# weird cis-e issue (bad dpr?)



## johnnyGO (Feb 23, 2009)

The car starts sometimes and other times it doesint, when it is running the idle surges badly. Ive got a a/f gauge so I can see the ecu working so its not that, when running the a/f gauge with the o2 unplugged from the ecu it shows its running pretty lean but when I go to richen it up the idle gets worse.
Im getting good, spark and fuel, the meter plate is fine and free. The car ran PERFECT before this issue so this is why Im thinking it might be the dpr.


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## jhax (Aug 1, 2008)

when i got my car it had similar problems, also when i romped on the pedal it cut out and studdered. i did also have the surging idle but that was only after i changed the DPR who knows though, grab one from a yard and replace it


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## beastyben1 (Mar 12, 2009)

i had some wicked rpm surge, my mech replaced the dpr and and smoothed out nicely.
even more smooth when using a fuel enrichment module.


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## wclark (Mar 28, 2001)

*Re: weird cis-e issue (johnnyGO)*


_Quote, originally posted by *johnnyGO* »_The car starts sometimes and other times it doesint, when it is running the idle surges badly. Ive got a a/f gauge so I can see the ecu working so its not that, when running the a/f gauge with the o2 unplugged from the ecu it shows its running pretty lean but when I go to richen it up the idle gets worse.
Im getting good, spark and fuel, the meter plate is fine and free. The car ran PERFECT before this issue so this is why Im thinking it might be the dpr.

How do you richen it up? What is the DPR idle current when the O2 is connected and what should it be?
With my VW CIS-E, if I set the DPR idle current to spec and then disconnected the O2 the AFR was just about 14.7:1 (.5V from the sensor).
Cold starting requires the cold start injector. Have you tested that? Cold idle after start is dependent on the CTS and the increased DPR current that it tells the ECU to supply initially. Depending on the DPR that could be as high as 75ma initially, dropping to the warm idle spec as it warms up.


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## johnnyGO (Feb 23, 2009)

but the a/f gauge shows its running super lean no matter how rich I try to make it


_Modified by johnnyGO at 2:15 AM 10-27-2009_


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## wclark (Mar 28, 2001)

*Re: (johnnyGO)*

So, do you mean it is running real lean while the O2 sensor is connected to the ECU, or only when the sensor is disconnected? Is your A/F gauge using the stock NB sensor in the car or a separate sensor?


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## wclark (Mar 28, 2001)

*Re: (wclark)*

By the way, from what I can deduce from what I read, I agree a very likely culprit is the DPR.


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## ziddey (Apr 16, 2006)

*Re: weird cis-e issue (johnnyGO)*

When you unplug the oxygen sensor, the dpr should goto 10ma with a hot cts. Is that happening?
Can you get the car to hold a stable idle with the oxygen sensor unplugged? Then, if you check the oxygen sensor voltage, it should be fairly stable.
The ignition timing isn't changing right?


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