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ZUKIWORLD Discussion Forum => Suzuki 4x4 Forum => Topic started by: RJkick on December 22, 2009, 09:31:08 AM
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I have a '92 4dr Sidekick 1.6 16v that is causing me headaches.
The zuk will run fine and then all of a sudden if you press the gas pedal to the floor it goes to about 3000 RPM and that's it, if you barely press the gas pedal it still runs and you can change gears, but when you come to a stop it will idle at 2000 rpm and then drop to a stall and you have to restart the motor. If I continue driving it gets progressively worse. If I let it sit for an hour or two or overnight it will run fine for a while and then the issue returns. I had a CEL but after replacing the computer it no longer is on.
So far I have changed the Computer, made sure all my grounds were proper, and fixed the wiring that I thought was causing me the problem under the dash, whenever I moved them I could get the zuk to idle porly so I thought that was it.
Please give me any directions or suggestions you think might cause this issue
Thanks
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Sound like rust in the fuel tank is clogging up the filter mesh before the fuel pump. The symptom is that it run fine when first started and progressively get worse but when you switch off and start again, it seem back to normal for a while before it start acting up again.
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Check your tps sensor. These kicks are famous for those things giving up the ghost. Mine had the same problem awhile back after replacing fuel filter and fuel pump and still having same issues i checked the tps and it was bad replaced it and it's good as new.
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The big issue is the intermittent times it happens. It is running fine now so the voltages check out. Now I have to carry the volt meter and try to make it happen and then check the voltage
Sounds like that is it and I found one for $70 so I may just change it out
I really hope it isn't the MAF sensor that is more in the $300 range
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Does the idle still change when you wiggle the wires under the dash?
Another thing is your ignition module may be going bad in the distributor. The advance and retard or timing can cause the idle to change also.
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if you think its the maf just unplug it and see if it changes the way it runs. just make sure that you clear the code when your done. hell i dont even have the maf or a cat on mine runs great. I'm sure the mpg's suck but its off road only so i dont care.
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Well, I have been driving around for a few days now and am having trouble recreating the issue. I haven't gotten a check engine light since the last clear so there's nothing there.
Thanks for the heads up on the MAF
More to follow
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Finally - Turns out the ECU\Computer is not putting out the correct voltage when the issue occurs so that must be the issue. I hope
Thanks
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I just read on another site a couple of days ago that these ECU's have what they call a back up mode, not a limp home mode, that does some crazy chit. One of the things the guy mentioned was only being able to get 3000 RPM out of it. Maybe your ECU is starting to take a crap? Not sure if I should post a link to the other site here or not so, if you PM me I can send it to you that way maybe. -Ed
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I just read on another site a couple of days ago that these ECU's have what they call a back up mode, not a limp home mode, that does some crazy chit. One of the things the guy mentioned was only being able to get 3000 RPM out of it. Maybe your ECU is starting to take a crap? Not sure if I should post a link to the other site here or not so, if you PM me I can send it to you that way maybe. -Ed
There are lots of different limp home modes, depending on what sensor is affected. If the processor fails then there is back up logic that should kick in, this is a very crude system and runs rich with retarded timing. It will usually rev to around 3000rpm before you get a rich mixture misfire.
If you're not getting the correct output voltage (which output voltage?) then you most likely have a capacitor failure.
The limp home mode for no MAF is to estimate MAF using a TPS v RPM look up table.
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That's what I was thinking, except I thought it was a voltage regulator chip
in the ECU, reference voltage is typically about 5V but this could vary from
ECU to ECU. The voltage is measured by the computer is in hundredths of
volts, so this circuit has to be very exact in supplied voltage, a fluctuation
of .01 volts means different injection settings to the computer
Wild
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it is a 5V that is not sending 5V to the TPS and MAF sensors. The ecu is being repaired as we write so hopefully I get it back this week.
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That's what I was thinking, except I thought it was a voltage regulator chip
in the ECU, reference voltage is typically about 5V but this could vary from
ECU to ECU. The voltage is measured by the computer is in hundredths of
volts, so this circuit has to be very exact in supplied voltage, a fluctuation
of .01 volts means different injection settings to the computer
Wild
I missed this post originally. The voltage regulator isn't all that accurate, the analogue to digital converter is ratiometric so any errors cancel out.