2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Lean issue when secondaries "kick on"

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Old Jan 26, 2012 | 06:50 PM
  #176  
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From: tulsa,ok.
Originally Posted by -PM-
Yes, I adjusted it by voltage first and then by resistance. There was barely half a millimeter turn between the two
Just a thought but was the engine fully warmed when you did the 1 volt adjustment? And did you switch back to the original AFM? When you replaced the AFM did you remember to connect the hose that goes to the air box? Have you tried just running the car w/the TPS disconnected? And it's probably time to check the fuel pressure.
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Old Jan 26, 2012 | 07:03 PM
  #177  
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Yes, I drove around for a good 20 minutes at least before setting the TPS. I switched back the original AFM because the new one made no difference. Actually after I put the new AFM in, every time I started it, it would idle for 10 seconds and then die.
Haven't tried running it with the TPS disconnected though. Would it even rev?
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Old Jan 26, 2012 | 07:35 PM
  #178  
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From: tulsa,ok.
Originally Posted by -PM-
Yes, I drove around for a good 20 minutes at least before setting the TPS. I switched back the original AFM because the new one made no difference. Actually after I put the new AFM in, every time I started it, it would idle for 10 seconds and then die.
Haven't tried running it with the TPS disconnected though. Would it even rev?
When the TPS is disconnected the ECU defaults to full throttle so it would affect the lower range rpm performance if anything.
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Old Jan 26, 2012 | 07:52 PM
  #179  
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From: Twin Cities, MN
Ok, so I let the car sit for 2.5 hours outside in the cold. It's completely cool. Now it starts and drives like before, as long as I stay in vacuum (no boosting). But at least it idles and I can drive it in all gears, as long as I barely step on the throttle. Take 10 minutes to get to 60mph.

So here's a question: why is it important to let the car warm up to full temp before setting the TPS? Is it because there is a different map for the TPS readings when the car is cold?

It seems like after it warms up for 20-25 min, it starts getting a lot worse (as stated in previous post)....so maybe it is just a bad TPS...?
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Old Jan 26, 2012 | 08:05 PM
  #180  
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From: tulsa,ok.
Originally Posted by -PM-
Ok, so I let the car sit for 2.5 hours outside in the cold. It's completely cool. Now it starts and drives like before, as long as I stay in vacuum (no boosting). But at least it idles and I can drive it in all gears, as long as I barely step on the throttle. Take 10 minutes to get to 60mph.

So here's a question: why is it important to let the car warm up to full temp before setting the TPS? Is it because there is a different map for the TPS readings when the car is cold?

It seems like after it warms up for 20-25 min, it starts getting a lot worse (as stated in previous post)....so maybe it is just a bad TPS...?

Because the fast idle cam interferes w/the throttle linkage when the engine is not fully warmed up and prevents the TPS plunger from being in its true idle position which is necessary to set it. You also might want to check pin 2I of the ECU as it deals w/the Water Thermosensor which helps select how much fuel is used based on the engine temp. Pin 2I should measure 2 to 3 volts w/a cold engine w/key to on and a fully warmed engine measures just under .5 volts w/key to on.
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Old Jan 26, 2012 | 08:12 PM
  #181  
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From: Twin Cities, MN
Originally Posted by satch
Because the fast idle cam interferes w/the throttle linkage when the engine is not fully warmed up and prevents the TPS plunger from being in its true idle position which is necessary to set it. You also might want to check pin 2I of the ECU as it deals w/the Water Thermosensor which helps select how much fuel is used based on the engine temp. Pin 2I should measure 2 to 3 volts w/a cold engine w/key to on and a fully warmed engine measures just under .5 volts w/key to on.
Ok, I'll have to check that as well. I have noticed that even fully warmed up, the needle on the temp gauge is only 1/4-1/3 up.
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Old Jan 26, 2012 | 08:14 PM
  #182  
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From: tulsa,ok.
Originally Posted by -PM-
Ok, I'll have to check that as well. I have noticed that even fully warmed up, the needle on the temp gauge is only 1/4-1/3 up.
Completely normal. And when was the last time the car ran normally?
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Old Jan 26, 2012 | 08:16 PM
  #183  
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From: Haywards 5000
Originally Posted by -PM-
Ok, I'll have to check that as well. I have noticed that even fully warmed up, the needle on the temp gauge is only 1/4-1/3 up.
That is approximately correct for an s4 stock temp gauge. However, the ECU uses a different water temp sender, located on the back of the water pump housing.
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Old Jan 26, 2012 | 08:28 PM
  #184  
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From: Haywards 5000
Originally Posted by -PM-
Actually after I put the new AFM in, every time I started it, it would idle for 10 seconds and then die.
There is an air bypass adjustment screw that you'll need to adjust. See the second pic on this thread for a diagram:
https://www.rx7club.com/rtek-forum-168/n390-afm-s4-rtek-2-1-a-958559/

This allows some air to bypass the metering door, which is almost closed at idle and zero throttle. The FSM doesn't mention making this adjustment, presumably because the bypass is "correctly set" at the factory. But an aftermarket or reman part may have the bypass partially or completely closed off out of the box.

At throttle > 0, this wouldn't matter much, as the bypass contributes an insignificant fraction, compared to the air flowing through the opened metering door. So, even if you didn't make the bypass adjustment, you would still be able to tell if the AFM made a difference while accelerating.
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Old Jan 26, 2012 | 10:32 PM
  #185  
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From: Twin Cities, MN
Originally Posted by satch
Completely normal. And when was the last time the car ran normally?
The original owner said it ran very well in the beginning of 2011. But it has been sitting since and he hasn't driven a single mile on it.
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Old Jan 26, 2012 | 10:39 PM
  #186  
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From: tulsa,ok.
Originally Posted by -PM-
The original owner said it ran very well in the beginning of 2011. But it has been sitting since and he hasn't driven a single mile on it.
Check pin 2I as suggested and if need be measure the fuel pressure.
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Old Jan 27, 2012 | 01:09 PM
  #187  
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From: Twin Cities, MN
Pin 2I @ ECU (key on, car not running) - Cold: 2.17v

...waiting for it to warm up now.
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Old Jan 27, 2012 | 01:13 PM
  #188  
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From: Twin Cities, MN
I don't think its that sensor though because now I started it up, cold, and the idle fluctuates up and down, up and down...I tried driving it in 1st gear, it started moving, I held the throttle at exactly the same place (1/4 down, in vacuum). It would go then start to die...popped the clutch and blipped the throttle a bit, and it kinda evened out a little. Then 10 more ft, and it bogs again.
This didn't happen before I adjusted the TPS. I have a suspicion that it might be the TPS after all.
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Old Jan 27, 2012 | 01:22 PM
  #189  
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From: tulsa,ok.
Originally Posted by -PM-
I don't think its that sensor though because now I started it up, cold, and the idle fluctuates up and down, up and down...I tried driving it in 1st gear, it started moving, I held the throttle at exactly the same place (1/4 down, in vacuum). It would go then start to die...popped the clutch and blipped the throttle a bit, and it kinda evened out a little. Then 10 more ft, and it bogs again.
This didn't happen before I adjusted the TPS. I have a suspicion that it might be the TPS after all.
Just disconnect the TPS for a bit and see what happens and a fluctuating idle could also be caused by a vacuum leak or maybe the Variable Resistor is misadjusted as it should be set to more rich than lean. If you mess w/the resistor it needs to be done w/the car fully warmed and the Initial Set Coupler jumpered.
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Old Jan 27, 2012 | 01:38 PM
  #190  
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From: Twin Cities, MN
Update:

Pin 2I @ ECU (key on, car not running) - Fully warmed: .47v
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Old Jan 27, 2012 | 01:39 PM
  #191  
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From: Twin Cities, MN
Where is the variable resistor located and what is it responsible for?
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Old Jan 27, 2012 | 01:53 PM
  #192  
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From: Twin Cities, MN
Originally Posted by satch
Just disconnect the TPS for a bit and see what happens and a fluctuating idle could also be caused by a vacuum leak or maybe the Variable Resistor is misadjusted as it should be set to more rich than lean. If you mess w/the resistor it needs to be done w/the car fully warmed and the Initial Set Coupler jumpered.
It fluctuates for a few minutes then levels out and idles at ~800RPMs
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Old Jan 27, 2012 | 01:53 PM
  #193  
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From: tulsa,ok.
Originally Posted by -PM-
Update:

Pin 2I @ ECU (key on, car not running) - Fully warmed: .47v
Next!
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Old Jan 27, 2012 | 01:56 PM
  #194  
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This is turning out to be a hell of a "trial and error" job...lol
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Old Jan 27, 2012 | 01:56 PM
  #195  
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From: tulsa,ok.
Originally Posted by -PM-
Where is the variable resistor located and what is it responsible for?
Helps select how much fuel is used during idle. Located by the passenger strut tower and surrounded by a diamond shaped plate. Has a screw w/a R (rich) and L (lean) printed on the plate. Not likely your problem though but it can affect the idle.
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Old Jan 27, 2012 | 01:57 PM
  #196  
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From: tulsa,ok.
Originally Posted by -PM-
This is turning out to be a hell of a "trial and error" job...lol
Measuring the fuel pressure is probably one of the more vital things you could/should do. And bypassing the fuel relay would have taken but thirty seconds to do when you were busy exchanging the AFM. You would have gotten immediate feedback and could have crossed another possible cause off of the list.
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Old Jan 27, 2012 | 01:58 PM
  #197  
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From: Twin Cities, MN
Originally Posted by satch
Helps select how much fuel is used during idle. Located by the passenger strut tower and surrounded by a diamond shaped plate. Has a screw w/a R (rich) and L (lean) printed on the plate. Not likely your problem though but it can affect the idle.
Ah! That's what that is. I noticed it a few times and could never figure out what its for.
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Old Jan 27, 2012 | 05:55 PM
  #198  
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From: Twin Cities, MN
Originally Posted by satch
Measuring the fuel pressure is probably one of the more vital things you could/should do. And bypassing the fuel relay would have taken but thirty seconds to do when you were busy exchanging the AFM. You would have gotten immediate feedback and could have crossed another possible cause off of the list.
Ok, so all I have to do is disconnect the plug and jump on of the blue wires to one of the blue/red ones?
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Old Jan 27, 2012 | 06:01 PM
  #199  
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From: tulsa,ok.
Originally Posted by -PM-
Ok, so all I have to do is disconnect the plug and jump on of the blue wires to one of the blue/red ones?
Yes.
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Old Jan 30, 2012 | 04:51 PM
  #200  
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Originally Posted by 088
I had a fuel delivery issue in a s5 na car (RTek 2.0) with similar symptoms. Eventually, replaced the fuel pump with a new Nippon/Denso unit, installed a new + wire going directly to the fuel pump, and gave it to Karack to figure out the rest of it (culprit = faulty wire, secondary rear injector ground).

If you're having a fuel pressure problem, it's probably not caused by a bad ECU. Doesn't the Wolf standalone require some setup effort, in which case you'd be complicating the issue? Once you get past the fuel pressure hurdle, you can use logging on the RTek to troubleshoot further.

not much setup fuel wise is done to run the wolf 3d system the ingintion is where you have too work

Originally Posted by sharingan 19
^^^+1
Stop blaming the ecu because your car is in poor condition.

Also, rising rate fprs respond to both boost AND vac, so it is perfectly normal for fuel pressure to drop when you rev an n/a as vac is increased. The only thing faulty is the logic.

Have fun wasting money on a 340lph pump for an n/a.

i was asking it that was normal with the aeromotive frp thats all and my car has a half bridge with 460 cc primarys and 550cc secondary (soon to be 750cc rc's ) so the lean issue up top was really hurting the car alot it felt like i was beating the engine with a stick to get it to rev up.


also when i installed the aeromotive i had the same problem of the pump leaning out at high rpms. as i was driving back to the shop i then noticed a burning smell so i coasted in the shop and started to check it out. the stock connector had almost melted form the new high amp pump so i intalled a relay system that is activated by the stock power signal and draws a power supply straight form the alternator.


THE REASULT OF THIS WIRING LAYOUT WAS AMAZING the car starts instantly and idles perfectly. when driving the car all the 5 years i have had it have i ever FELT the secondary injectors kick "on" with this setup you can and thats when the revs start to climb. the tone of the car is much deeper as well the AFR is almost a constant 13.0 at wot (now i can work of tuning the car)

so i blame the stock connector because even tho i replaced the pump with a better one i still got the same problem untill i bypassed the stock connector......
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