280zxturbo lean out on wide open throttle 370injectors stock electronics

[supernaturalz]

Hi hybridz menbers i need help when i start to open the throttle the air fuel ratio is to rich and full throttle leans out like 13.7 to 14.7 ratio. What could be the problem the car is 280zxturbo 1983 I put new rem. air flow meter , balster  msd coil spark plugs checked new cylinder head temp I, HAVE 370SVO MUSTANG INJECTORS THE AIR FLOW IS ADJUSTED TO IDLE SMOOTH THE FUEL PRESSURE IS 20PSI AT IDLE AND 90PSI AT WOT 255WALBRO PUMP.  PLEASE SOMEBODY HAVE TO KNOW wHAT IS GOIN ON .

[motomanmike]

Not quite sure if your injectors would even open at the right speed at 90lbs of fuel pressure but it might be worth looking into.  Also might want to think about an aftermarket fuel management system to replace the stock ECU. Upping fuel pressure to compensate for the lack of engine management isn't the ideal set up for what you are doing.

[supernaturalz]

thanks mike for the reply Ive been running this set up        for years maybe a little rich with out problems do you think would be a vacum leak  in the intake. an aftermarket fuel system is best way to tune the injection but now i cant buy it. anyway thanks.  

[motomanmike]

Well, there are a few that theorize about the stock ECU's leaning out over time.  Not sure if its your issue or not but there are some threads on it on this site.  Check all your injector wiring at the ECU and also, did the car run better or worse with the original AFM and what was the reasoning for replacing it?  The head temp sensor can play a big role in the mistune on these cars too.  I've read threads about using various resistors on inputs to the ecu to fool it into thinking it was running hotter or colder, getting more or less air etc etc, whatever the ecu uses to decide what to deliver at what time is what they manipulate whether it be with modifying the part or fooling the part into the right reading.  Food for thought.  BRAAP seems to have nailed what you can and can't do with the stock AFM in one of his very long detailed informative threads about the stock EFI system.  They take some time to read but they are a wealth of knowledge about the intakes, the afm's and the various other L series fuel injection set ups.

 

http://forums.hybridz.org/topic/95316-braaps-l6-efi-induction-advice-and-tips/

Edited May 3, 2013 by motomanmike

[supernaturalz]

thank,s motomanmike for the info of Braap I change the injectors for ones  more flow from dsm eclipse injectors but one of then leak and I replace back again to 370ford inj. and you know what i found when I start the engine the wideband aem was at 18 fuel ratio extreme lean at idle missing badly I pull out the chts plug and the idle back again nicely smoooth looking the wide band again now is reading 10.5 too rich idle I, change to another sensor but still doing the same . What is happening is the wires circuit.  How i fix that motoman please replay . And always thanks.    

[motomanmike]

The CHTS sensor has a curve to it depending on temperature listed in the FSM.  This was pulled from the MS install section just outlining the resistence curve of the stock sensor

 

 The Calibration values to use the CHTS are as follows:

14F=9K
68F=2.5K
122F=.84K
 

 

So when you unplug your temp sensor the ECU things its FREEZING COLD outside and dumps massive fuel, hence your very rich idle with CHTS unplugged.  This is what I was saying about using resistors to fool the ECU into what reading it needs to supply the outcome you want.  I am in no way experienced with it with the stock system, I never got my car to run right on the stock ECU thats why I went with MS.  I just understand how it works enough from running Megasquirt.  These are the values of the stock sensor at those temperature values.  So at 14 degrees the sensor if you put an ohm meter on it will have 9k ohms of resistence.  at 68 degrees the ohm meter will read 2.5k ohms.  So you need to figure out how much resistence you need to make your ECU deliver the right fuel so you could go buy an assorted pack of resistors and try splicing them in one of the wires to the CHTS on one lead and experiment increasing the resistance.  Its the only solution I can think of that "MAY" work.  Its a cheap enough thing to try.  Let us know what you find out. Other than that.  I mean at the point you are with the build.  I'd go with a programmable ECU.  If the car was running ok before its probably a corroded wire or bad CHTS sensor possibly a bad ecu with a lean drift.  I know you said you changed it but I went through 3 on my build and all 3 had different resistence readings at ambient temp which can have a huge outcome of how the car runs being the stock ECU is that dependant on the CHTS.  Good luck. 

[supernaturalz]

thanks mike I can use an potenciometer adjustable of 1k and change the resistence. how do Iknow if the ecu is causing the problem I dont have another to try do you think if I put another Efi harness is worth the work    used too.

[supernaturalz]

Why mega squirt and not other aftermarket unit I think is more tunable and easy to install. 

[NewZed]

Get some stock turbo injectors.  With a stock turbo system, 90 psi, and 370cc injectors you should be blowing raw fuel out the tail pipe.

 

Stock injectors and a stock FPR should be a good starting point.  You have a bunch of wrongness going on.

[TimZ]

You have a bunch of wrongness going on.

 (couldn't find an emoticon doing a spittake)

Edited May 7, 2013 by TimZ

[motomanmike]

Get some stock turbo injectors.  With a stock turbo system, 90 psi, and 370cc injectors you should be blowing raw fuel out the tail pipe.

 

Stock injectors and a stock FPR should be a good starting point.  You have a bunch of wrongness going on.

 LOL Very true.  I really shouldn't have said anything about resistors.  Just trying to give him an idea of how the system works to deliver fuel and I think he wants a "DO THIS" type answer and didn't read into the "MAY or MAY NOT" work  which leans towards NOT

Why mega squirt and not other aftermarket unit I think is more tunable and easy to install. 

 

I went with Megasquirt because it was a more affordable option that many others have tried and had success with.  I've never had any experience with any of the other systems but i'm sure they work well.  I swapped an L28ET and never could get the stock system to work right.  It took me a LONG time to get MS to work right but now that it does I have no regrets.

 

I really wouldn't be surprised if this whole thread goes to the shed NewZed

Edited May 8, 2013 by motomanmike

[supernaturalz]

hi motomanmike and new zed I,ve been doing some changes I pull out the chts plug pell the wires from the e.c.u to the plug and change the plug from a 300zxturbo of my brothers car connected back again and yiiiiiiiiiiiiha  the signal of enrichmant back you can see the black smoke of tail pipe at the wide band is 10.5 a little hard to burn in the combustion chambers but with a adjust on the Afm set the air fuel ratio with this set up I race against kawasaki 600 rolling from 50m.p.h to 130 or more because i dont have my speedometer working the bike give me 2 car lenght my one another behind and he can,t catch me the straight street was like a mile or more he stay in the same distance all the way. the guy congratulations for my I win zpower i was 15p.s.i of boost with the manual boost control inactivated. I have another good race with this set  up  yes     i know  this isn,t the  best technology I roll with a corvette ls3 6.2 liter 2008 436h.p. 428torq. top speed 185m.p.h 12.6 quarter mile 116mph we roll from 55 in third gear to 130 or more i saw r.p.m at 6200 in four gear i dont know exactly how much miles i was but im in front of him all the race he catch me at fifth gear. I have to4b 60mm and p.trim 69 housing 3 inch complete the injectors 370 with 90p.s.i increase like 450cc or more.thanks guys for the help.  

[supernaturalz]

All you need to make power is a safe air fuel ratio spark timing and boost good free flow exhaust a good intake cool system big 60mm throttle body. a friend of my with the n/a  fuel injection lock the ignition 20deegres  intercooler 3 inch exhaust hy35 turbo 440cc supra injectors a little of alcohol injection make 420h.p. at the whells26p.s.i with n/a e.cu . I know a programable system is the best way tune an turbo engine. the budget right now is for restauration the body. I believe every info you guys wrote . thanks you are great menbers.    

[motomanmike]

Well have fun with it.  I run 20 degrees fixed at the moment and it works.  Not as efficient but the car runs good.

[supernaturalz]

Hi motomanmike how i do know how much boost i can increase with 370cc at 90p.s.i right now is at 15p.s.i booost.

[supernaturalz]

right now the wide band is at 11.5 air fuel ratio at 15p.s.i to4b 60mm .69 hot side         housing.

[motomanmike]

Well.  Asking for how many LBS of boost isn't the right equation.  A car with a bigger turbo can run 7lbs of boost and be just as fast as your car running 15lbs of boost.  Its all about VOLUME of air, not the psi. A bigger turbo set at 7lbs can flow as much air as a smaller turbo set at 15lbs.   Read up some on turbo efficiency.  I by no means am an expert but know enough that if people ask how many pounds of boost i run i know they really don't understand turbos fully.  Its safer to run lower boost levels, not to mention much cooler.  I wouldn't push the stock set up too far without EMS.  Its already at the edge now.