Correct RPM adjustments

Angel · Post by **Angel** » January 22nd, 2006, 1:06 am

Hi, I have 95 MX-3 , I seem to have a problem with my RPM , about a year ago I was having a problem that my car would suddenly "die" when idle, like stopping at a red light and weird bursts while driving, I went to the mechanic and he said he just adjusted the RPM's ..Now I am having the same problem so I went in again and had it adjusted , now it hasn't shut down again but now when I have the gear in Park the rpm is about 2,000, compared to the ~700 it usually was while in Park, when I shift to Drive the rpms drop to 1,000. Now also while driving ocasionally I get some weird RPM bursts like I used to have. Does ~2000 while in Park sound correct? And should I worry about the bursts and have it adjusted again?

Thanks in advanced,
Angel

den · Post by **den** » January 22nd, 2006, 2:21 am

2000 in park is too high. Its not just about adjusting, there could be something wrong with your car. Is your car properly tuned up? You might wanna post on V6 or 4cyl technical promblems page. You will get more help there.

Grants · Post by **Grants** » January 22nd, 2006, 4:55 am

Check your air intake for leaks after the MAF and before the TB. The accordian hose is prone to crack and allow unmetered air into the engine and cause this type of problem.

Good luck with it and welcome to the forum!

Angel · Post by **Angel** » January 22nd, 2006, 11:15 am

den wrote:2000 in park is too high. Its not just about adjusting, there could be something wrong with your car. Is your car properly tuned up? You might wanna post on V6 or 4cyl technical promblems page. You will get more help there.

I think it's properly tuned up, at least thats the assumption since I payed the mechanic for it. I'll post it in one of those forums you mentioned and see what comes up. Thanks!

Angel · Post by **Angel** » January 22nd, 2006, 11:17 am

Grants wrote:Check your air intake for leaks after the MAF and before the TB. The accordian hose is prone to crack and allow unmetered air into the engine and cause this type of problem.

Good luck with it and welcome to the forum!

I'll get another mechanic and tell him to do this (as I have no idea how), how expensive do you think is the fix if I have this problem?

Also would it be safe for me to drive around with the RPMs too high? Is it easy for me to adjust it myself?

den · Post by **den** » January 22nd, 2006, 12:57 pm

High RPM will suck gasoline like crazy. Temporarily thats ok. But try to fix it or get it fix ASAP. There's no point in adjusting the RPM if there is a leak or something is faulty in your car, you will still experience the same problem after a while.

You can easily do a visible check on the hose. You MAY also hear a whistling like noise that means air is rushing to a small crack or hole. You can also try spraying some WD40 around the hose while engine is running, if there is change in RPM then that means the hose has a crack and it sucked the wd40 in.

I dont really think this relates to your problem but you can also check the PCV valve (its like an L shape pipe on top of your valve cover that has a hose connected to it) While your engine is acting crazy try to fold the hose so no air can pass thru it. If the RPM drops while you're bloking the passing air that means your pcv valve could be faulty then you may want to replace that. You can get it for $12 or less.

You always check RPM problems first at the most basic which is vacuum leak.

I am no professional, I just wanna help a fellow MX3er out.

Angel · Post by **Angel** » January 22nd, 2006, 4:17 pm

I just checked how my RPMs were behaving and to be more precise this is how it goes:

In Park: ~1600 RPMs
In Drive (idle) : ~1,000 RPMs

I'm assuming this isn't normal, can somebody tell me what kind of behavior I should consider normal?

Angel · Post by **Angel** » January 22nd, 2006, 4:24 pm

den wrote:High RPM will suck gasoline like crazy. Temporarily thats ok. But try to fix it or get it fix ASAP. There's no point in adjusting the RPM if there is a leak or something is faulty in your car, you will still experience the same problem after a while.

You can easily do a visible check on the hose. You MAY also hear a whistling like noise that means air is rushing to a small crack or hole. You can also try spraying some WD40 around the hose while engine is running, if there is change in RPM then that means the hose has a crack and it sucked the wd40 in.

I dont really think this relates to your problem but you can also check the PCV valve (its like an L shape pipe on top of your valve cover that has a hose connected to it) While your engine is acting crazy try to fold the hose so no air can pass thru it. If the RPM drops while you're bloking the passing air that means your pcv valve could be faulty then you may want to replace that. You can get it for $12 or less.

You always check RPM problems first at the most basic which is vacuum leak.

I am no professional, I just wanna help a fellow MX3er out.

I appreciate your comments, I'll take it first thing in the morning and I'll just tell the guy that another mechanic adjusted my RPMs (becuase my car was shutting down while idle) and that they are too high now and tell him to not only adjust it but to check for air leaks and pcv valve.

Thanks you very much.

Angel · Post by **Angel** » January 22nd, 2006, 4:26 pm

Grants wrote:Check your air intake for leaks after the MAF and before the TB. The accordian hose is prone to crack and allow unmetered air into the engine and cause this type of problem.

Good luck with it and welcome to the forum!

Thanks for the reply and Pardon my ignorance but whats the MAF and TB?

den · Post by **den** » January 22nd, 2006, 7:16 pm

Look at your intake... (the black platic box where the filter is in)

there is a metal cyclinder between the hose and the intake. Thats the MAF. Acutually the correct term is VAF (Voulume air flow sensor).

Then follow the big fat hose all the way to the metal part. That metal part is the TB(throttle body)

To learn more stuff. You can use the online shop manual. go to http://www.mx-3.com
then on the left panel under technical info, you will see online shop manual. Its very helpful and informative.

If you wanna learn some definitions/functions about such parts go to. http://www.wikipedia.org

By the way is your car GS or RS? Whats your location? You might wanna edit your profile and add a signature like the one you see on the bottom of my every posts. It helps members to give you more specific answers.

Post by **Custommx3** » January 27th, 2006, 4:50 pm

Moved to 4cl tech/performance

Joey's mx · Post by **Joey's mx** » January 27th, 2006, 5:12 pm

I had a similar problem with my 5 speed and it was the tps sensor that wasnt set properly??

Angel · Post by **Angel** » January 27th, 2006, 7:07 pm

den wrote:Look at your intake... (the black platic box where the filter is in)

there is a metal cyclinder between the hose and the intake. Thats the MAF. Acutually the correct term is VAF (Voulume air flow sensor).

Then follow the big fat hose all the way to the metal part. That metal part is the TB(throttle body)

To learn more stuff. You can use the online shop manual. go to http://www.mx-3.com
then on the left panel under technical info, you will see online shop manual. Its very helpful and informative.

If you wanna learn some definitions/functions about such parts go to. http://www.wikipedia.org

By the way is your car GS or RS? Whats your location? You might wanna edit your profile and add a signature like the one you see on the bottom of my every posts. It helps members to give you more specific answers.

Thanks den ....How do I know if my car is an RS or a GS? I live in Puerto Rico and I'll do the signature thing. Thanks again.

Angel · Post by **Angel** » January 27th, 2006, 7:08 pm

Joey's mx wrote:I had a similar problem with my 5 speed and it was the tps sensor that wasnt set properly??

Mine is automatic, somebody else mentioned the sensor to me ..how much did it cost you to get it replaced?

Angel · Post by **Angel** » January 27th, 2006, 7:44 pm

well now besides having a high rpm reading while in park (~1600) , now when I'm driving and the car warms up and I hit the break to make a stop the rpms start to dive and then either shut down or jump back up and keeps doing this. I'm really starting to hate my car.