[AC7880]

Very strange deal here. I changed the fuel filter as preventive maintainance. Just bought the car last week with 146,000 on it, and no record of a filter change in the receipts previous owner provided. Purchased NAPA silver fuel filter Number 23023. Free flowing when blow air through it (lung power).

Replaced old filter - new one is correct side up up (inlet outlet corret directions). Engine now running very high idle, idle drop is off, and some surging at the high idle under drop.

Tried pumping fuel through new filter into large jug - great fuel flow. Pulled old filter out of trash can and tried blowing through it. Extremely plugged, no flow, can barely force ANY air through it.

Old filter bad, new filter good, car running like sh#$. Tried idle adjust down - bottomed out and still no good. Checked all nearby vacumn lines in case I knocked one lose - no sign of it.

Last resort, pulled battery negative lead to let computer reset just minutes ago. Understand it must be no juice several hours to reset?

Any ideas - need car for work tomorrow. Hate to put the plugged filter back on - seems I'm asking to get stranded.

Thanks

 

[Bowlcut]

Very common i think. When you get mroe fuel the computer is used to a clooged filter and ends up idleing high. Mine idled high after i changed mine. Evntualy eric checked the idle and timing for me. That helped. But you have to follow the directions EXACTLY on how to adjust the idle. But if you did, you aac valve may be bad.... any other ideas.

 

[RPWSER]

I guess ill find out if this happens to me too, when i do my new filter tomorow. Courser, i was smart and bought a stock one

so maybe i wont have the same problems!

------------------
Ryan Walsh, 1997 200sx SE-R w/ ES mounts, JWT s4's, AEBS 4-1, PR CAI, Sportlines/AGX's, Bridgestone re730's, Matrix FSTB, Stillen GTR grill

 

[AC7880]

<font face="Verdana, Arial" size="2">Originally posted by Bowlcut:
Very common i think. When you get mroe fuel the computer is used to a clooged filter and ends up idleing high. Mine idled high after i changed mine. Evntualy eric checked the idle and timing for me. That helped. But you have to follow the directions EXACTLY on how to adjust the idle. But if you did, you aac valve may be bad.... any other ideas.</font>

I'll have to read up on setting idle correctly. Just turned the screw for now. Left battery disconected 15 minutes, re-connected and running much better. Will leave diconnected overnight and try in morning with fresh start.

Side note: on Sat I cleaned the throttle body and idle went up about 300 rpm, which I adjusted down with the screw. Ran great after wards. The old filter is WAY plugged - wonder if it did any damage to the fuel pump straining against the blockage?

The NAPA filter is a "stock" part (direct replacement versus upgrade).

Thanks for the advice - hope it settles out by resetting the ECU.

 

[Bowlcut]

Well just turning the screw will not set the idle. That is part of your problem. You have to disconnect the tps and the aac to set the idle. If not you are just fighting with the computer.... do it right. And you can always just reset the ecu with the diagnostic screw....

 

[AC7880]

<font face="Verdana, Arial" size="2">Originally posted by Bowlcut:
Well just turning the screw will not set the idle. That is part of your problem. You have to disconnect the tps and the aac to set the idle. If not you are just fighting with the computer.... do it right. And you can always just reset the ecu with the diagnostic screw....</font>

I'm new to the Nissan - went out and bought a Haynes manual (only one avail in town today). Manual is poor on info. Looked up idle adjust on SE-R mailing list archives. Did the idle hold etc, disconnected TPS - same problem. Tried disconnecting the AAC - with the TPS - still the same effect. Idle screw is bottomed out, min idle I can get is about 1700 RPM. What started all this is a new fuel filter (old one was plugged - much more fuel flowing now).
Book has no info - where is the ECU located on 91 SER, and what is easiest access to it so I can read codes? I had battery disconneted overnight to reset the ecu.

Thanks for any tips etc.

 

[Benito Malito]

Ecu in the 200 is under the center console. You can get at it from next ot the pedals and through the console if you take out the molding/ashtray and all that stuff. If you need to get at it alot go through the console.

 

[AC7880]

<font face="Verdana, Arial" size="2">Originally posted by AC7880:
Very strange deal here....
.</font>

Thanks for the replies. With your advice, and researching SER net etc the car is idling perfect and the timing is perfect.

Combination of fixes: read the codes off the ECU and reset it, lubed up the throttle, loosened throttle cable slightly, reset timing.

Looks like someone in the past compensated for the clogged fuel filter by tightenting the throttle cable to keep the idle artifically high.

I now know about the TPS, the AAC, how to adjust idle, how to set timing, where the ECU is, how to read codes off it, how to clear it. I think it was worth the time and effort, car running great. Timing was at 7 degrees, now 15 degrees. I have a pulley set to install in the next week or two as well as springs prokits and AGXs.

[This message has been edited by AC7880 (edited 05-03-2001).]