94 Q Repairs Start Tommorow Open for suggestions.

[I_build]

132K have been experiencing slugish performance and hard starts when warm.

Fuel Pump buzzing, and error codes for KS & collant temp sensor (auxilary electric fan constantly running since CEL error.) Oil leaking around valve covers no plug change since 70k.

I put in the new pump, fuel filter, and air filter this morning, Put in a new MAF sensor & connector last month (needed it). Purchased all under plenum hoses, valve cover gaskets, plenum gaskets, pvc valve, knock sensors, & harness, and ngk plugs.

Vibration at 45 and 75 that I posted about previousely, prior responses to my post lead to rear trans mount as culprit (which will also be replaced tommorow) but I'm open for other suggestions about this vibration.

Any other suggestions that the tech might look at in conjunction with these repairs would be appreciated (while half my engine is apart).

Also... to add to my excitement.... if there are others that have been through this regiment comments regarding expected performance gains would be appreciated. Thanks.

[DAEDALUS]

Make sure to ohm all your injectors while you're under there. If any under the plenum are going out, you may want to replace them at the same time.I think you will be very happy with the performance gains once the knock sensors work and once the car is certain it isn't overheating. Did you ohm the temp sensor? It might just be a harness issue causing the CEL. I'm looking to do the same kind of work to my Q, but I'm in a little deeper--leaks from main seals and transmission, plus front engine mounts...guess what has to happen? I miss the performance.

[maxnix]

And move marginal injectors to the three locations they can be replaced without removing the plenum.
Modified by maxnix at 10:57 PM 3/26/2005

[JedCoop]

132K have been experiencing slugish performance and hard starts when warm.

I had a warm start problem that was an injector. For checking the injectors I found the highest resistance when the injectors are at their warmest. I saw my bad injector resistance climb steadily from 20 ohms to 55 ohms in just 10 minutes after the engine was tuned off. 6 of the other 7 did not increase at all in resistance.

The injectors are warmest after turning off the (completely warm) engine and letting it sit for 20 or more minutes. Leave the hood closed while you wait. (Your wait time may vary with ambient temp).

I believe the injectors warm up after the fuel stops flowing through them.

[DAEDALUS]

Did you observe this at the injector itself, or through the harness? Resistance in the coil will not change much with any reasonable temperature difference. Certainly not >100%.

[911/Q45]

Don't you think a failing injector might act like that Robert?

[DAEDALUS]

Not really sure--part of why I asked. I'm actually surprised that injectors fail gradually, at least past a certain point. I can see 14 ohms, maybe 15-16 ohms, but beyond that the odds would seem to favor a complete open circuit. Jed, if you observed the exact same behavior at the injector let us know. The reason I ask is that I've seen almost similar behavior once but it was the harness; the injector was fine.

[elwesso]

Not really sure--part of why I asked. I'm actually surprised that injectors fail gradually, at least past a certain point. I can see 14 ohms, maybe 15-16 ohms, but beyond that the odds would seem to favor a complete open circuit. Jed, if you observed the exact same behavior at the injector let us know. The reason I ask is that I've seen almost similar behavior once but it was the harness; the injector was fine.

Exact reason why if your going under the plenum its probably not a bad idea to replace the harness...... Its only like $20 from joe

[I_build]

Sat, Sun, Mon, & Tue... still at the dealership not done yet... 2 mistakes so far. 1 I didn't order the tran mount, and the dealership is charging 150 for the part, and the knock sensor coolant temp harness I got from Everything Infiniti is the wrong one dealer is charging 45 for the right one. The tech did not open it so I'll just send it back. Otherwise all other parts were correct (and a great price).

Funny thing is my loaner is a 2003 G35......... .... and I MISS MY 94Q. I was asked if I would trade (by a family member), and my answer was YES, and I'll sell the G35 to buy more Q's. Just getting over the seperation disorder ... makes me feel better to ramble. (BUT I MEAN IT)

[I_build]

Got my Q back yesterday (Wendsday). The total tab from the dealer was 1770$, parts were 850$ from Everything Infiniti, and the job was worth every penny. Ran the car across the Bayside Bridge @ 110MPH last night, and it felt like I could get out and walk along side because it was so smooth & quiet. I think someone mentioned that the difference between the car with bad knock sensors versus good was "effortless"... I couldn't agree more.

I also really appreciate the help that I got about my 45 & 75 MPH vibration in this forum since I bought the car 5 years ago. Someone suggested the rear transmission mount last week on this forum. Here's the funny thing... I directly aked the dealer to replace it, and now the vibrations gone. Three years ago that SAME dealer said the vibration was comming from the drive shaft and that it would need to be replaced (so I put up with the vibration because I didn't have over 1K to do the driveshaft). 250$ latter for the mount & install and the car has no vibration at All... That kind of pisses me off.

Any way other than that... the dealer did a great job I think for a fair price and this forum guided me through the necessary steps. Just a bit closer to restoring my Q. Thanks to everyone who helped.

P.S. I did have a small radiator leak, which the dealer quoted close to 800$ to replace (WHY???) is it that hard to replace? I think I saw the part for about 250$.... 550$ in labor??? sounds fishy... Any info appreciated. Thanks.

[maxnix]

Hopefully it was I who recommended the rear engine (transmission) mount replacement to cure your vibration at those speeds. Feel the same about the G35 also. Nice car. Love the Q.

Look to Joe again, or be very careful about after market. Some members have had custom build (stock is aluminum) radiators, including Q45tech by Griffin.

[texasoil]

Radiators.com has all brass radiator for your car --have had one in wife's 92 for 4 years now. A well built unit for $160. Installation took me about 45 minutes--and that's on a active car.

[I_build]

THANKS!!! I just contacted them and they will be calling me back. The price is awesome, and they do have a few versions, but I will ask specifically for the brass one. Thanks again.

[maxnix]

The price is awesome, and they do have a few versions, but I will ask specifically for the brass one. Thanks again.

Remember, stock is aluminum.