HAPPY HOLIDAYS. I HAVE A 1990 Q45 WITH OVER 200K MILES. I POSTED MY TROUBLE HERE EARLIER IN THE YEAR AND AM JUST NOW GETTING BACK AROUND TO THIS CAR TROUBLE. IT IS REAL SLUGGISH. ONCE YOU GET IT GOING IT SCREAMS. I HAVE CHECKED FUEL PRESSURE AND CONNECTIONS TO THE AIRFLOW METER. I HAVE CHECKED THE AIRFLOW METER FOR ANY " MISSES" WITH A METER AND DONT SEE ANYTHING. IM LOST. I DONT KNOW WHAT TO CHECK NEXT. I THINK IT NEEDS AND AIRFLOW METER BUT DONT WANT TO GUESS. I WOULD TAKE IT TO THE DEALER AND HAVE IT ANALAZED BUT DONT FEEL LIKE JUMPIN G THROUGH HOOPS WITH THOSE GUYS. NO CHECK ENGINE LIGHT IS ON.
ANOTHER QUESTION I HAVE IS THE DRIVE R SEAT ELECTRICS DONT WORK. I KNOW THAT THE MOTORS WORK BECAUSE WHEN YOU GET OUT OF THE CAR THE AUTO BACK MODE IS WORKING. ANY CLUES AS TO WHAT TO CHECK WITH THE DRIVER SEAT ELECTRICS WOULD BE APPRECIATED. THANKS IN ADVANCE. PEACE.
1990 Q45 Poor Performance
1990 Q45
IT STARTS FINE. IT DOES NOT HAVE AN "ELECTRICAL"MISFIRE. IT IS REAL SLUGGISH AT LOW RPM. IT WILL BACKFIRE INTO THE INTAKE IF YOU TRY TO GIVE IT A LOT OF "AIR" TO OVERCOMET THE SLUGGISHNESS. ONCE YOU GET IT GOING IT ACCELERATES FINE. WIDE OPEN IT SEEMS TO HAVE AS MUCH POWER AS IT EVER HAS. THIS SYMPTOM HAS NOT CHANGED IN 6 MONTHS. SPARKPLUGS ARE GOOD. FUEL PRESSURE WAS FINE WHEN I CHECKED IT LAST. IT SEEMS TO BOG DOWN WHEN YOU MAKE A TURN BUT I THINK THAT IS BECAUSE THE RPM GOES DOWN AS YOU SLOW DOWN. THE DRIVEABILITY IS POOR BECAUSE OF THE LACK OF POWER AT LOWER RPM.THANKS FOR YOUR TIME. PEACE.
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Chally
- Posts: 445
- Joined: Tue Apr 30, 2002 12:17 am
- Car: '94 Infiniti Q45
2002 Nissan Patrol 4.8L
2013 Citroen C4 (economy)
Caps still on... (means you're yelling, in internet terms)
CAS is Crank Angle Sensor. It's on the front of the engine on the drivers side, & has 4 wires going to it.
Make sure all the terminals on the CAS & Air Mass Meter are perfectly clean. If you are unsure of these 2 items, take it to a reputable workshop & get them to do it for you.
You may even have a damaged Air Mass Meter.
CAS is Crank Angle Sensor. It's on the front of the engine on the drivers side, & has 4 wires going to it.
Make sure all the terminals on the CAS & Air Mass Meter are perfectly clean. If you are unsure of these 2 items, take it to a reputable workshop & get them to do it for you.
You may even have a damaged Air Mass Meter.
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Mayhem_J30
- Posts: 2643
- Joined: Tue Apr 30, 2002 2:00 am
- Car: Ummm...My Car
- Location: Louisville, KY
Where would you purchase an air mass meter if you needed one? Do you know how to pull codes on this car? The check engine light is not on but there may be something stored that might give me a clue as to what is wrong with this Q45. Oh by the way you guys are pretty funny. I wish this was my moms car. She drives a MB 300d and i seem to be able to keep it going but the carpenters infiniti is keeping me busy. You know that something is funny with the economy when carpenters drive Infiniti's. Peace.
I have a 90 Q w/ 244k on it. At about 230k i had a very similar problem. Turns out my engine had WAY too much carbon buildup. About a week-long carbon clean was done on the engine and the power and lack of misses has since returned. Basically what the did is they removed the engine, let it soak with this solution (don't remember the name) that got the carbon out of the engine.
ok I have cleaned the connector on the cas. It was dirty and corroded. Similiar to the connector on the Air mass meter.Now the car really runs poorly and has a "bucking" in it under acceleration. Yes i hooked every thing back up but will double check after this afternoons hunt. Stay tuned for more Q45 performance woes from Austin texas. Hook em!
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Chally
- Posts: 445
- Joined: Tue Apr 30, 2002 12:17 am
- Car: '94 Infiniti Q45
2002 Nissan Patrol 4.8L
2013 Citroen C4 (economy)
I think it would be a good idea to get it to someone with a consult in your area.Is there anyone who may be able to help this fella?
I think you're on the right track, but there seems to be something not just right in either what you're doing or something else broken etc. (eg corroded wiring in the plugs)
Get a Throttle body clean, as suggested in earlier posts, as well.
I think you're on the right track, but there seems to be something not just right in either what you're doing or something else broken etc. (eg corroded wiring in the plugs)
Get a Throttle body clean, as suggested in earlier posts, as well.
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Ex-CA Driver
- Posts: 82
- Joined: Mon Oct 28, 2002 12:29 am
- Car: Speeding of course
I have tried to fix this car with help from this forum before. I just could not keep the car long enough to finish the diagnostics. We seemed to run out of time and money as there were some other repairs needed at the time. I have kept this car running for a friend for a long time as you can see by the miles. I am not sure if this was a progressive decline in performance or something sudden. We have cleaned the intake. We have tested the fuel pressure but may need to check it again. I am confused as to why the cleaning of the cas and i also cleaned the connector to the cam sensor on the left head. The performance got worse not better but it did change radically! This is a good strong running car in the past with very few service problems. It does have bosch platinum plugs in it i believe that are less than 15 k old. It has a new fuel filter. There are not check engine lights exept now that i had the sensor unplugged. I have not reset it yet. I only drove the car around the block after the sensor wire cleaning and it stunk. Thanks in advance for all your help. Peace.
it funny the guy who responded that replaced his fuel pump seems to remember the same symptom of it getting real sluggish after making a low speed turn. This car feels that way too but is it that the rpm is dropping or is it that there is a fuel pickup problem. seems like i drove this car with a gauge hooked up though and there was no change in the pressure reading while driving down the road. What sort of fuel pressure spec should i look for. back to the game. Hookem!
it funny the guy who responded that replaced his fuel pump seems to remember the same symptom of it getting real sluggish after making a low speed turn. This car feels that way too but is it that the rpm is dropping or is it that there is a fuel pickup problem. seems like i drove this car with a gauge hooked up though and there was no change in the pressure reading while driving down the road. What sort of fuel pressure spec should i look for. back to the game. Hookem!
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maxnix
- Posts: 22627
- Joined: Mon Jul 22, 2002 8:11 pm
- Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45
It does have bosch platinum plugs
Ooops. This could be bad news, and maybe even your problem. Search the forums for the reason why.
Backfire -- omminous. Backfire could be caused by bad valve timing. Uh-oh, have you replaced those timing chain guides? If this is the problem, the motor is in grave danger. Not something to play around with.
Low low-end power (also a potential valve-timing issue) -- the 1990 Q45 starts in 2nd gear. Sluggishness off the line is "as-designed" (that was how contemporary MB and BMW did it) but can be overcome with a '93 or JWT transmission controller, either of which gives first-gear starts. Compared to operation above 4000 rpm, operation below 3000 rpm will seem sluggish. Adequate for most situations, but sufferring greatly by comparison.
Did the person who last drove it regularly report a *loss* of power? If you are new to the car and accustomed to something less peaky, like say a Chevy V8 with 40% more displacement, you could be describing the way it's supposed to be.
Low idle in turn -- there's a switch in the steering that's supposed to cause the ECU to up the idle when the wheels are turned. Maybe yours isn't working?
Fuel pump pressure -- be aware that it's a unique 3-speed fuel pump. Last time it was replaced, was it replaced with factory-new OEM? Do you hear it operate 5 seconds when you turn the key from off to run without starting the motor? Does it hum or does it grind? This is one part it pays to replace before failure!
If you're going to work on the car, I highly recommend the factory repair book.
Low low-end power (also a potential valve-timing issue) -- the 1990 Q45 starts in 2nd gear. Sluggishness off the line is "as-designed" (that was how contemporary MB and BMW did it) but can be overcome with a '93 or JWT transmission controller, either of which gives first-gear starts. Compared to operation above 4000 rpm, operation below 3000 rpm will seem sluggish. Adequate for most situations, but sufferring greatly by comparison.
Did the person who last drove it regularly report a *loss* of power? If you are new to the car and accustomed to something less peaky, like say a Chevy V8 with 40% more displacement, you could be describing the way it's supposed to be.
Low idle in turn -- there's a switch in the steering that's supposed to cause the ECU to up the idle when the wheels are turned. Maybe yours isn't working?
Fuel pump pressure -- be aware that it's a unique 3-speed fuel pump. Last time it was replaced, was it replaced with factory-new OEM? Do you hear it operate 5 seconds when you turn the key from off to run without starting the motor? Does it hum or does it grind? This is one part it pays to replace before failure!
If you're going to work on the car, I highly recommend the factory repair book.
HERE IS AN UPDATE. NO IM QUITE FAMILIAR WITH THIS Q45. IT IS DEFINATELY BROKEN. WE ARE PUTTING A SET OF SPARKPLUGS IN IT TODAY. THEY ARE WORN OUT AND MAY BE THE CAUSE OF ALL OUR PERFORMANCE PROBLEMS. ILL POST AS SOON AS I AM ABLE TO DRIVE. WHAT CAN I EXPECT TO PAY FOR NEW TIMING CHAIN GUIDES PARTS AND LABOR ?
ANY CLUE AS TO WHY THE DRIVER SEAT DOES NOT WORK FROM THE CONTROLLER? IT DOES MOVE DURING THE IN AND OUT OF THE DRIVER SEAT TO ALLOW FOR ENTRANCE AND EXIT FROM THE CAR BUT NO OPERATION FROM THE SWITCH. THANKS IN ADVANCE AND HAPPY MOTORING.
ANY CLUE AS TO WHY THE DRIVER SEAT DOES NOT WORK FROM THE CONTROLLER? IT DOES MOVE DURING THE IN AND OUT OF THE DRIVER SEAT TO ALLOW FOR ENTRANCE AND EXIT FROM THE CAR BUT NO OPERATION FROM THE SWITCH. THANKS IN ADVANCE AND HAPPY MOTORING.
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maxnix
- Posts: 22627
- Joined: Mon Jul 22, 2002 8:11 pm
- Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45
I CAN'T HEAR YOU
Back to shouting, we see.
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maxnix
- Posts: 22627
- Joined: Mon Jul 22, 2002 8:11 pm
- Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45
Destined for Doom
Quote »it is still backfiring through the intake.....I am going to put some more miles on the car and see if it is different.[/quote] And the timing chain guides have been replaced? If not, you might be living on the ragged edge of an engine seizure.
I agree these sound like the symptoms of bad timing, but how in the world would a broken guide affect timing? The guide that fails is a tension-side guide. It's straight and should apply only a negligible force on the chain. It's just there to keep the chain from flopping around enough to derail. It doesn't take up the slack, does it? Perhaps we're looking at a stretched chain. Heath, did your chain actually jump a tooth?
on the road again! Hey guys thanks for your time and interest in my car problem. After a lengthy test drive I am convinced that this car is healed.Im not sure what fixed it. It was 6000 miles ago that i am sure that we looked at a sparkplug and decided that this could not be the problem. The sparkplugs(bosch platinum) were pretty worn out and showed some signs of oil deposits on them. By the way this q has been running bosch platinums for over 175000 miles. not the same set though. We put some denso platinums in it. The cas connector was real corroded as was the mas connector 6 months ago. This has been a real good car and relatively trouble free exept for a trans replacement at @175k miles. so thanks again and any one have any clue as where to start on the driver seat problem? Thanks. Peace.
Turn ignition on, push set switch, if memory light comes on for 0.5 seconds there is nothing set. If it comes on for 5 sec it has a setting in it. To set memory, turn ignition on, locate seat and steering wheel where you want them, push set switch then within 5 seconds push desired memory switch. Move seat manually then select the memory switch, seat should return to set position if the memory setting took. Be sure cancel switch below the steering wheel adjustment is off(out). Any time the battery is disconnected the seat memory will have to be reset.