hello;
I have a 1993 (i think, has a 1994 owners manual, dual airbags and dual seat heaters, which i find curious) J30 that i have owned for about six weeks. Love the car, but i have noticed one potential problem. When the car is running in Park, the engine speed seems to surge in a regular pattern. I can feel it and can see it on the Tach. Generally, it will run normally at about 650 on the Tach and then about 45 seconds later it will increase to about 900-950 on the Tach. I can also clearly feel the surge in engine speed. This also occurs when I'm in Drive and could be a safety concern as i have to hold the brake down fairly hard at all times or the car will surge forward. This happens all the time. The vehicle has about 80,000 kms on it (under 50,000 miles). I don't know much about cars and I'm hoping that i can use the friendly and knowledgeable people on this board for some advice. thanx.
J30 Idle Question
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Mayhem_J30
- Posts: 2643
- Joined: Tue Apr 30, 2002 2:00 am
- Car: Ummm...My Car
- Location: Louisville, KY
welcome back gdude. I think you start looking for the problem with either your Mass Airflow sensor or your throttle position sensor.The MAF is attached right after your airbox. Check and make sure the harness is properly connected. The TPS is on the driver's side throttle body. Make sure that is also properly connected.Those are some easy checks you can do.
J30 idle problem?
hi;
thanx for all the info. what i find odd is the absolute regular pattern of this problem. it doesn't occur when i start the car cold (like in the morning), but as soon as it cycles down to "regular" operation the problem begins. occurs regardless of whether i've been driving the car for three minutes or three hours. always the same ... engine speed cycles from about 650 on Tach to about 950 every 40 - 45 seconds if the car is in Park, Drive or Neutral. doesn't seem to affect regular driving. i'm not capable of diagnosing or fixing this myself, but i have a friend who is quite knowledgeable with respect to cars, and if i have to take it in for service, i would like to be armed with some information in order to make sure i don't get overcharged. appreciate the help. cheers.
thanx for all the info. what i find odd is the absolute regular pattern of this problem. it doesn't occur when i start the car cold (like in the morning), but as soon as it cycles down to "regular" operation the problem begins. occurs regardless of whether i've been driving the car for three minutes or three hours. always the same ... engine speed cycles from about 650 on Tach to about 950 every 40 - 45 seconds if the car is in Park, Drive or Neutral. doesn't seem to affect regular driving. i'm not capable of diagnosing or fixing this myself, but i have a friend who is quite knowledgeable with respect to cars, and if i have to take it in for service, i would like to be armed with some information in order to make sure i don't get overcharged. appreciate the help. cheers.
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Mayhem_J30
- Posts: 2643
- Joined: Tue Apr 30, 2002 2:00 am
- Car: Ummm...My Car
- Location: Louisville, KY
J30 Idle Problem?
hello;
thanx for all the info. i hoping to convince my buddy to come over this weekend and take a looksee at the car. he is much more knowledgeable than i am with respect to these sort of things. when i bought the car and took it in for an independent assessment the garage told me that the car was in primo shape mechanically ... he did a compression test and it came out at what he called "spot on" at 165 for each cylinder. i was told that the compression test was a general indication of overall engine "health". what exactly does a compression test show and tell me? i also had a transmission service done after i bought the car with a pan drop and changed to synthetic. he indicated that the transmission and underbody looked virtually brand new. i took the mechanic some posts from here so he knew exactly what i wanted. could that have any bearing on this rpm problem. anyway, any advice is appreciated.
thanx for all the info. i hoping to convince my buddy to come over this weekend and take a looksee at the car. he is much more knowledgeable than i am with respect to these sort of things. when i bought the car and took it in for an independent assessment the garage told me that the car was in primo shape mechanically ... he did a compression test and it came out at what he called "spot on" at 165 for each cylinder. i was told that the compression test was a general indication of overall engine "health". what exactly does a compression test show and tell me? i also had a transmission service done after i bought the car with a pan drop and changed to synthetic. he indicated that the transmission and underbody looked virtually brand new. i took the mechanic some posts from here so he knew exactly what i wanted. could that have any bearing on this rpm problem. anyway, any advice is appreciated.
reply to myself
tried an experiment. when i put the heater unit in "econ" the problem disappears and the car idles at about 800 rpm. what's up with that? does that mean my A/C is screwed up. any advice is appreciated. thanx.
Re: reply to myself
The same thing is happening in my J as well but intermittantly. I hope your buudy comes up with an answer.gdude45 wrote:tried an experiment. when i put the heater unit in "econ" the problem disappears and the car idles at about 800 rpm. what's up with that? does that mean my A/C is screwed up. any advice is appreciated. thanx.
well i dont have my J30 here to check things out for you, but surges of that magnitude could be caused by the fan turning on or off or by the AC compressor turning off and on.
now that i read your most recent post about ECON mode...>> ECON mode means you are not using the AC compressor.
which in turn means your surging problem is simply caused by the AC compressor turning on/off hyperactively.
i dont know if maybe the AC pulley clutch is sticking or something, or the belt is too tight, or your controller unit is messed up. i cant tell because im not there. first, make sure your belts are at the right tension.
good news is that its not your engine at all!
listen to this:its winter now in most parts of this country
now that i read your most recent post about ECON mode...>> ECON mode means you are not using the AC compressor.
which in turn means your surging problem is simply caused by the AC compressor turning on/off hyperactively.
i dont know if maybe the AC pulley clutch is sticking or something, or the belt is too tight, or your controller unit is messed up. i cant tell because im not there. first, make sure your belts are at the right tension.
good news is that its not your engine at all!
listen to this:its winter now in most parts of this country
<oops new post>
so, you should be in ECON mode during the winter anyway, unless you are having trouble with windows fogging up.
side note: i have had small surges in my J30 now that i think of it, probably related to the same thing.
i do not use any climate control 95% of the time though, so it is not an issue for me.
ok this post is getting long
my verdict>>
the engine is fine. the A/C system is fine. there might be a small problem in the tension on the belt, or a worn out AC clutch. thats all.
so, you should be in ECON mode during the winter anyway, unless you are having trouble with windows fogging up.
side note: i have had small surges in my J30 now that i think of it, probably related to the same thing.
i do not use any climate control 95% of the time though, so it is not an issue for me.
ok this post is getting long
my verdict>>
the engine is fine. the A/C system is fine. there might be a small problem in the tension on the belt, or a worn out AC clutch. thats all.
J30 Idle
hello;
thanx. i do believe it is the compressor cycling on and off. i guess when it comes on the engine increases it's rpm. i drove a RX-7 for the past 18 years (original owner) bought when i was going to university and it hadn't had A/C working for the last 10 so all these new-fangled devices are a mystery to me ... but i'm learning with the help of this board.
in my neck of the woods you don't see many infiniti's around. J30's are as scarce as hen's teeth. i've never seen another one. see the odd Q, and a few I30/35. i see more G35's than anything now, so i guess infiniti finally has a winner (sales).
anyway, i want to get a tune-up and coolant flush when some money becomes available later this spring. even though the car only has 45,000 miles on it, it is 10 years old and probably hasn't had much done to it. any best practices. what should i change for sure, and what is ok to just have checked. any advice mucho appreciated.
thanx. i do believe it is the compressor cycling on and off. i guess when it comes on the engine increases it's rpm. i drove a RX-7 for the past 18 years (original owner) bought when i was going to university and it hadn't had A/C working for the last 10 so all these new-fangled devices are a mystery to me ... but i'm learning with the help of this board.
in my neck of the woods you don't see many infiniti's around. J30's are as scarce as hen's teeth. i've never seen another one. see the odd Q, and a few I30/35. i see more G35's than anything now, so i guess infiniti finally has a winner (sales).
anyway, i want to get a tune-up and coolant flush when some money becomes available later this spring. even though the car only has 45,000 miles on it, it is 10 years old and probably hasn't had much done to it. any best practices. what should i change for sure, and what is ok to just have checked. any advice mucho appreciated.
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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
in my neck of the woods
gdude45,
Why don't you idnetify your "neck" in your profile? It will help when you post to the mechanics forum especially.
Why don't you idnetify your "neck" in your profile? It will help when you post to the mechanics forum especially.
theres tons of J30s where ever i look here. for me, i saw no J30s around until i bought mine...and its not just because i didnt notice them, ive always noticed them. I saw one one the road only ONCE before i bought mine.
in any case:yah you should do the coolant, get some good oil in there, do a transmission flush, and make sure all the brake components are all in spec.
if you do the "tune up," remember not to use bosch platinum plugs. they are great plugs, but they do bad things for the VG series of engines. go with the OEM nissan.infiniti parts, i believe they are NGK.
in any case:yah you should do the coolant, get some good oil in there, do a transmission flush, and make sure all the brake components are all in spec.
if you do the "tune up," remember not to use bosch platinum plugs. they are great plugs, but they do bad things for the VG series of engines. go with the OEM nissan.infiniti parts, i believe they are NGK.