94 Q45 Check Engine Light is on...

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aliciaford
Posts: 77
Joined: Wed Aug 06, 2008 10:25 am
Car: 1994 Infiniti Q45

94 Q45 Check Engine Light is on...

Postby aliciaford » Thu May 27, 2010 2:50 pm

Ok, so recently had an oil change, tranny flush, replaced fuel pump, fuel pump oring, ect. Car was running awesome but had a ever so slight hesitation between 45-50 mph. So, my mechanic recommended that I run a can of BG 44k through it and see what happens. I hesitated for a week or two, then I experienced the car shaking when I was stopped at a red light. Thought it was odd, so I went out and bought a can of 44K. Put it in the tank, everything was fine, now at 1/2 tank and I started the car and it is shaking violently and check engine light is on. Mechanic scanned it and said its getting a injector open and knock sensor code. Ideas? Could it be the BG and not an injector? Car has 130,000 miles on it, and we have already replaced MAF, cleaned TB, ect. Just wanted help on where to start.....

Thanks
Alicia


aliciaford
Posts: 77
Joined: Wed Aug 06, 2008 10:25 am
Car: 1994 Infiniti Q45

Re: 94 Q45 Check Engine Light is on...

Postby aliciaford » Thu May 27, 2010 3:08 pm

Ooopps,forgot I also had both valve covers replaced and new platinum NGK plugs about $1500 and 60 days ago.

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Infinitiguy19
Posts: 7758
Joined: Sat Dec 22, 2007 4:58 pm
Car: 1993 Infiniti Q45 188580 Miles
1994 Infiniti Q45a 240000 Miles

Re: 94 Q45 Check Engine Light is on...

Postby Infinitiguy19 » Thu May 27, 2010 3:17 pm

Did you replace the MAF sensor with a known good one?

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goody90q45
Posts: 3673
Joined: Wed Aug 17, 2005 2:07 pm
Car: 1992 Q45 (sold)
Location: Orangevale, CA

Re: 94 Q45 Check Engine Light is on...

Postby goody90q45 » Thu May 27, 2010 9:00 pm

aliciaford wrote:....... Mechanic scanned it and said its getting a injector open and knock sensor code. Ideas? Could it be the BG and not an injector?.....
Got a voltmeter? (Radio Shack $15) It's time to ohm test your injectors and knock sensors. It sounds like you have a couple of fuel injectors on their last leg. Hopefully the KS code is caused by the injector code but ohm testing will tell you for sure.

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aliciaford
Posts: 77
Joined: Wed Aug 06, 2008 10:25 am
Car: 1994 Infiniti Q45

Re: 94 Q45 Check Engine Light is on...

Postby aliciaford » Fri May 28, 2010 8:51 am

We will go get an Ohm meter this am and check it out. Just cant help thinking the car ran good before I put that BG in the tank. Keep wondering if the BG was bad.... Also, the MAF was done at Infiniti of Fife, so I am sure it was new OEM. Should it test out as an injector failure, should I go with new OEM or is aftermarket good quality. My husband tested the battery yesterday as well, seems to be on its way out, so I have a new Optima coming this am just to be sure. He indicated that he thought it smelled like gas in the car also.... Hmmm.

Thanks guys

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goody90q45
Posts: 3673
Joined: Wed Aug 17, 2005 2:07 pm
Car: 1992 Q45 (sold)
Location: Orangevale, CA

Re: 94 Q45 Check Engine Light is on...

Postby goody90q45 » Sat May 29, 2010 5:09 am

aliciaford wrote:.....He indicated that he thought it smelled like gas in the car also.... Hmmm.......
Take a sniff in the trunk and see if the gas odor is stronger there. If it is, the stealership may have misaligned the fuel pump o-ring, reused the old o-ring (it swells), or stripped one or more of the screws installing the assembly back in the gas tank.

If the odor is coming from the engine compartment it's probably a clamp needing retightening on a fuel hose. Look closely with a flashlight tracing the fuel hose inlet path from the filter to the injectors and exiting out the DS rear under the plenum. The most likely source is going to be the hoses at the rear of the fuel rail. Your description of the problems didn't sound severe enough to think an injector lower o-ring had sprung a leak and was close to hydrolocking the engine.

The injector ohm readings will tell you a lot about what's wrong with the engine and the reason for the codes. Start with the readings and depending on which ones may be bad go from there. Hopefully you're taking the readings yourself and not paying someone. It's easy stuff and won't take you 5 minutes to complete.

Still enjoying your $100 Q? I forget the circumstances....was it a flooded engine or bad fuel pump that the shop couldn't diagnose and the owner gave up on? Before you know it you will have spent the $3000 on repairs that's rumored to be the norm. Hopefully you're still happy with it.

Q45tech
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Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl

Re: 94 Q45 Check Engine Light is on...

Postby Q45tech » Sat May 29, 2010 6:31 am

Rumors, heck we have documented files on hundreds of Q45 customers since 1995.
Once you get above 50 units of each year Statistical anaylsis is your friend especially in the same State or enviromental area.

Unfortunately 95% of Older Q45 customers have abandoned ship, being unwilling to layout the cost of system rebuilds. {engines, injectors, transmissions,

aliciaford
Posts: 77
Joined: Wed Aug 06, 2008 10:25 am
Car: 1994 Infiniti Q45

Re: 94 Q45 Check Engine Light is on...

Postby aliciaford » Wed Jun 02, 2010 2:34 pm

Ok, so heres an update... So, replaced the fuel pump o ring for the second time and all new screws. Screws were horribly stripped and o ring was shot. Problem seems fixed there. Then, we replaced the battery and my husband barely touched the fuel line that comes off the top of the fuel filter and fuel started spraying everywhere! So, replaced those hoses which were lose, cracked and seriously worn. Problem fixed, right? NO... still idling rough, seems fine driving down the road but as soon as you give it gas you feel the rough again. Yet, if its in park is seems to really improve, idle is higher about 700-800 rpm and if you put it in gear it drops to about 400 instantly. Does this sound like an injector? Off to radioshack to pick up a volt meter...we will see.

Oh, and goody I love this car! It was just flooded, and when its running right I giggle a little when I drive it thinking of the $100 deal I got. Hubby says its no deal, just another [email protected]#$% Infiniti problem... what does he know. ha ha. Sold the 90 for $2200 and we have put $2200 into the 94, so I am only out the $100 so far unless it is an injector...or two. Are they easy to replace yourself and does OEM matter or is BOSCH ok? Dumb question, I know OE is always better but thinking BOSCH maybe makes it for Nissan?

Thanks guys
Alicia

qship96
Posts: 6624
Joined: Sun Nov 24, 2002 11:31 am
Car: 1996 Q45

Re: 94 Q45 Check Engine Light is on...

Postby qship96 » Wed Jun 02, 2010 5:25 pm

Consider the $2300 spent so far as just the initiation fee!!!!! Ongoing monthly dues will be 200-300 per month, every month you own the beast.

aliciaford
Posts: 77
Joined: Wed Aug 06, 2008 10:25 am
Car: 1994 Infiniti Q45

Re: 94 Q45 Check Engine Light is on...

Postby aliciaford » Mon Jun 14, 2010 12:16 pm

Update... So, several of the screws for the fuel pump were stripped along with the o Ring being misaligned. Replaced all screws and new Oring. Still ran horrible...so we ohmed the injectors, all were within range... So, checked the fuel lines. One line sprayed like a gyser a foot in the air when I touched it...it was cracked. So, replaced it, tightened all clamps. Great... go to drive it, still runs like sh**. I go home totally defeated, thinking....why did I buy another Q? Hubby is irritated to say the least, I finally decide to just sell it. Go to leave for work, start the car....purrs like a kitten ever since. :wtf2: Not that I am complaining but just wondering if it took a few starts for the computer to reset or what? A new antenna and knock sensors to go and then just try to get her from me..... :chuckle:

Thanks

qship96
Posts: 6624
Joined: Sun Nov 24, 2002 11:31 am
Car: 1996 Q45

Re: 94 Q45 Check Engine Light is on...

Postby qship96 » Mon Jun 14, 2010 12:27 pm

Welcome to old lux. car ownership.........it never ends, requiring a steady infusion of time and money to keep on the road. Probably less expensive to lease a brand new Corolla or Sentra if you really look at ongoing monthly repair/parts replacement costs over time and include gasoline costs into the equasion !!!!!!


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