thanks to Google. http://www.machinedesign.com/ASP/viewSelectedArticle.asp?strArticleId=56604&strSite=MDSite Im gonna try to get some. I requested a sample from here: http://www.nyelubricants.com/ Quote Link to comment Share on other sites More sharing options...
Sean73 Posted June 30, 2004 Share Posted June 30, 2004 Have you tried this: when the rough running starts, unplug the AFM , and use a voltmeter to look for shorts at each pin. If you find continuity between any of the pins, you have a wiring harness problem. Also, check operation of the TPS (check continuity) and CHTS (verify resistance w/manual) from the ECU side of the harness immediately after the rough running. If you're having to clean connectors every other day, I would suspect that the cleaning of the connections only solves the problem coincidentally, because you have to disturb the wiring somewhat to clean a connector. If you have a short, then sometimes simply moving the wire a bit will fix the problem, until engine vibrations and heat bring the problem right back. I assume your cleaning the connections thoroughly, so it would seem unlikely that a connection could corrode enough in a matter of days to the point of failure. Also, it helps if you can narrow down the problem to a single connector. It's unlikely that all the connectors would go bad simulataneously and require cleaning. Clean one at a time and see what improves the rough running. Once you can isolate the problem, you can splice in a new connector that that location. I had a similar problem with my Z31 ECCS harness. Turned out to be the MAF connector, which also shares a wire with the CHTS. The car suspiciously ran better with the CHTS disconnected. The MAF harness was shorting the CHTS and causing the car to run poorly. When I put in a new MAF connector, the problem disappeared. Sean 73 240ZT, L28ET, T3/T04E, NPR IC, Z31 ECCS Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted June 30, 2004 Share Posted June 30, 2004 cygnus - night and day is the perfect phrase for it... Sometimes the running will degrade slowly, and I"ll think I'm imagining it... but day by day the car seems to respond less and have less power, this will be most noticeable during driving before the motor is warmed up. Then within a week that 4500rpm 'brick wall' makes itself apparent, clean the connectors and the car runs fantastic and never ceases to put a smile on my face on that first 'test drive' after cleaning them! So far the dielectric grease seems to be working... I haven't had to clean the connectors since I posted this, and there has been no sensation of the car slowly getting worse... so I'm guessing that this stuff is doing it's job. The car is running fantastic, better than usual I'd say... so I doubt the grease is causing any kind of problems with the low voltage. I picked the stuff up from the local electrical parts supplier, it's called Luberex by GC Electronics. Sean - I haven't tried any of that recently. I did test the AFM not too long ago and found nothing wrong with it. I dont own my own voltmeter though so I dont usualy think to try that stuff. I will say, I dont BELIEVE it is any kind of problem or short in the wiring... as you state, odd shorts like that will often times seem to magically dissappear by simply moving or wiggling the wires in question. Again, with this problem, when the car stars running bad I can disconnect, reconnect, and wiggle the heck out of all the connectors and it will not improve the situation at all, but, clean them off and EVERY TIME, the problem goes away. Usually stays gone for quite some time, a month or more, only lately has it been happening much more rapidly... which I'm puzzled by. Since putting the grease all seems to be well... I'll keep this updated if it happens again (gonna need to vent I"m sure as I'll have to clean off all that grease... gonna be pissed). Oh and by the way, I'm 99% sure it's the AFM connector that is causing the problem, if not then it's a connector on the ECU itself for sure. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 30, 2004 Share Posted June 30, 2004 bastaad525, Very True, wiggling and or disconnecting and reconnecting does NOT work. Cleaning with a solvent does. It is NOT a "maybe" difference, it is a HUGE difference. Last time I had the "stumbles" or "brick wall" I only cleaned the AFM and the three ECU connectors to solve the issue. Next time I will do only the AFM to try to narrow it down. If it is the AFM connector I will be happy because there are only four pins to deal with. I could probably use a conductive paste, carefully, on those four pins and then put some dielectric grease on the body of the connector to keep out the weather. Beating this problem will be a huge milestone in my book and I am sure yours too. We will beat this if you havent already. Quote Link to comment Share on other sites More sharing options...
Jersey Posted July 1, 2004 Share Posted July 1, 2004 How are you guys cleaning the connectors? Sounds odd that it only takes 2 weeks for the problem to arise again. I'll keep thinking. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 1, 2004 Share Posted July 1, 2004 I have been disconnecting and spraying the connector and the pins with brake cleaner which is the same as electrical contact cleaner. I have then reassembled them dry. All the stock connectors and clips are working and are in good shape visually. My friend is bringing home a spray from IBM that is a cleaner/lubricant/anti corrosive and it helps maintain low resistance connections. They use it for millivolt connectors and contacts on old oscilloscopes. The problem is that the stuff is no longer manufactured and he cant even leave me the can. I can use it but he has to bring it right back. I will report on it. I too find it odd. An engineer or common sense will tell you that it doesn't make sense that a connectoin can degrade consistently in a few days of normal use. I too would point to some underlying issue but the fact remains that after spraying with cleaner the car runs ALOT better and then begins to degrade over a few days until it is virtually undriveable. Very strange indeed. And the fact that at least two of us on opposite ends of the country are simultaneously experiencing EXACTLY the same problem makes it even stranger. So far grease on the connectors seems to be helping bastaad525. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 2, 2004 Share Posted July 2, 2004 One thought I had, and this was stupid of me to do but I didn't see how it would have caused any harm, was that, the last time I cleaned them (the time that it only lasted 3 days before f'ing up again) I did NOT wait for the cleaner spray to dry before reconnecting everything... I was in a rush to get to work, and I figured, the stuff being non conductive, wouldn't cause any shorts or anything, which it didn't. BUT, despite teh fact that the can claims it leaves no residue, I have noticed several times that it CAN leave some, and I think this is what happened. Of course, I'm probably wrong I'm now going past one week with the dielectric grease on there and I notice NO degradation in the running quality at all... seems to be holding up great. Quote Link to comment Share on other sites More sharing options...
Guest 2slo4u Posted July 2, 2004 Share Posted July 2, 2004 Has anyone tried soldering the connectors? I live in Louisianna and it is humid and hot 99.9% of the time and that makes everything corrode quicker. I got tired of worrying about clean connections a long time ago. I've soldered all connections under the hood except for non engine related ones (a/c, etc...). This will rule out wire connections as the culprit to your driveability problems and save you a LOT of time and stress. Try and let me know. Soldering is a no brainer for me, I have to use it every day at my job. Good luck and prepare to shed some stress, bruthas! Quote Link to comment Share on other sites More sharing options...
aarang Posted July 2, 2004 Share Posted July 2, 2004 There is a product that is made by LPS. It is called "CFC Free". It is a purpose made electro-contact cleaner. I use it at work almost everyday. The older airplanes I work on seem to have the same connector gremlins as the Z. I know from first hand experience that the older connector pins that are not coated with gold or some other non corrosive can degrade really fast and cause all kinds of problems. I would be wary of using brake cleaner as it may cause oxidation of the connector pins. I think Napa carries LPS products. Hope this helps. Aaron Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 7, 2004 Share Posted July 7, 2004 So far so good with the dielectric grease. I drove the car last night for the first time in a week (that makes it about two weeks since I applied the grease) and it ran great, no signs of any connection problems. I think that's a good sign as it always seems to develop those problems in particular if the car's been sitting for a while... so I hope I"m not speaking too soon but it really seems this stuff if helping. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted July 7, 2004 Share Posted July 7, 2004 You can try Dow Corning DC4 Silicone Grease - That's what I use on helicopter cannon (electrical) connectors. The machines that I work on go offshore, which is the worst enviroment you can expose a helicopter to (well - apart from flying around Iraq). It does a good job of sealing the connection from everything, but don't get it on any surface that you'd ever want to paint. You can also get a fine stainless steel brush to clean out the connectors with contact cleaner. I second Aarons recommendation on LPS contact cleaner - CFC free or No Flash are the only ones we use. Brake cleaner can be very hard on plastic parts - makes them very brittle. I don't think that you will get away with using that for long. I have been replacing AFM, CHT, Injector, and TPS connectors on Z31 harnesses for a while now. It seems that Nissan cheaped out on the material in the connector. The Snap-On guy got me sheets of the crimp on connectors that replace the OEM ones - I tin the wire with solder, crimp the connector on and then heat it a bit to flow the solder onto the connector. This takes care of the connector/wire corrosion problem down the road. Clean the connector after soldering with contact cleaner and a brush to get rid of the flux (corrosive) and then brush a coat of DC4 onto it. Just don't glob the solder on with a 75watt iron as it will wick up the wire and make it very brittle. Some wires I've found in Z31 AFM harnesses have corrosion about 6 inches up inside the wire. Sorry - A little long-winded today Doug Quote Link to comment Share on other sites More sharing options...
Guest 305240 Posted July 13, 2004 Share Posted July 13, 2004 About a month ago, my 81 turbo gave me a scare. I was just going to take it out and blow the dust off it as it had been setting for 2 weeks. It ran fine untill I got up to 3200 rpm then it would cut out and almost shut down. I made it home, cleaned all the connections on my ECU, injectors, ect with a product called DeOxit. This stuff was made for cleaning corrosion off electronic contacts in computers, ect. Anyway, after cleaning everything, I took it out and what a difference! It runs better now than when I got the car! Here is the web site for the stuff. A can should last you for 5 years at least. http://shop.store.yahoo.com/imperialguitar/cables-accessories.html Quote Link to comment Share on other sites More sharing options...
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