tayman
NAXJA Forum User
- Location
- Niceville, FL
it's an AX-15 and I don't have A/C... would it be so bad to just leave it this way? in the closed position? I don't have any engine accessories to kick on and change idle speed.
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Renix Not starting. Fuel pump not priming. only 7v at pump.
- Thread starter tayman
- Start date
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
You're sure the butterfly is as closed as it's supposed to be?
Cruiser’s Renix Throttle Body Butterfly Adjustment
Okay. Let's start from scratch. First off, that's not an idle adjustment screw. It's a throttle butterfly stop screw. It's purpose is to allow the butterfly to be as close to completely closed as it can be without binding or wearing into the throttle body. It was never intended to be adjusted in the field. But, Uncle bob didn’t know that, did he?
Engine off. Back off the butterfly stop screw with a 3/32" allen wrench until the butterfly is completely closed. Now. turn the screw in until the FAINTEST movement of the butterfly opening is detected. This can be done more easily with the throttle body removed. If you remove the throttle body, be sure to replace the gasket underneath it after thoroughly cleaning the old one off.
Revised 07/07/2012
Cruiser’s Renix Throttle Body Butterfly Adjustment
Okay. Let's start from scratch. First off, that's not an idle adjustment screw. It's a throttle butterfly stop screw. It's purpose is to allow the butterfly to be as close to completely closed as it can be without binding or wearing into the throttle body. It was never intended to be adjusted in the field. But, Uncle bob didn’t know that, did he?
Engine off. Back off the butterfly stop screw with a 3/32" allen wrench until the butterfly is completely closed. Now. turn the screw in until the FAINTEST movement of the butterfly opening is detected. This can be done more easily with the throttle body removed. If you remove the throttle body, be sure to replace the gasket underneath it after thoroughly cleaning the old one off.
Revised 07/07/2012
tayman
NAXJA Forum User
- Location
- Niceville, FL
ok, you must think I don't actually know what I'm saying...
I didn't adjust the idle screw. I shifted the position of the butterfly on the shaft by loosening the two screws on the shaft and physically moving the butterfly until it was fully sealed.
I didn't adjust the idle screw. I shifted the position of the butterfly on the shaft by loosening the two screws on the shaft and physically moving the butterfly until it was fully sealed.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
Ooooh. Makes me wonder why it wasn't seated in the first place. Has someone messed with that stop screw before?
tayman
NAXJA Forum User
- Location
- Niceville, FL
I grew up with a grandpa who built race cars and engines... I get the mechanical things. It's the electrical stuff that confuses the HELL out of me
tayman
NAXJA Forum User
- Location
- Niceville, FL
I've played with it a little bit. Never actually ended up leaving it changed. the butterfly was "just a thought" it didn't affect anything. I think the only reason covering it had any effect was because I was covering the bypass hole too.
cruiser54
NAXJA Forum User
- Location
- Prescott, Az
If it were me, at this point I would loosen the butterfly screws, back off the stop screw, tighten the butterfly screws, then set the stop screw per my instructions.
tayman
NAXJA Forum User
- Location
- Niceville, FL
it's closed all the way. I'm sure.
tayman
NAXJA Forum User
- Location
- Niceville, FL
the fact that I was able to get the IAC to close, and that brought the idle down to ABSOLUTELY PERFECT tells me that the butterfly is not an issue...
It idles better now than it ever has.
Now I'm just looking for how to test the IAC, or if I even need to bother.
It idles better now than it ever has.
Now I'm just looking for how to test the IAC, or if I even need to bother.
- Location
- MilkyWay Galaxy
Don't both.
Something it seems is telling the IAC to open too much in error. In my case it was the MAT that was bad and the ECU was using bad MAT data to over open the IAC. Have you completed the hot/cold water tests of the MAT, ohms readings after cleaning it? If it is to dirty it will not respond to air temp changes fast enough.
Take that info I sent you, read it, study it, and then retest the sensors live, while running, especially when the high idle kicks in, as that will be when the bad data shows up and finally lets you isolate the gremlin. Also, you still may have bad sensor ground splice(s) in the harness, that are changing ground resistance when the harness moves, or thermal changes affect the loose splice-ground in the harness. Pay special attention to the MAP and MAT grounds, and TPS sensor ground on the ECU side of the TPS. The TPS has two separate grounds!!!
Also, does the IAC have a good o'ring? I am assuming it does, but?
Something it seems is telling the IAC to open too much in error. In my case it was the MAT that was bad and the ECU was using bad MAT data to over open the IAC. Have you completed the hot/cold water tests of the MAT, ohms readings after cleaning it? If it is to dirty it will not respond to air temp changes fast enough.
Take that info I sent you, read it, study it, and then retest the sensors live, while running, especially when the high idle kicks in, as that will be when the bad data shows up and finally lets you isolate the gremlin. Also, you still may have bad sensor ground splice(s) in the harness, that are changing ground resistance when the harness moves, or thermal changes affect the loose splice-ground in the harness. Pay special attention to the MAP and MAT grounds, and TPS sensor ground on the ECU side of the TPS. The TPS has two separate grounds!!!
Also, does the IAC have a good o'ring? I am assuming it does, but?
tayman
NAXJA Forum User
- Location
- Niceville, FL
Well, I have an ax-15 so I only have one tps ground.
Not really tracking the thermal changes in grounds... it only takes (usually) 5 or 6 seconds to idle down... though recently it's decided not to come down at all unless the IAC is closed.
I'll do the MAT hot/cold water test.
I assume the IAC O ring is good, because when I cover the IAC port on the intake, it idles PERFECTLY immediately.
Not really tracking the thermal changes in grounds... it only takes (usually) 5 or 6 seconds to idle down... though recently it's decided not to come down at all unless the IAC is closed.
I'll do the MAT hot/cold water test.
I assume the IAC O ring is good, because when I cover the IAC port on the intake, it idles PERFECTLY immediately.
- Location
- MilkyWay Galaxy
I would be curious to know if the high idle problem stops if the O2 sensor is disconnected before you start it!!!
Does it idle normal at start up then go high, or does it go directly to high idle immediately (with every re-connected)?
Does it idle normal at start up then go high, or does it go directly to high idle immediately (with every re-connected)?
tayman
NAXJA Forum User
- Location
- Niceville, FL
I'll try that.
it goes straight to 3k. It used to come down after a few seconds, but recently would just stay up there.
it goes straight to 3k. It used to come down after a few seconds, but recently would just stay up there.
old_man
NAXJA Forum User
- Location
- Loveland, Colorado
I haven't read all the way through this thread but a high idle at initial start that soon falls tends to be related to the fact that the ECU is supposed to set the IAC just after you turn off the ignition switch so at start the idle is close. In order to keep the power to the ECU, thus enabling this, there is what is called the Latch Relay. If it fails, the ECU leaves the IAC retracted and you get a high idle until the ECU detects it and adjusts it.
tayman
NAXJA Forum User
- Location
- Niceville, FL
maybe I should also replace the relay then? I don't "think" it's bad, but it IS old...
why would it affect it for like 5 to 6 seconds though? And more recently, the IAC happarently hasn't been operating at all. I had to cover the port and uncover it then re-cover, uncover an d what not in order to "trick" it into closing.
why would it affect it for like 5 to 6 seconds though? And more recently, the IAC happarently hasn't been operating at all. I had to cover the port and uncover it then re-cover, uncover an d what not in order to "trick" it into closing.
- Location
- MilkyWay Galaxy
Old man is right, which is why I asked my last question, but your point, or last question is also correct. You may have both problems!!! B+ latch relay problem could also be dirty contacts in the female wiring harness side as well as the relay that goes in the connector. But it would not be the problem causing a continuous high idle.
But I am still leaning towards your current problem being bad sensor data at the ECU. The question is what sensor data is bad. Only way I know to figure it it out is to back probe all the sensor data with a volt meter while the idle is high to find the bad data source. It could be bad wires from a sensor to the ECU so at some boint you need see what data is getting to the ECU as last resort. But I would start at the wiring harness on the ECU side of the connectors for data watching first.
But I am still leaning towards your current problem being bad sensor data at the ECU. The question is what sensor data is bad. Only way I know to figure it it out is to back probe all the sensor data with a volt meter while the idle is high to find the bad data source. It could be bad wires from a sensor to the ECU so at some boint you need see what data is getting to the ECU as last resort. But I would start at the wiring harness on the ECU side of the connectors for data watching first.
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tayman
NAXJA Forum User
- Location
- Niceville, FL
ok, here's what I'm thinking. I'll try it with the O2 disconnected. if that doesnnt seem to work, I'll replace the B latch. I try to do both today
- Location
- MilkyWay Galaxy
Good. The O2 sensor test will tell us if the ECU is acting badly based on feed back loop data from the O2 sensor. The ECU will default to open loop tables in the ECU using just the TPS, CTS, MAT and MAP sensors.
Then try disconnect the CTS, then the MAT (while running, if the O2 sensor delete has no effect). It won't run with out the MAP sensor.
Then try disconnect the CTS, then the MAT (while running, if the O2 sensor delete has no effect). It won't run with out the MAP sensor.
tayman
NAXJA Forum User
- Location
- Niceville, FL
Got it. So this is basically a test to see if it's a bad O2?
- Location
- MilkyWay Galaxy
No, that would be jumping to conclusions. It could be an exhaust leak, or other engine-fuel anomalies confusing the O2 sensor and thus the ECU, or even a wiring harness damage issue in the O2 sensor wires. Further testing would be needed next.
You can also test the wiring harness side of the O2 sensor with it disconnected, for 2 good grounds (black IIRC), 12 volts at the fat orange wire and 5 volts at the fourth wire.
