ZR8ED Posted October 6, 2005 Share Posted October 6, 2005 Ok the car is up and running, and I have been getting it to run better and better as I work harder on it. Ok new update. I have since added a helper spring to the turbo wastegate, as I could not get more than 12 psi (14psi spike) since I have added the 3" exhaust system. Now I can run 17psi and it settles in around 15psi. MUCH faster now. Ok. I'm still only getting 12.5- 13.3 afr's while driving. I can get 11.5 afr at WOT at 17psi. I do notice that in the higher gears, I go from crusing at 13:1 afr to 14:1 as I roll up to WOT, at which point the afr's go to 11.5:1 and all is good again. I still have a on/off feel with the throttle with in town driving. Someone suggested I am not getting into closed loop/open loop??? I should have very good afr's (14:1) while idleing or just off idle driving. The car feels like it wants to decelerate (17:1 afr) or accelerate (12-13:1 afr) keeping at a steady throttle is no easy, and sometimes the car will chug slightly as I do it. (ie in stop and go traffic and driving slowly in 2nd gear). While coasting the afr's stay pegged at 17:1 till I slow down considerably, and you can feel the car kick in and coast smoother (slowing at a lesser rate..like coasting with the car in gear and then taking it out of gear) at this point, the afr's go to 11-12:1 till the car is slowed down or I put my foot on the clutch to come to a stop. then the afr's go to 12.5-13:1. I'm not too sure what to check to test this out. BTW car pulls like a freight train at 17psi in 3rd! Quote Link to comment Share on other sites More sharing options...
clint78z Posted October 6, 2005 Share Posted October 6, 2005 I would definately try tweak the TPS more since it dictates the low end fueling. Check for small vacuum leaks, they can reak havoc with light load. Keep at it !! Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted October 14, 2005 Author Share Posted October 14, 2005 Well my idle air bypass is definately not working all the time. I started the car yesturday, and the car would not hold idle, it jumped back and forth from 1300rpm to 2000rpm back and forth, back and forth...very anoying. I got out the first tool that I thought would work. My hammer. I lightly tapped on the soleniod, and the idle immediately settled out about normal. I had the idle set before to idle at about 1500rpm cold, and 1000 warm. It has not done this the last 3 times I have driven the car, so something is defineatly up with this idle bypass. I got out and adjusted the throttle plate screw, and brought the idle down to a more reasonable level and took the car out for a run. The car ran MUCH nicer. AFR's are much nicer in the mid cruising range. 13.5:1 I drove it for about an hour and the car ran very nicely. @15psi the tires start to spin in third gear when rolling hard on the throttle to WOT. That is LOTS of fun. I think I'm going to remove the entire idle air bypass and plug the line from the i/c pipe that fed it. What a PITA! Good news though. I am scheduling a dyno date before the car gets put away for winter. I hope to hammer out a time later today. I'd really like to do one or two pulls just to see what it can do, and so I can make plans over the winter to fix what ever needs fixing. Its been lots of fiddling with what few adjustments that I have, and just taking my time that has gotten the car back to running this well. It doesn't appear to have been any "failure" that caused this, other than some bad grounds possibly. I may have been tuning the car with some bad grounds, and now that it is working properly, I've had to retune my settings. At least that is the only reason I can think of for causing this much grief. Quote Link to comment Share on other sites More sharing options...
Clifton Posted October 16, 2005 Share Posted October 16, 2005 Measure the stock narrow band voltage. A bad sensor will keep the afr from staying around lamda. Should bounce around .4-.5v. I lost a wire on mine on the highway and was in the high 10's in cruise. Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted October 19, 2005 Share Posted October 19, 2005 disconnecting your IACV will do wonders for a steady idle... however, whent he car is cold the idle will be barely crawiling, so you'll turn it up and then when it's warm it'll be racing so you'll turn it down, and then when you go for a mountain drive the car will die on idle. The IACV actually controlls idle for different conditions to try to maintain idle. Fuel injected idle just isn't the same as carburated, it's more complicated, but maybe you'll get lucky good luck. Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted October 19, 2005 Author Share Posted October 19, 2005 Well I have a spare unit from another 88 300zx, n/a model. Maybe I should install it and give it a try first? It works fine once warm, it must stick when cold. I few light taps of the hammer does a wonderful job. Must look pretty fun to passersby to see my get out the old hammer to fix my little baby. hehe Quote Link to comment Share on other sites More sharing options...
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