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Discussion Starter #1
Hi Everyone, newbie to this forum with a question reg my jeep.
I am having big problems with the erratic running of my jeep and sometimes not starting at all.
Garage told me that the Air mass sensor was the problem, So I bought a new one (not cheap) only to find the same problem exists but when the sensor is unplugged the car seems to be OK
My question is this:
Can I run my jeep without the sensor being plugged in, and what harm can it do if any?
Any thoughts would be much appreciated.
Nick
 

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Just as a general response, when you unplug the MAF, the ECU no longer uses the MAF signal, but runs on predetermined values, which is why your car will run differently (much richer and use more gas, etc.) with the MAF unplugged. Normally, if the MAF is bad, your ECU will throw a code, actually, and the check engine light will be on with the car running. So, first question is, is the CEL on with the key on and off when running?
Normally, it is a good idea to have a compression test done on the engine to see if the car is timed properly, as well as confirm your ignition timing, before you start throwing parts (and expensive ones) at the car. I would do a compression test first, before diagnosing anything else.
The MAF is fairly easy to test. The blue/black wire at the MAF connector must have 12v to it (key on, and backprobe the connector), the black wire at that same connector must have less than 0.5v, the gray/black wire must have 1.0-1.6v with the key on, engine not running. Then while still backprobing the gray/black wire, start the engine - the voltage should now increase to about 2.0v, and if you rev the engine, the voltage should rise with the rpm of the engine.
Hopefully, your mechanic checked the wiring to the MAF (probably not, actually, considering your post), which, if bad, would cause the same problem with a new MAF.
 

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As Max has pointed out, a lack of information on what you're driving limits the help we can offer - the Escudo name has been used on five or six different models sold from 89 onwards.

Generally speaking though - disconnecting the MAF sensor will force an error that puts the ECU in a "limp home" mode - it is unable to measure how much air is going into the engine and will be unable to fuel correctly. Rather than leave you stranded, it will err on the rich side & over fuel, which apart from the increased fuel consumption has other implications on engine life.

Definitely NOT recommended.

Next - depending on which Escudo you have, and which MAF it uses - there are a number of "non-genuine" replacements with the same part number that have reportedly not worked, so that is one possible cause of your problem, and, if I were to assume the "garage" determined the MAF as defective based on a check engine code - the codes that point to MAF (or any other sensor) don't mean the sensor is defective, the codes tell you that the ECU doesn't "trust" the data it's receiving as valid - you have to determine why that data is not valid - bad wiring & poor connections are a possibility.
 

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Here's what he posted in the new member area:

Hi there everyone, I am a new member from Cyprus owning a Suzuki Escudo 1994 16v petrol 4wd.

That info might help to better diagnose the issue.
 

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Discussion Starter #6
Hi All, Thanks for the helpful comments so far, We have now found out that the problem is not the air mass sensor but a faulty throttle valve and choke!. We cannot source these parts here, does anyone know if the parts are available from another model?
Many Thanks.
 

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It will be the same as a 16V Vitara of the same age. What is wrong with the existing throttle valve? could it just be that it needs cleaning out?
 

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Presuming that you have a computer, a MAF, etc., then I believe that it's safe to say that you do NOT have a choke. Perhaps you should give some more information about how the car is running, for better direction with your problem, It would appear to me that it is possible that the mechanic you are using is not really familiar with these cars.
 

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Technically the butterfly is a choke.
 

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Hmmm....and the butterfly is a throttle valve. :)
But assuming that a choke is something that is only used at cold start to enrich the fuel/air mixture, then if you are EFI, you wouldn't have one - unless, of course, if you are talking about the mechanical air valve. Ah, but that's not a butterfly.....
 

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