Help with J30 sluggish engine

[hkchuen]

My J30 has developed the following problem recently:

Sometimes the check engine light comes on at startup. Then, if I restart the car, it may disappear. When the CEL comes on, the car shakes a lot even at idle.

The CEL light comes up some times when I am driving at the freeway; again, wherever it comes up, the car shakes.

Apart from the CEL, I also notice a very signficant loss of power. The car is very sluggish now and has problem accelerating.

Any help is deeply appreciated. Thanks!

[Defiant]

Get the CEL code read, and go from there.

[hkchuen]

I have just gotten my CEL code checked. The only code that appears is the knock sensor... which should be unrelated to my problem. The following are the symptoms:

(1) The CEL light may comes up at startup. At that time, the car shakes and idles around 500rpm. If I restart the car, someitmes the CEL may go away.

(2) THe other occasion the CEL will come on is when I am on the freeway and step on the air. The car will downshift to passing gear and then suddenly lose power; then the CEL comes on and will remain on for a long time. At that time, the car will shake; it shakes the most at idle.

(3) Even when the CEL is not on, the car runs very sluggishly.

(4) The other occasion problem is, when the car idles at "P". The idle rpm may stay at 2000rpm and the engine gives out a lot of noise.

Other information:- new air filter- a bottle of chevon techron put in

[hkchuen]

Just wondering... do anyone have an idea?

[Q45tech]

Obviously the knock sensor and harness and O2 sensors normal things to replace every 100k/7 years..............plus a good induction [TBs and runner clean].

[hkchuen]

Thanks! What is a ball-park figure for the labor cost of replacing the knock senosr and the O2 sensor? I will most likely buy the parts myself.

[hkchuen]

Just got back from the dealer.

They say that the problem is caused by bad fuel injectors. Does it mean that I should do a "fuel injection cleaning" or should I replace the fuel injectorrs?

[maxnix]

Try a can of BG44K first.

If better but still not good, do the rail flush service, all above assuming the injectors are in resistance specifications.

Can you get the dealer to define "bad fuel injectors" or result of power balance or ohm testing of each?

http://www.bgfindashop.com

Call first to see what exact service each shop offers.

[hkchuen]

The dealer refused to tell me which one is bad; they want to replace all 6 fuel injectors, quoting me a price of $1883, which includes 6 hours of labor.

They also say that it needs "cam seals valve cover gasket crank seal" because the car is leaking oil... is this cheap to fix? Do I need to fix it?

Bottom line is, the service manager walked out with the used car manager and told me that they are "willing to take my car for free" so that it is "more convenient" for me!

I figure it is probably the last time I am going to the dealership. I guess I will just come here for help... thanks guys

[maxnix]

If your J>1995, get an OBD II scan and report back.

If your J<1996, look for an local Z32 tuning shop that has a Consult I and have them run a diagnosis.

Report back. Dealer sounds like an A-hole.

[Q45tech]

Since Philly and NJ/NYC are now using ethanolized fuel [since May 06] not unusual to see injectors failing from purchased water in fuel and the shock of ethanol reacting with residue MTBE inside hoses etc. [first refill following change over].

In theory the dealer is correct all probably will need changing eventually.

Dealerships get tired of doing free diagnostics and then having clients go somewhere less expensive for repairs .... why they charge an hour or two for diagnostics.

We always credit part of diagnostic time if repairs are done at one of our 3 shops.

[hkchuen]

Thanks! I called the dealership on the phone again and told them what I heard on nicoclub about the "power balance" test and the "ohm test". This time they give more information and said that all the injectors look good on the ohm test. He said that they give the right resistance.

However, he said that the "seats" for the injectors #1, #3, #4, and #6 are bad.

For the power balance test, he said that his guys did not save the output...

I have never heard of "seats" for injectors before. What are those?

(Mine is a 1994 J30; I live in zipcode 19020, PA... any suggestion on "Z32" tuning shop around this area?) Thank you so much.

[maxnix]

Maybe he is referring to the O rings.

Learn the benenfits of ISO-HEET (not HEET) in every tank if you are using ethanolized gasoline.

If I were you, I would schedule a trip to

Keith Vanmeter Auto Repair(856) 415-2022395 Wenonah AveMantua, NJ 08051

You will be glad you did.

[hkchuen]

Thank you very much for recommending a mechanic! I have been looking for a reliable mechanic for a long time.

[hkchuen]

I am a little confused now. Here are the information, according to the dealer, that I summarized:

[1] There is an engine code (as can be seen from the figure attached above) for knock sensor, and for "Injector-Open" (it says 4 times, I am not sure what it means)

[2] The dealer says that it passed the ohm test, i.e., each injector has the right resistance.

[3] They say that the "seats" are bad, for injector #1, #3, #4, #6; probably they mean the "O-ring".

Now my confusion is: Does it mean I should replace those injectors, or only their o-rings?

[DominickJ30]

Seats are not O-rings, o-rings are o-rings.

The seat is the part where the valve SITS when closed.

This meaning that when your injectors close they never fully close. I would say if you are doing that much, might as well do em all.