Suzuki DF60 2004 Won't go above 3000 rpms No error codes

[redlowrey]

Very good I was thinking that you had the sensor unplugged, because the computer will send a bias voltage down that wire around 1.5 volts with the sensor unplugged key on.

[go2ski]

The map sensor is connected to the engine the only thing that’s not connected is the hose to the map sensor.

[redlowrey]

You are checking these voltages with the map sensor wiring plug connected aren’t you, it just dawned on me, because I see changes on your sds, you say no changes at all.

[redlowrey]

Ok it looks like the sensor has failed just do one more test, connect your multimeter ground to the battery negative and probe the black and white wire, sensor ground with the key on, you should not see more than 40 mv on it.

I have equipment to test the sensor on the engine or on the work bench and it’s hard over the internet trying to show someone how something works and how to test and be confident that the tests are right.

When I test a map sensor on the engine I will check supply voltage 5 volts, sensor ground, no more than 40 mv, signal voltage using a vacuum pump which will vary between 4 volts no vacuum, to 1 volt high gauge vacuum, and I will tap on the sensor to see if there is any changes to the readings.

[go2ski]

The voltage is all 1.7-1.8 on key on engine off and ldle and full throttle on the white wire I did test that.

[redlowrey]

mate listen carefully only do what I ask you to do, with your meter connected to the white signal wire with the key on engine off what have you got.
At sea level it should be 4 volts what is it.

With the hose disconnected as soon as it starts and the computer does not see a changing voltage it will bring on the check engine light and substitute a value for it.
This is why I said to you if you see 4 volts on the signal wire with the key on engine off as soon as the engine starts go to wide open throttle.
Just tell me what voltage you have with the key on engine off and we will go from there.

[go2ski]

Could you also tell me what the volts on the white wire are supposed to be.

[go2ski]

[go2ski]

The white wire reads 1.7-1.8 volts with the hose disconnected I tested that again in gear in idle and off it reads the same. I took a recording with my phone of the sds due to my software having problems and I uploaded it here. I want to be sure the MAP sensor is failing because it isn't cheap.

(If the link isn't working go to the other videos from the previous replies it will be on the same channel most recent upload)

[redlowrey]

With the hose disconnected the voltage should have been around 4 volts and stay at that voltage because there is no vacuum on it to change it, map sensor voltage will vary between 4 volts when the engine is not running no vacuum, to around 1 volt when the engine is idling high gauge vacuum , then vary as the throttle is opening and closing with different loads, to have 1to 2 volts on the white signal wire when the hose is off indicates the sensor has failed.

If you can leave the hose off connect your meter to the signal wire and test the sensor with the key on to see if you can get it to show 4 volts, even if you tap the sensor with something, if you start the engine and go to full throttle, it should rev straight up tp the limiter.

[go2ski]

When I tested the red wire with the multimeter it gave 4-5v the white wire gave 1-2v with the hose off my software didn’t record the sds for some reason ill do it again but it gave me two errors when I removed the hose one for the hose being removed and one for the air screw

[redlowrey]

I should have added connect your sds up when you do this

[redlowrey]

I had a look at the sds out of the water and at 22 seconds it was injecting 7ms and 20mcc of fuel plenty, at 23 seconds it went back to 2.2 ms and 5mcc of fuel with the throttle nearly all the way and over 3.500 rpm. and 8.7 in hg of vacuum something is amiss here. I have never seen a map sensor fail like this the signal voltage will be going 4 volts 1 volt 4 volts 1 volt and so on.

Don't worry about the other tests at the moment, do this one first, remove the map sensor hose from the engine and leave it unplugged, that will leave the map signal voltage at around 4 volts start the engine and as soon as it starts go to wide open throttle. Dou you know how to use a multimeter. Do this out of the water.

[go2ski]

Also when I do these tests should I do them in the water since that’s when my rpms won’t go above 3000 rpms

[go2ski]

redlowrey the engine will go over 3000 rpms out of water sometimes. The other day it wouldn’t go above 3000rpms out of water now it will but when it goes in the water back to less than 3000 rpms.