A few problems.....

[mtzgr777]

Got car checked out by dealership and this is what they came up with. I want to take each problem one step at a time, please advise what I should do first:

FOUND CODES P0340 (CAM SENSOR), P0325 (KNOCK SENSOR), AND P1705 (THROTTLE POSITION SENSOR). BESIDES THE FAILED SENSOR VEHICLE MISFIRES DUE TO BAD INJECTORS. TRANSMISSION ALSO SHUDDERS.

DIAG DIAGNOSED CONDITION AND FOUND MULTIPLE ISSUES. RECOMMENDED PERFORMING NO WORK TO VEHICLE AS IT WOULD EXCEED PURCHASE PRICE OF VEHICLE.

This seems like my car has a mess of problems, when really, the only issue I'm facing is loss of power during acceleration from a dead stop. ANY help will be much appreciated.

-mtzgr777

[goody90q45]

Ohm test the KS and Fuel injectors yourself with a voltmeter. It's very easy. Cluster of connectors is located at the passenger side end of the plenum.

For Fuel Injectors- Key off. Positive probe of meter to battery positive, negative probe to pin on connector. They should all be in the 10-14 ohms resistance range.

For KS- Key off. Negative probe of meter to battery negative, positive probe to the two lower pins shown in the pic. Both should read 550k ohms resistance. If they're dead you'll get a zero reading.

Checking these first will tell you a lot about what the ECU codes really mean. The 96Q engine is a different beast so the key may have to be on to measure resistance. Hopefully one of the 96 owners will help here. Good luck.

[Infinitiguy19]

There are ALWAYS two kinds of people in the world, In this case: Those who do things themselves and those who let others do the things for them. Take me for instance I was afraid to take off the throttle body, EGR and Idle Air Control Valve. But Mike and the rest of NICO showed me the way.

And the crank angle sensor code is new to me because you never mentioned it before.

FOUND CODES P0340 (CAM SENSOR), P0325 (KNOCK SENSOR), AND P1705 (THROTTLE POSITION SENSOR). BESIDES THE FAILED SENSOR VEHICLE MISFIRES DUE TO BAD INJECTORS. TRANSMISSION ALSO SHUDDERS.

DIAG DIAGNOSED CONDITION AND FOUND MULTIPLE ISSUES. RECOMMENDED PERFORMING NO WORK TO VEHICLE AS IT WOULD EXCEED PURCHASE PRICE OF VEHICLE.

-mtzgr777

Is that exactly what the Tech said?

If so well the dealership has alot of overhead (Bills to pay) so obviously they have to cover there costs like I said. So of course they are gong to say $6000 to fix that. Like I said when they pull the plenum they don't change one thing they CHANGE EVERYTHING.

And if indeed the transmission does shudder it maybe the transmission mount. But you have enough problems to deal with as it is.

And like you said you want a car to drive, and you just want it to work...But the way I see it I drive a $50K car everyday and I treat it as such (Except on my bad days and on the highway.)

But if you do indeed have a Crank Angle Sensor code then the CAS should be replaced with a new one or low millage used one. Knock Sensor you ALWAYS need NEW. Throttle Position Sensor may just need to be adjusted or you can replace it with a new one or a low millage used one.

[mtzgr777]

Yea it was news to me too about the CAS sensor. And yes, I copied that exactly from what the Tech gave me.

[Infinitiguy19]

Well when it comes to the crank angle sensor you maybe a little lucky because 1994 (11/1993) to 1996 will work on your car. And that leaves alot of possibilities. There is also the problem of installing it which requires a Nissan Consult or marking of the screws EXACT original position.

Here is your part number for the Crank Angle Sensor: 23731-67U01-

See if Mike (Goody90Q45), DrewQ45, Dsagers...) Has one or just keep checking the classifieds every now and then. But your car is still drivable with it being bad I see.

I will make a video on how to check the ECU codes tomorrow.

[mtzgr777]

Yea, it's still drivable alright. That video will help a ton thanks. What do you mean it laves a lot of possibilities?

[Q451990]

For Fuel Injectors- Key off.

Actually from '94 or '95 up the key should be on... Nissan switched the injectors to a switched circuit at some point around there. Or you could just read the resistance through the other connector that feeds the positive voltage to the injectors.

Heath

[elwesso]

Actually from '94 or '95 up the key should be on... Nissan switched the injectors to a switched circuit at some point around there. Or you could just read the resistance through the other connector that feeds the positive voltage to the injectors.

Heath

94-96 injectors are all the same and are tested with the KEY OFF...

[Infinitiguy19]

On 1995 and later Q45s, you may need to turn the key to "on" because the injectors are on switched power.-JG

If thats the case then this part of Q45.org should be removed so others won't become confused.

[Victor]

You should never check resistance with power applied to a circuit. You will burn out your ohmmeter. This is just a general rule, I don't know if the key should be on or off.

[Q451990]

It might be worth making a new picture showing how to test through the harness on both sides, so that the process is standardized for all G50s. Which reminds me... I wanted to hack the harnesses off of a Q in the pull-a-part so that I can use them to make test plugs

Heath

[silkysmoothyjud]

Just fix the injectors and the KS, it may clear the other codes. TPS? CAS? Would the car even run? Transmission shutters? Did they try and sell you a car? I dont trust dealerships at all. My Q sat for about a year while I read this site and repaired her. My best advice is to find a local mechanic that will let you watch the plenum being removed and reinstalled. Once you see it, you wont fear it at all, its actually not that bad....

[mtzgr777]

Are the KS and Injectors somewhat near each other, so if I do have it fixed, the labor wouldn't be too much more for both? I just wish some mechanics and or dealerships actually respected my car. All four places I've been to say "It's not worth fixing up something that's worth so little" or "That's why these cars are so cheap, no one can afford to maintain them."

[qship96]

Are the KS and Injectors somewhat near each other, so if I do have it fixed, the labor wouldn't be too much more for both? I just wish some mechanics and or dealerships actually respected my car. All four places I've been to say "It's not worth fixing up something that's worth so little" or "That's why these cars are so cheap, no one can afford to maintain them."

The correct way to do it is to purchase the complete "under-plenum ultimate kit" from Joe and replace everything under the plenum.....all hoses,gaskets,knock sensors and harness,etc are included in the $900 kit and labor will add aprox $600 bringing total cost to $1500.......anything less just creates further problems and repeat labor. This has been discussed over and over and over on Nico for years,and proven by those who try to take shortcuts to save $$$ over the years.

[silkysmoothyjud]

I wish you lived close by, I'd do it for a couple hundred bucks and a case of beer. I can remove that plenum in about 15 minutes now.....

[mtzgr777]

The correct way to do it is to purchase the complete "under-plenum ultimate kit" from Joe and replace everything under the plenum.....all hoses,gaskets,knock sensors and harness,etc are included in the $900 kit and labor will add aprox $600 bringing total cost to $1500.......anything less just creates further problems and repeat labor. This has been discussed over and over and over on Nico for years,and proven by those who try to take shortcuts to save $$$ over the years.

That doesn't sound too bad to me. So you're saying that entire kit will only take a mechanic about 6 hours to put in? Is that for someone who's worked on Vh's many times before or any mechanic?

I wish you lived close by, I'd do it for a couple hundred bucks and a case of beer. I can remove that plenum in about 15 minutes now.....

I wish I did too
Modified by mtzgr777 at 8:33 AM 10/31/2009

[Q451990]

The cost estimate above does not include any injectors that you need to replace. I think 6 hours is pretty tight estimate unless you're dealing with an experienced technician. Have you ohm tested your injectors yet? I spent about $3K just in parts to do all of this last year, but I was converting from phase 1 to phase 2 injectors, so I had to buy new fuel rails - which added a couple of hundred to the cost. I also replaced all 8 injectors, and you may be able to get by with just one or two...

Heath

[mtzgr777]

No I don't even own an ohmeter, I'll go buy one later today. This might be a stupid question, but if my car is saying that the injectors are bad, doesn't it mean they are, so what's the sense of testing them? (I'm not trying to be rude I just don't understand...)

[Q451990]

Unless you're replacing all 8, you want to know which ones are bad.

Heath

[mtzgr777]

Got it.....I'll Ohm them later and get back with the results. One quick question, you guys keep saying Ohm them with the Key Off, you mean with no key in the ignition, or the key in the ignition but to the off position?

[goody90q45]

no key

[mtzgr777]

Got it....... thanks

[goody90q45]

.....but if my car is saying that the injectors are bad, doesn't it mean they are, so what's the sense of testing them? (I'm not trying to be rude I just don't understand...)

The codes you're getting are all related and it's probably one event that is setting off all 3 at the same time. My guess is the stealership didn't ohm test the injectors or KS or they would have told you which ones were bad and supplied the readings.

Ohming the KS tells you whether they're dead or just reacting to the "event" and letting you know they did their job. If they're dead the code will come back as soon as they're cleared. The 96Q seems very sensitive to a dead KS so I'd be checking these first. See posts by Alexander (username) about his 2 year and $10,000 struggle to solve similar issues to your.

Ohming the fuel injectors will help pinpoint the problem as Heath implied. No sense replacing all 8 injectors when only #2 might be bad and can be replaced in 15 minutes.

You can buy a code reader off ebay for $30 and pull the codes yourself. It pays for itself the first time you use it.

Ohming KS and FI is simple and is something every NICO Q owner needs to be able to do.

[mtzgr777]

Sorry guys, I guess I'll have to do it tomorrow. I bought a 15 range digital Multimeter (Hopefully this is the right one) at RadioShack but it needed some retarded midget battery that I couldn't find anywhere else and they closed right after I left I guess because it's Halloween.

[silkysmoothyjud]

Im not sure if it is the injectors or the coil packs on a 96, but if you are doing injectors, only do the four under the plenum. Leave 1,2,7,8 alone for now (injectors are $$$$), as you can reach them w/o removing the plenum. ONLY LEAVE ONE SCREW (the screw on the left if you are looking at it from the hood) in injector #7s harness so that you can access it w/o plenum removal later on down the road. Do the KS, said four injectors, the gas lines on the fuel rail and the gas line on the Fuel Pressure regulator. At that mileage, you will be glad you did....

Oh yeah, there is an air hose on the back of the plenum attached to the Idle screw box (AIC), it is a tri hose (3 ended hose). Be care not to split that hose (50 bucks). When you button that hose back up, use hose clamps that are adjustable by hand, it will make plenum removal easy in the future, its my secret to a 15 mintue removal.....

[mtzgr777]

What would happen if I only replaced injectors 1,2,7 and 8 for now and some time down the road have the rest done. I'd like to do it myself but I'm only 17 and it seems wayyy too complicated for me, I don't even know where to start.

[Infinitiguy19]

Injector Replacement

1) Remove blue 15amp fuel pump fuse from fuse array near the hood pull handle.2) Start the car and let it die. Then crank it several more times.3) Remove the front plastic trim cover right in front of the plenum...3 10mm fasteners.4) Cut off the short length of fuel hose right behind the trim and drain the fuel rail into a container. You may even want to blow the rail out with compressed air at 30psi, but it's not necessary. Obviously you'll need a length of fuel injection hose to replace the removed one. Take precautions against fire.5) Carefully remove the metal harness clip from the injector's harness connector.6) Pull the harness off the injector.7) Remove the 2 screws holding the injector cap down. Careful, they're on pretty good and easy to strip. Some techs replace them with hex-heads.8) Remove the metal spacer from under the cap.9) The old injector can be pried and/or pulled out. Make sure you remove both o-rings. If you drained the fuel rail properly, very little fuel should drain into the intake runner. Whatever fuel drains down will end up in the oil pan and thin out the oil. 10) Place the new o-rings on the new injector and place a bit of grease on them.11) Push the injector into the fuel rail, orienting it like the old one, and being careful to not pinch either of the o-rings.12) Replace the spacer, noting flat-side orientation, and fasten cap down.13) Place the clip on the connector first, and then place connector on the injector.14) Install new fuel injection hose and replace plastic trim.15) Install pump fuse.

Make sure the engine idle's smoothly and keep an eye on the exhaust for excessive white smoke. If you get a lot of fuel drain down into the intake, don't crank the engine till you're sure the gas is out of there, and change your oil soon.

Quick Plenum Pull:

Remove intake stuff --- bolts that connect to runners--on the rear Y hose just remove clamp on passengers side leave others on ,, use small pry bar (6-8") Pry Y hose end off --- usually comes off almost easy... and not hard to put back on either. Lift plenium up slighty at angle (higher side being the throttle body side ) remove remaining vaccum hoses.. Done!. BTY it's an hour or less to remove

Fuel Injectors Warning very bad experiences with rebuilt injectors as all they do is change the bad coil [solenoid]and clean the already worn pintle so they leak ! Most rebuilt parts are designed to last just 1 year or 12,000 miles at best [for used car dealers to sell you a working car]. Only buy new injectors [$150 TJ] please so you don't have to pay the labor twice.

If you bought injectors and gaskets [plus plenum middle gaskets from TJ you might save $50x8=$400 plus $25 x 6= $150 labor or about $550. But while an easy but time consuming job, if you haven't changed 6 PVC, plenum water hoses, fuel and vacuum lines or checked knock sensor harness or sensors: be prepared to do at same time as you don't won't to pay same labor again [these extra parts are around $600]. Are you sure all injectors are bad? Usually just one or two unless really bad gasoline. The 12 ohm test will usually work. My 90 at 207,000 still has OE injectors but all hoses were replaced at 80,000 - 120,000 miles probably time to consider it again [they last longer in colder climates].

Any sensor input that results in a rich mixture can cause an injector leak code. The best way to resolve a code 45 on these vehicles in addition to the injector leak down test is to carefully check the Mass Air Flow Sensor, coolant and 02 sensors along with a fuel pressure regulator test. You said the fuel trim was running rich!

I have seen the internal seals on injectors fail allowing gas to seep through the injectors. Look into that as well.

Since each injector cost $150 plus the plenum removal charge $500 you don't want to replace unnecessarily. [$1700 total] A smart technician can if inclined examine the waveform [current and voltage] of each injector and determine a lot but will you pay $400-$500 [5x$80/hr]for some research on top.....very few of us are smart enough to predict the future [the week] of a component failure or say with any kind of certainty that another one will not fail soon.

The injectors are $160 x2 = $320 plus the rest of the job is removing the plenum, replacing them, and 8 new plenum gaskets plus all the hoses that usually break from age and putting things back together. We would probably charge around $750-$850 depending on what else broke [hoses]. This job has only about 2 hours of common labor with the full chain and guide replacement [$2500] and none with the simple guide replacement, however you should be able to get your plenum water and fuel hoses replaced for maybe 1-2 hours more labor. If you are paying to take the plenum off be sure to check the knock sensors and harness while they can be easily changed [$400]. Personally I would attempt to get the Infiniti tech to moonlight at $45-50 hour and buy the parts from TJ. That said are you sure you have bad injectors a ohm check not the Consult is the way to confirm this along with the power balance test, were your plugs replaced at 120k.

Crank Angle SensorWe've discussed the intermittent connectors on the crank angle and MAF sensors. Over the last year we have found 2 intermittent crank angle sensors themselves. We are not sure if it’s the socket, LED or the photocell/amplifier pulse shaper module but the ECU is supposed to go into fail safe [allowing the engine to keep running somewhat] but it doesn't .......a new sensor seems to fix it....in any event the sensor is non repairable as yet.

You are correct 0802 points towards crank position sensor. Check the connectors to see if they're not corroded or loose. Infiniti calls it a magnet sensor & it's located near the flywheel. List $36.85 Cost $27.64

I have more info let me know if you need it.

[Q451990]

You need to replace the injectors that are out of spec. - which may or may not be the ones you can access without pulling the plenum.

Heath

[Infinitiguy19]

Acoording to JP his car idles almost perfectly. So that would rule out the injectors I think, But then again he has'nt driven a restored Q. But if I were JP I would test the injectors but not lose any sleep over them. Because he went to a dealership after all and they would want to replace EVERYTHING to be safe.

[silkysmoothyjud]

Yeah, the stealer will replace everything to get paid.....Good news is, the coil packs fail more than injectors on a 96...

BUt injectors are easy to replace:start car then pull fuel pump fuse while car is runningremove gas cap to depressurize systemremove injector coverremove injector with a big flathead screwdriver (put flathead under the injector connector and turn it like your screwing something in) and pop it out...simple removal

put vasiline on oringsuse a screwdriver and a hammer and tap it back into the holereplace cover.put fuse back incheck for leaks....its that easy and some places will charge 500 to do an injector that is accessible w/o plenum removal...