Consul Question

[duck3986]

Last week I wrote about my sluggish '98Q. I cleaned the MAF and it seemed better, but I think the issues comes and goes a bit, getting worse in warmer and more humid weather.

Which is leading me to think I may have a bad knock sensor.

With a multimeter, can I check the sensor without removing the plenum (is there 1 or 2 on a '98?)?

I haven't had a check engine light come on. If I bring it to my Infiniti dealer and they run a diagnostic on the engine, can I expect a full analysis of the engine.......timing advance, rich or lean, coil strength for each cylinder, etc?

This sluggish feeling reminds me of a car with a plugged catalytic converter or a carbeurated car with the choke on or a vacuum issue.

Thanks,Don

[911/Q45]

The dealer can tell you plenty with a 1 hour Consult session. Money well spent, go for it.

[maxnix]

If I bring it to my Infiniti dealer and they run a diagnostic on the engine, can I expect a full analysis of the engine.......timing advance, rich or lean, coil strength for each cylinder, etc?

Yes, get a full print out and post it.

[Q45tech]

Since it is OBD2 [96 and later] you just use your own in expensive scanner.

Don't assume the technican knows much beyond go no go readings. What you want are acceleration data logging of parameters. Hard to do inside a dealership as it requires multiple SAFE zero to say 60 mph accelerations .......logging different data at each run.........never done as far as I now at dealers.

[duck3986]

That's great information. That's what I was afraid of, that a tech would just hook up a scanner and tell me I have no codes.

That won't help me. I need to know what's happening as the car is being driven.

Is there software that can be bought, installed on a laptop and connected to the car's computer for my own analysis?

[DAEDALUS]

Do a google search. There are quite a few, with varying levels of price/features.

[duck3986]

On a '98, does the plenum need to come off to replace the knock sensors?

Do they typically start to fail at a certain mileage or do some last forever?

If you remove the plenum, is there any other maintenance items worth replacing at 90k miles?

[maxnix]

You can get a manual at http://www.nissan-techinfo.com/infiniti/ and all TSB (there are a ton of them!) for a one day subscription of $20.

Yes, the plenum needs to be removed. No, it is not as involved as a VH45DE.