Rough idle

[sjava]

Hi,

Thank you all for good suggestions and great write ups you pointed out. I finished changing all the injectors in my 94 Q45, installed a new fuel filter, changed driver side valve cover gasket, PCV vaule, cleaned the throttle boday EGR and tube, and IAC. Spark plugs were changed couple of month ago. The engine started right up and ran very smoothly at around 1200 rpm and settled around 1000 rpm after it warmed up. I expected the idle speed of 650RPM as it used to be. I checked the accelerator cable and it had slack. I end up adjusting the idle speed to 650RPM by turning the IAC screw clockwise but the engine got a bit rough so I raised it to 700RPM which is better but still some noticable engine vibration at idle. Is there other ways to adjust the idle speed? any comments why the idle speed went up that much after injector work?

Thanks a lot

[maxnix]

IAC is usuaully misadjusted by mechanic to compensate for dirty intake path.

You should be 2.5 - 3 turns out. Use a real Consult, not car's tachometer to determine idle.

[Josey92]

Hi all! I am new to the forum as I specifically registered to find out more about the "rough idle" problem with the 94 Q. The vehicle in question is actually my father's but I am thinking of buying it from him at about the trade in value of $5K. It's got 58K miles on it and it's been well taken care of and not driven in the MI winters. It now resides in Las Vegas.

So, anyway, 2 injectors have been replaced and it still suffers from the same problem. The same shop is now stating, after an ECU read, that it needs about an addtl $3K in work. On the plus side, the shop is not trying to pull a fast one because they also state that it's not worth the cost to fix it. They are saying that he should trade it in for a new vehicle so that he can get the $5K out of it.

Sorry for the long post but here come the questions:1) can he get $5K trade-in value with this problem?2) can the changes that sjava put into the fix be done as a DIY and for how much (appx).

I know that the fixes done by sjava are not a guaranteed but I would like to see if it works.

BTW, prior to this problem, all maintenance was done by a Nissan dealer.

This site is a great resource and I look forward to replies and hopefully being a fellow owner.

[AlabamaDan]

Some of the other guys around here can give you lots of technical advice on how to get a Q running perfectly and most of it is DIY with their help. But, $5k for the car sounds a little high.

Q45Tech says all Qs need about $3k maintenance. So that's normal I'd guess.

Welcome to NICO!

[captainluigi]

josey92, i can only address the trade value of $5k. thats entirely possible as trade-in value is all smoke, a little mirror work and something we used to call ''pencil whippin''. in plain lingo, they can show you just about anything. if you want to you could negotiate the deal as a cash deal then when you've arrived at a # everybody can live with bring in the trade then. i think you'll find a different scenario at that time.

bueno suerte