Still running lean Reply #45 – January 23, 2009, 09:52:33 PM Okay, I'm back. After having taken the car to Canada and back, I've found some interesting things. First, the big news. I found that Averaging 63-65mph, I obtained 31.9mpg with the engine is it is over 150 miles that start/end at very close elevation. At 75 I started getting 29.5-30mpg. 80mph I'm getting 28.5mpg. I'm not sure if it was always like this or if my last couple tests weren't complete, but I've had a ton of travel time to find these values as being valid. I was getting 28mpg solid until it seemed out of nowhere I started getting 30mpg on flat terrain. Perhaps the engine's breaking in more now that it's had a good amount of time to run with the oil thinned out, I don't know, but the economy figures I'm seeing are promising. All the above figured are with NO cruise control, just accelerating, then coasting, over and over again. The vacuum from the coasting seems to overcome what losses are taken upon light acceleration - possibly being why I'm seeing the above economy that much higher than when I was using the cruise control. Putting an electric fan back in should give me the same boost I saw on the stock engine also Anyways, with the above information, I'm looking to just smooth out the rough open loop idle and go from there. I'll see what everything shows once I get the tweecer and wideband in there. If that's gone, I can deal with the car for the most part and check out the parts whenever I yank them off again.I also need to look into why my gas tank doesn't seem to vent properly at most pumps. It takes 3-4 fillups to get the fillup amounts accurate to the values the tripminder is showing as burned. Quote Selected
Still running lean Reply #46 – January 24, 2009, 05:17:19 AM QuoteI also need to look into why my gas tank doesn't seem to vent properly at most pumps.Clogged/pinched vacuum to the canister purge system.Quotethe tripminder is showing as burned.????????????? Quote Selected
Still running lean Reply #47 – January 24, 2009, 11:49:15 AM Quote from: V8Demon;253289?????????????Fuel usage reading in the tripminder. Quote Selected
Still running lean Reply #48 – January 24, 2009, 11:52:59 AM Quote from: V8Demon;253289Clogged/pinched vacuum to the canister purge system.The vacuum line going to the canister is new - the line from the fuel tank to the canister I haven't checked recently but the car's had this problem for as long as I've had it. Slight downhill pumps always let me fill it to the top though...otherwise I only get 3/4 tank. Quote Selected
Still running lean Reply #49 – February 07, 2009, 08:34:44 PM UPDATE!Got the TwEECer installed but haven't wired up the DataQ/wideband yet. Anyways, I'm still trying to figure out the logs but the rough "open loop" problem is actually right after it switches to closed loop, and through 30 seconds or so. During this time, the timing is bouncing up and down. I also turned on all drivers/passenger side separate monitoring and found the injector pulse width to be double (I assume one bank?) on one side than the other. This all clears up when the HEGO's both drop for a couple seconds, then come back up and the injector banks both start reading the same (or close to one another).Now I completely forgot about trying to switch the oxygen sensor harnesses around until now so would this cause the above symptoms? I figure I'll give this a try tomorrow as it's about dark and the engine's hot. Quote Selected
Still running lean Reply #50 – February 07, 2009, 08:39:11 PM I was looking through the logs and sure enough, this appears to be the problem - it expecting richening results but seeing them on the wrong sensor. Quote Selected
Still running lean Reply #51 – February 07, 2009, 09:00:18 PM Of course, the grounding wires for the oxygen sensors are keeping the harness from reading the 18" oxygen sensors...*sigh*I'll have to try swapping them tomorrow when I have some light.Anyone have any information on what the EEC is doing during this time other than some type of calibration? Quote Selected
Still running lean Reply #52 – February 07, 2009, 11:22:04 PM One thing I missed was apparently when it cleared up on my datalogging earlier, the car went back out of closed loop?! You can check out the screen at the link below. I fast forwarded through a couple parts of repetitive logging to get the file smaller but the transitions are all there.From what I'm gathering, HEGO 2 is reading lean while it should be getting excess fuel. Also, I have yet to see the car hold (even while driving it) .4-.5v except with large fluctuations - should it not be around 4.3 for 14.7 most of the time?LINK! You only need the Macromedia Flash/Shockware player installed to view:http://home.comcast.net/~seekproj/1.htm Quote Selected
Still running lean Reply #53 – February 08, 2009, 06:53:15 AM I couln't tell you what the voltages would/should be without digging around, but I had a feeling your harness was reversed.Glad you found out I went through this same thing and all the while I had NO codes even in KOER mode....QuoteFrom what I'm gathering, HEGO 2 is reading lean while it should be getting excess fuel.In a nutshell :)Cool Video BTW! Quote Selected
Still running lean Reply #54 – February 08, 2009, 11:44:18 AM Quote from: V8Demon;255882Cool Video BTW!Yeah, the biggest annoyance is only being able to log 16 pieces of data so with logging driver/passenger side pairs, I had to turn off a lot of the other sensors. Quote Selected
Still running lean Reply #55 – February 08, 2009, 07:21:54 PM Swapped the wires and sure enough, the oxygen sensors switch properly now. This last trip when I noticed a sudden change in economy (after pulling off the highway to fillup), it must have been it successfully going into closed loop somehow after getting back on the road. Now I should be seeing solid 30+mpg instead of upper 20's I normally see.The rough engine on warm startup is gone. Quote Selected
Still running lean Reply #56 – February 09, 2009, 05:09:05 PM I've been having very similar problems with a twist. I get the horrid sluggish condition and lean backfire through the intake but no codes. The car acts as you had described your car. I get an odd idle hunt that will stall the engine as it revs down and up so hard. I'll have to look into this injector harness thing. Quote Selected
Still running lean Reply #57 – February 09, 2009, 06:47:58 PM Well this was a quick fix. My Hego harness was installed correctly but while checking this I found the orange Hego ground wire to be loose. I must have forgotten to tighten it when I installed the motor in July, I was in a hurry getting the car ready for Cat Jam at the last minute. After cleaning the ground and the head surfaces and reinstalling I went for a drive. The car drives nearly perfect now. I can tell the car is going into closed loop and not having any issues now. I do still have a 100rpm idle flutter when I come to a stop but it only does it twice, no more hunting until it kills itself. I believe this is happening as a result to my raising the base idle up on the t/b to compensate for the hunting. I'll lower it back down and see what happens.Thanks Paul and Seek, without a problem relation to Oxygen sensors I wouldn't have found this without mucho digging. Quote Selected
Still running lean Reply #58 – February 09, 2009, 08:23:22 PM Quote from: CougarSE;256125Well this was a quick fix. My Hego harness was installed correctly but while checking this I found the orange Hego ground wire to be loose. I must have forgotten to tighten it when I installed the motor in July, I was in a hurry getting the car ready for Cat Jam at the last minute. After cleaning the ground and the head surfaces and reinstalling I went for a drive. The car drives nearly perfect now. I can tell the car is going into closed loop and not having any issues now. I do still have a 100rpm idle flutter when I come to a stop but it only does it twice, no more hunting until it kills itself. I believe this is happening as a result to my raising the base idle up on the t/b to compensate for the hunting. I'll lower it back down and see what happens.Thanks Paul and Seek, without a problem relation to Oxygen sensors I wouldn't have found this without mucho digging.It's amazing how something so simple could cause these headaches. At least mine would clear up as it'd drop back into open loop after the o2 sensors failed to respond as the ecu was expecting...I have yet to have any more problems - it runs great and should do even better once I tweak some things a bit. I get like a single hunt when it goes into closed loop when I'm in park/neutral (which the datalogging shows to be when the sensors both go lean for a second), but doesn't happen if it goes into closed in drive. It's only like 50 rpm's either direction - hardly noticeable. I have to get a new fuel pump in here though as I see 70% duty cycles on my 19lb injectors at 4,000 rpm's - somewhere around the range my stock fuelpump should be cutting out also. I have one coming, along with 24lb injectors/75mm Pro-M mass air sensor which should keep me out of lean up to ~5200 rpm's where I have to make the transmission upshift due to its stock stall converter. Sometime this spring/summer I'll try installing the Keith Craft CNC'd afr165's to get some more timing thrown in. It will be interesting to see what the HO cam will do in terms of a wide power/efficiency band. Gotta keep that economy up as gas will be $4+ a gallon again before we know it. Quote Selected
Still running lean Reply #59 – February 09, 2009, 09:59:46 PM While I would drive down the road and the car would start to stumble if I started to give it gas it would go back into open loop and run fine again.. and repeat for the entire drive. I'm running a very similar combo to you. GT40 heads, stock HO cam, exploerer intake.. I am running a 190lph pump. Still on SD though. I've been averaging 25-6 MPG so hopefully I can do better with it running right.My biggest problem is the stock cast iron manifold and the stock split XR7 exhaust.. sans cats. Quote Selected
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