Rtek Update with my 2800rpm buck
Senior Member
Joined: Mar 2004
Posts: 458
Likes: 0
From: Cleveland
If I'm not mistaken, the ATP sensor is inside the car on the passenger side kick panel. (Tucked in pretty deep) It does look like a boost sensor.
I told you th read the manual when you asked if the box should be checked.
I made an incorrect statement in my previous post. It should have read:
You would check the box if you wanted to use the ATP input to log an external sensor like a wideband.
or
You would not check the box if you still had the factory ATP sensor installed.
But again, this is in the manual (Steps 13 and 14 of the Quickstart: Initial setup procedure, the first page after the table of contents.). I'm sorry you dont want to be told to read the manual but it's a bit frustrated to be expected to help you troubleshoot your problem when you wont even take the time to set up the Rtek properly.
I made an incorrect statement in my previous post. It should have read:
You would check the box if you wanted to use the ATP input to log an external sensor like a wideband.
or
You would not check the box if you still had the factory ATP sensor installed.
But again, this is in the manual (Steps 13 and 14 of the Quickstart: Initial setup procedure, the first page after the table of contents.). I'm sorry you dont want to be told to read the manual but it's a bit frustrated to be expected to help you troubleshoot your problem when you wont even take the time to set up the Rtek properly.
Last edited by turbo2ltr; Jul 14, 2007 at 08:37 AM.
The current is drawn from the injectors as you gain load. That is how it is supposed to work.
Now, on a new note. I found one of my secondary injectors was grounding out a bit on the ecu wire (3h), Green with red stripe wire. I found this out by disconnecting the main grounds under the UIM, connecting one side of the volt meter (on OHM test) to the ground wires and the other to the 4 inj wires going into the ecu ( the ecu plugs where disconencted as well). Three of the ECU wires showed no signs of grounding , but one did . So, I had to rip apart the main harness and re-run some wires. I did all my inj wires over. Now I see no sign of a crosswire. Not sure if this is my problem being I have not started the car, but feels right this time. I would check all grounds over.
Now, on a new note. I found one of my secondary injectors was grounding out a bit on the ecu wire (3h), Green with red stripe wire. I found this out by disconnecting the main grounds under the UIM, connecting one side of the volt meter (on OHM test) to the ground wires and the other to the 4 inj wires going into the ecu ( the ecu plugs where disconencted as well). Three of the ECU wires showed no signs of grounding , but one did . So, I had to rip apart the main harness and re-run some wires. I did all my inj wires over. Now I see no sign of a crosswire. Not sure if this is my problem being I have not started the car, but feels right this time. I would check all grounds over.
If I had a battery and a motor to complete a circuit and had a meter across the circuit the voltage should be the same.
Yeah...but are the injectors that much of a load bearing device to drop voltage to 12 volts? Plus, doesn't your alternator makes sure that your battery see like 13-14 volts.
If I had a battery and a motor to complete a circuit and had a meter across the circuit the voltage should be the same.
If I had a battery and a motor to complete a circuit and had a meter across the circuit the voltage should be the same.
You are missing the point that he wasn't measuring battery voltage, he was measuring the switched output of the ECU.
The injectors are wired like:
Code:
+12v ---- Inj ----- ECU ----- ground
^ ^ ^
A B C
If you measured at A, you would get 12V all the time. This is where you may see a drop as the injectors are fired more (higher RPM) and for longer ( more load).
If you measured at B, which is at the connector of the ECU, there are two states you can see...
When the injector is off, you would measure the 12V through the injector. There would be no voltage drop across the injector because the ECU has the B wire floating and ohms law says if there is no current flowing, then there is no voltage drop. So you can "see" the 12V from the other side of the injector.
When the injector is on, The ECU connects the B wire to ground, current will be flowing through the injector, causing almost the full 12V to be "used" in the injector, so you will see almost zero volts. Any resistance in 1: the ground wire to the ECU and 2: the electronic driver thats used to switch the ground on and off, will cause the reading at B to read slightly above 0v. Whatever voltage is measured at this point will be "used" on the way to the ground on the battery.
Now, the "problem" is these states switch back and forth very quickly. The typical multimeter will simply average the states. So if you happened to have 50% injector duty cycle at the time of measurement, the voltage reading on the B wire would be ~6V. The more load you have, the more the injectors are "on". The more the injectors are on, the more the B wire is grounded. The more it's grounded, the lower the average voltage will be on the B wire.
To measure voltage on the B wire properly, you need an Oscilloscope.
You are missing the point that he wasn't measuring battery voltage, he was measuring the switched output of the ECU.
The injectors are wired like:
The ECU controls the injector by completing the circuit. When it wants to turn it on, it grounds the injector wire (B) thus completing the circuit through C to ground. When it wants to turn it off, it "floats" the B wire, breaking the circuit. i.e. it connects it to nothing.
If you measured at A, you would get 12V all the time. This is where you may see a drop as the injectors are fired more (higher RPM) and for longer ( more load).
If you measured at B, which is at the connector of the ECU, there are two states you can see...
When the injector is off, you would measure the 12V through the injector. There would be no voltage drop across the injector because the ECU has the B wire floating and ohms law says if there is no current flowing, then there is no voltage drop. So you can "see" the 12V from the other side of the injector.
When the injector is on, The ECU connects the B wire to ground, current will be flowing through the injector, causing almost the full 12V to be "used" in the injector, so you will see almost zero volts. Any resistance in 1: the ground wire to the ECU and 2: the electronic driver thats used to switch the ground on and off, will cause the reading at B to read slightly above 0v. Whatever voltage is measured at this point will be "used" on the way to the ground on the battery.
Now, the "problem" is these states switch back and forth very quickly. The typical multimeter will simply average the states. So if you happened to have 50% injector duty cycle at the time of measurement, the voltage reading on the B wire would be ~6V. The more load you have, the more the injectors are "on". The more the injectors are on, the more the B wire is grounded. The more it's grounded, the lower the average voltage will be on the B wire.
To measure voltage on the B wire properly, you need an Oscilloscope.
The injectors are wired like:
Code:
+12v ---- Inj ----- ECU ----- ground
^ ^ ^
A B C
If you measured at A, you would get 12V all the time. This is where you may see a drop as the injectors are fired more (higher RPM) and for longer ( more load).
If you measured at B, which is at the connector of the ECU, there are two states you can see...
When the injector is off, you would measure the 12V through the injector. There would be no voltage drop across the injector because the ECU has the B wire floating and ohms law says if there is no current flowing, then there is no voltage drop. So you can "see" the 12V from the other side of the injector.
When the injector is on, The ECU connects the B wire to ground, current will be flowing through the injector, causing almost the full 12V to be "used" in the injector, so you will see almost zero volts. Any resistance in 1: the ground wire to the ECU and 2: the electronic driver thats used to switch the ground on and off, will cause the reading at B to read slightly above 0v. Whatever voltage is measured at this point will be "used" on the way to the ground on the battery.
Now, the "problem" is these states switch back and forth very quickly. The typical multimeter will simply average the states. So if you happened to have 50% injector duty cycle at the time of measurement, the voltage reading on the B wire would be ~6V. The more load you have, the more the injectors are "on". The more the injectors are on, the more the B wire is grounded. The more it's grounded, the lower the average voltage will be on the B wire.
To measure voltage on the B wire properly, you need an Oscilloscope.
RotoriousRx7
Joined: Oct 2005
Posts: 1,236
Likes: 0
From: goodlettsville,tennessee 37072
well i think my atp box is checked and its not supposed to be ?so im going to check that out, also i drove my car around awhile last night andthe air was cool.. it seemed like the more i drove the worse it got?
RotoriousRx7
Joined: Oct 2005
Posts: 1,236
Likes: 0
From: goodlettsville,tennessee 37072
so i didnt understand that if the box was unchecked it would use the factory atp sensor... i figured you had to set the elavation anyway.. i apologize for this waste of time.. but we will see if that fixes MY issue though.
Can someone get to their ECU and do a OHM test from the main engine ground to the injector wires? 3E,3C,3H,3F. I am still getting some grounding on these wires. I do not imagine that is right. OHM test on 2K is reading .245
I just got done reading this..maybe it helps or maybe not.
Most of us have known for quite a while what is causing the bucking and hesitation around 3000rpm in the thrid gens. It's no great mystery. The problem that everyone is having is trying to correct it. If you scan through the shop manual you will see that only one thing really happens at this point, the secondary injectors come on. It's not strictly based on RPM, but instead load condition, which is why it doesn't always happen at the same RPM. Everyone should have figured out by now that you can drive around the problem by lowering the load, ie: go to a lower gear. The bucking is happening when the car is on the break point of the load map. They keep turning on and off, which is why if you are hard on the throttle you don't notice any bucking because it is a smooth transition through that cycle and there is no on off on off...
The solution that was tried with the PFS computer was to make it super rich throughout that RPM range. The problem with this is as I mentioned it is a load point not an RPM point. It is like using a shotgun with buckshot to kill a fly buzzing around. Additionally you are not controlling whether or not the injector turns on, only increasing the total percentage of fuel from whatever happens to be on. If you have datalogging you will see it happen. The RPM etc are going up and the pulsewidth as well and then suddenly the pulsewidth nearly cuts in half. This is the secondary injectors coming on. Anyway if somebody were trying to solve this they would have to come up with a way to keep the ECU from returning to the loadpoint just before the injectors turn on. Which is probably not very feasable and would cause a number of collateral problems. The other option would be to extend the full pulsewidth of the primary injectors, or create more of an overlap of the two. The most effective way around the whole problem though is to modify your driving style. Don't drive in that load range, use a different gear etc.
The O2 sensor things as far as I can see is a simple way to richen everything up due to the error with no feedback. It probably defaults to a overly rich safe mode.
The solution that was tried with the PFS computer was to make it super rich throughout that RPM range. The problem with this is as I mentioned it is a load point not an RPM point. It is like using a shotgun with buckshot to kill a fly buzzing around. Additionally you are not controlling whether or not the injector turns on, only increasing the total percentage of fuel from whatever happens to be on. If you have datalogging you will see it happen. The RPM etc are going up and the pulsewidth as well and then suddenly the pulsewidth nearly cuts in half. This is the secondary injectors coming on. Anyway if somebody were trying to solve this they would have to come up with a way to keep the ECU from returning to the loadpoint just before the injectors turn on. Which is probably not very feasable and would cause a number of collateral problems. The other option would be to extend the full pulsewidth of the primary injectors, or create more of an overlap of the two. The most effective way around the whole problem though is to modify your driving style. Don't drive in that load range, use a different gear etc.
The O2 sensor things as far as I can see is a simple way to richen everything up due to the error with no feedback. It probably defaults to a overly rich safe mode.
Originally Posted by rogrx7
I just got done reading this..maybe it helps or maybe not.
and i disagree with that writeup.. the staging problems are related to load, but only because there are shorter p/w at lower loads, which make injector turn-on time delays more evident.
The bucking is happening when the car is on the break point of the load map. They keep turning on and off, which is why if you are hard on the throttle you don't notice any bucking because it is a smooth transition through that cycle and there is no on off on off...
as far as staging hesitations go, i believe this is an accurate description of the problem:
https://www.rx7club.com/single-turbo-rx-7s-23/goodby-resistors-hello-peak-hold-666741/
Interesting. Where did you read this?
This is exactly where we are concentrating our efforts.
> The other option would be to extend the full pulsewidth of the primary injectors,
We already do this. We increased the primary max DC by 5%.
This is exactly where we are concentrating our efforts.
> The other option would be to extend the full pulsewidth of the primary injectors,
We already do this. We increased the primary max DC by 5%.
http://www.fd3s.net/3k_hesitation.html
its for the third gen...but had some interesting stuff
its for the third gen...but had some interesting stuff
" The response delay of the pressure sensor followed mounted
by rapid acceleration temporarily causes a lean fuel mixture.
The double throttle control system prevents hesitation caused
by this lean fuel mixture by slightly delaying the opening of
the double throttle valve after the secondary throttle valve.
The double throttle valve is controlled by the ECU through the
solenoid valve."
by rapid acceleration temporarily causes a lean fuel mixture.
The double throttle control system prevents hesitation caused
by this lean fuel mixture by slightly delaying the opening of
the double throttle valve after the secondary throttle valve.
The double throttle valve is controlled by the ECU through the
solenoid valve."
this has to do with 3800 STAGING hesitation problems, when the secondaries are turning on... the problems in this thread have to do with hesitations while cruising in vacuum with secondaries off = completely different.. secondaries wont even start to come on until you are above 0 psi boost
and i disagree with that writeup.. the staging problems are related to load, but only because there are shorter p/w at lower loads, which make injector turn-on time delays more evident.
this is not a cause of staging hesitations either.. what do you think is happening to your injectors all the time, regardless of whether secondaries are on or off??
as far as staging hesitations go, i believe this is an accurate description of the problem:
https://www.rx7club.com/showthread.php?t=666741
and i disagree with that writeup.. the staging problems are related to load, but only because there are shorter p/w at lower loads, which make injector turn-on time delays more evident.
this is not a cause of staging hesitations either.. what do you think is happening to your injectors all the time, regardless of whether secondaries are on or off??
as far as staging hesitations go, i believe this is an accurate description of the problem:
https://www.rx7club.com/showthread.php?t=666741
I don't think thats the problem.
please explain why not?
the quote above does not attempt to explain what the problem, it only offers possible "bandaids" A: make it overly rich in the staging areas, B: altering the staging return criteria, and C: Injector staging overlap
imo the underlying problem is using a peak/hold style injector with a saturation style driver
what would be really cool, is if the rtek guys replaced the injector drivers with higher-current driver hardware (not entirely sure what this consists of), and added an option in the ecu for low or high imp injectors to do the two types of injector driving
or actually, a betters solution would be to set the staging criteria to injector p/w.. if the p/w is above a certain limit, then the staging would be enabled, regardless of boost/rpm/load, etc this would eliminate staging at lower loads, causing hesitations. but again, not sure about the feasibility of that in the ecu
the quote above does not attempt to explain what the problem, it only offers possible "bandaids" A: make it overly rich in the staging areas, B: altering the staging return criteria, and C: Injector staging overlap
imo the underlying problem is using a peak/hold style injector with a saturation style driver
what would be really cool, is if the rtek guys replaced the injector drivers with higher-current driver hardware (not entirely sure what this consists of), and added an option in the ecu for low or high imp injectors to do the two types of injector driving
or actually, a betters solution would be to set the staging criteria to injector p/w.. if the p/w is above a certain limit, then the staging would be enabled, regardless of boost/rpm/load, etc this would eliminate staging at lower loads, causing hesitations. but again, not sure about the feasibility of that in the ecu
Senior Member
Joined: Apr 2007
Posts: 268
Likes: 0
From: San Diego, Ca
what would be really cool, is if the rtek guys replaced the injector drivers with higher-current driver hardware (not entirely sure what this consists of), and added an option in the ecu for low or high imp injectors to do the two types of injector driving
Well, figure that low imp ecus with a 7 ohm resistor in series create a circuit that's measures roughly ~9 ohms. Figure a charging system that puts out 14 volts, so about 1.5 amps drawn from each injector circuit. Say we take our 2 ohm injector and drive it directly from the same circuit, now we're talking 7 amps per channel. The ecu itself is not designed to draw that much current across the entire driver circuit. This is why a vast majority of cars that come stock with low imp injectors have resistor boxes, because the ECU itself is not capable of driving multiple high current circuits. Ignition systems use ignitors for the same reason.
im debating getting an injector driver kit just to see if it makes a difference
Senior Member
Joined: Apr 2007
Posts: 268
Likes: 0
From: San Diego, Ca
agreed 100%. i meant actually opening up the ecu and replacing the drivers with ones that can handle the higher current needed and can deliver a peak and hold signal.. but that may be a little too involved, b/c im not sure that would entail a simple transistor swap
im debating getting an injector driver kit just to see if it makes a difference
im debating getting an injector driver kit just to see if it makes a difference
I'm sure an injector driver would make a noticeable difference, however, I don't believe that it is absolutely neccessary to make the rtek work properly. The gains in lower pulsewidth noted in the thread you linked is impressive though.