Brad-ManQ45 Posted September 16, 2005 Share Posted September 16, 2005 I would not unplug the EGR, I would use a plate of some sort to block off the exhaust from entering the intake manifold. Someone did that to my '83 ZXT with a piece of tin can top under the gasket. Probably when I had the T3/T4 and exhaust added. They said they had some 'tricks' to get more power.... Simply removing the vacuum from it won't tell you anything. Remember, I am talking about the EGR valve sticking open causing a rough idle here. If you block it off totally (not messing with vacuum lines), then you have completely eliminated it as a problem. Up to you to leave it that way... Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted September 16, 2005 Author Share Posted September 16, 2005 Brad. I unplugged the wires that go to my egr. (two) The egr itself was not disconnected. It has been in factory condition since the vg swap. I did install a brand new egr at that time. Today if you start it, it idles smooth at 1300.. warms up slightly and settles in at 1000rpm. 20 inches of vacuum, and (11.5:1 air fuel ratio now that I cleaned the connections on the dizzy) I'm going to pull off the tps tonight and replace it with another used unit off my running 88 300zx. I just bought the 88 na today. I'm going to see if the wires are wet on the air fuel monitor and see if that is a problem. What the problem was before is non existant at the moment. now I'm dealing with a full rich reading at idle, and all throttle positions...the ecu is getting a wonky reading from something... I can check the ecu connections tonight as well... heck maybe there is a hole in the body there and water got to it???? It seems awful sudden for this to happen.. runs perfect for an hour. stop the car.. start car in rain 10 min later, car runs at 11:1 air fuel all the way home, and the next day after everything dries up. and it reads full lean under no throttle deceleration... nothing in between..... Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted September 16, 2005 Share Posted September 16, 2005 Kewl that you are able to eliminate the EGR as a problem. Had a friend that had an idling problem and this was it. Didn't mean to harp (if that's what it sounded like), and didn't have all the info from your last post, so I decided to explain in detail, not knowing your level of expertise, and to help anyone else in later searches. From what you're saying it acts like (rich at all rpm's), sounds like it could be the CHT sensor.... Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted September 18, 2005 Author Share Posted September 18, 2005 Well I'm screwed. no more time.. Car still not running right. I checked some more things tonight. The only thing that had an effect was wiggling the main harnes connector to the ecu. The right hand side of the ecu (looking at the 3 connectors on the side of it) I wiggled it, and the air fuels jumped back to 14:1. Wiggled it the other way... 11:1. I repeated this 10 times, and the air fuel monitored read the same thing each time... So I cleaned the terminals and used some dilectric grease... Car still runs the same way, and now when I wiggle the main harness connectors, the car doesn't improve!!!! So I either cleaned the connectors and gummed it up worse, OR I made the connections better, and one or more of the wires are making better contact and still giving the ecu bad signals..... I unplugged the cyl head temp sensor... no noticeable effect I unplugged the dizzy harness.. car stalls... hehehe unplug idle control no effect idle up control.. no effect I unplugged the second connector from the TPS.. no effect..though I think that is left over harness from the automatic tranny that the harness came from. I cleaned the main tps connector, and reset the tps settings. no improvement. though it did run worse when the tps was not set correctly. I pulled spark plug wires.. car only got worse. What the frig is making the car run pig rich? what should the temp sensor do when unplugged? it is a major pain to get to the sensor..looks like the timing belt covers have to be removed as well..... I think my next step is to sort which wires are what that plug into the ecu, and CUT off ALL the wires that do not go anywhere... maybe there is a short somewhere, and the ecu is getting a bad signal from a wire that is connected to nothing needed... SOOOOO it looks like I have 4 Z's.. All four start, and can move under their own power, and I have to take my Honda to a major Z car event. yeeeessshhh. Outa time..... AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted September 21, 2005 Author Share Posted September 21, 2005 Well letting the car dry out didn't help. It has been sitting for three days now.... Started it up.. still idles at 11:1. I've been busy parting out an 88 300zx this week and have not touched the 280 other than starting it up to see if it ran better. Anyone have a good pic of the wire connectors at the ecu side. I have an fsm, but I don't think it is laid out very easy to follow. anyone have a labeled pic? I'm going to start removing wires from the harness tonight. I'm going to try and locate and remove all wires from the ecu that are NOT being used or needed. I'm going to get Medieval on this car. Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted September 22, 2005 Author Share Posted September 22, 2005 That darn "while i'm at it syndrome"!!!! Ok I got Medieval with the car today. I unwrapped the entire harness. Checked most of the sensors according to the fsm. O2, tps, maf, chts, egr, and cold idle up. seems ok so far. Removed about a dozen wires no longer used or needed. Removed about 5 poor grounds and redid them Removed the poorly functioning idle control Removed the wires and connectors from the tps to the auto tranny (harness came from an auto tranny 300zxt I have been regrouping the wires, and custom fitting the harness better for routing and length. This should have been done a long time ago. I've been working on one thing at a time. I have varified that the car still starts and runs after all of this work!! yeahhhh! air fuels now seeing about 12:1... not sure if it is fixed, getting better or what. I'm sure the car needs a good run to clean up the spark plugs by now. I'm now in the process of neating up the harness, and using all new wire loom covers. It should look neater, and be easier to work on and trouble shoot. I hope! hehehe We'll see after I get back into it tommorow weather permitting. (its raining out now) I just might make it out for our clubs last event...The drag event! One more day to go. Lots to do. been a great day today though! Quote Link to comment Share on other sites More sharing options...
Bernardd Posted September 22, 2005 Share Posted September 22, 2005 I sent you an email with the pinout destinations and purpose. Hopefully that helps out. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.