Idle problems and 1st gear

corbanbrook · Post by **corbanbrook** » January 22nd, 2006, 10:04 am

Just recently bought a 4cyl 92 MX-3 to drive around in the winter. Took it to the mechanic and had him certify it. He did about $1500 in various repairs.

Drove it home (just a few blocks away) and didnt notice any problems.

The next morning I start it, idle is fine at 1000RPMs but after driving for 5 mins and it heats up the RPMs start going up and down when im stopped. Idleing now at around 700RPM and then dipping to 100RPM every 5 seconds then back up to 700RPM. It has begun to get worse and is stalling out when I try to put it into first. Unless i rev the egine to 3000-4000 RPMs before showly engaging the clutch it has been stalling frequently.

Now the 2nd problem is that once it stalls the engine floods (i beleive) and i have to wait on the side of the road for some time before it will start again.

Friday night on the way home from work it stalled twice at stops and it wouldnt start again.

This starter problem has seemed to develop just this week as it use to start easily every time... Im not sure if its the cold winter taking effect or not... the week before was rather warm compared to this one.

Thank you for any help. I am a first time poster. These forums already look like a great resource.

93_mx3_gs · Post by **93_mx3_gs** » January 22nd, 2006, 1:19 pm

The car is heating up ? As in over heating ?

I noticed when I purchased mine I just so happen to have had purchased it on a day where it was only 20 F outside and the people let it in their back yard for nearly 4 years and they never put anti freeze in it because they brought it from CALI and the same week they were here, disty kicked the bucket so I repaired the car enough to drive it hm but since it never had anti freeze in it, the lines and all coolant channels were frozen..sucked..Something else you may want to check out is your thermostat. Easy fix, about ten minutes in total work and effort.

About the revving, it could be related to your coolant system when it starts to get hot or it could be Vacuum related. If your car needed 1,500 in repairs when you got it, it would not surprise me if there were some rotten hoses that are leaking vacuum stability. These are generally easy to detect with a can of TB cleaner or Starting Fluid in small amount, just spray them around areas such as vacuum connections, TB housing, Intake tube, Intake manifold base. If you engine revs in any of the areas you sprayed, act accordingly to that area. replace hoses, new manifold gasket, new intake tube , new tb gasket etc.

Good luck.

corbanbrook · Post by **corbanbrook** » January 22nd, 2006, 11:45 pm

Thank you 93_mx3_gs,

sound advice, I will look into it.

Before when i said heating up i really just meant after the car had a chance to warm up.. still within reasonable limits

First starting the car in the morning everything is fine, but after i drive it a few blocks the idle starts to dip almost to the point of stalling.. but hasnt yet.

Someone else recommended i try some fuel injector cleaner dont know if that will do any good or not.. sounds to me like a more complex problem.

93_mx3_gs · Post by **93_mx3_gs** » January 23rd, 2006, 1:27 am

Idle problems are usually a vacuum issue 90% of the time. If you find no vacuum issues, i'd hit up the coolant system it may be sending the wrong readings causing ECu confusion. In one of my earlier posts, I had to take my car in to emission it and when they ran it on the dyno roller, the temp needle was fine but they said it started to idle dive before re-running the tests and I was like wtf ? Anywho, steam started pouring out of my car and the needle never went above normal but when I was driving on the road around with my temp late, the cold air offered sufficent cooling and anywho, it ended up being a locked thermostat.

Good luck man =)

ryanlindenberg · Post by **ryanlindenberg** » January 25th, 2006, 9:31 pm

yea my car overheated on the dyno too because of a faulty temp guage...i have now installed an autometer temp guage so that problem is fixed. mine wouldn't go past the middle point either.

what did the mechanic fix? maybe you just need to reset your idle because of something he did.

Black4CylMX3 · Post by **Black4CylMX3** » January 25th, 2006, 10:08 pm

Could someone please explain how to reset your ECU? I've done a little searching but haven't found anything.

corbanbrook · Post by **corbanbrook** » January 26th, 2006, 10:52 am

Well.. this was my friends car, and i drove in it the week before i bought it and it was fine. I know he played with a bunch of stuff to get it to pass the Emissions test. it failed the test 2wice and passed on the 3rd attempt. He might have played around with the idle for this. I am seeing the mechanic on friday so hopefully its a quick fix.

Temp guage never seems to go past half. so i dont know if that is good or not. Problems with the idle only seem to occur when it reaches the 1/2 way point on the temp gauge, but as its warming up to that point it works perfectly. Go figure.

Tunes67 · Post by **Tunes67** » January 26th, 2006, 1:06 pm

Likely just a crack(s) in the flex hose from the airbox to the throttle body. However.. it could also be your IAC valve sticking or your coolant temp sensor malfunctioning. Check the flex hose first, then replace your coolant temp sensor and if those 2 things dont take care of the problem.. you may need to remove your throttle body and clean it up and readjust everything. I did a write up a while back on how to do this to your throttle body if you need to do so, with pics and complete instructions.. its a 2 part post.. part 2 got filed away in the 4cyl FAQ area.. part 1 is floating around and you will have to do a search for it. Hope this helps.

Tunes67

Tunes67 · Post by **Tunes67** » January 26th, 2006, 6:27 pm

Here is Part 1.. took a bit of searching to find it so I figured I would post it for you. Part 2 is in the 4cyl FAQ section.. I will ask the admins if Part 1 can be added to the FAQ section as well. Cheers

http://www.mx-3.com/phpbb2/viewtopic.ph ... ean+adjust

Tunes67

corbanbrook · Post by **corbanbrook** » January 27th, 2006, 2:46 pm

thanks Tunes67,

It is at the mech right now having the throttle cleaned.

I will let you know how that goes.

corbanbrook · Post by **corbanbrook** » January 27th, 2006, 3:49 pm

http://www.mx-3.com/phpbb2/viewtopic.ph ... c&&start=0

found this thread today, the problems he is experiencing are EXACTLY what im getting.

corbanbrook · Post by **corbanbrook** » February 3rd, 2006, 11:02 am

Last week i took the car to the mechanic to have the throttle body cleaned.

I think he must have also adjusted the indle rpm.

It still really bounces around a lot but this time its at 1000RPM-2000 instead of 700RPPM-100RPM so it felt a little safter driving and drove it until today without the engine quiting out.

Today it was above freezing, very mild and raining, drove out of my parking garage and made it a few kilometres down the road when i hit a red light.

put it in first and started to tried to drive off and it just quite imediately while melding the clutch. And then guess what... engine flooded or something and wont start. Starter operates but engine wont turn over.

Push the car off to the side of the road and wait 20 mins. Start it and able to get it to work. But the entire way there the idle was dropping again to 100 RPM and i really had to gas it when going into first.

At this point im guessing the engine is miss firing really bad when its damp.. so im going to get some WD40 and spray it around the spark plugs, distributer and wires. and see if i can get it to my mechanic to have him check that out.

Any other ideas?

sharpie · Post by **sharpie** » March 2nd, 2006, 11:56 am

This seems to be more common than I thought. I have a 94 MX-3 GS and about 90% of the time when at idle, it bounces from 100 to 500 rpm. Really embarrasing when at a stop light 'cuz everything thinks im getting ready to race them!

I lurked through this thread and will change the filter and check the hoses etc...

I hope this will clear it up, I'm heading on a long road trip soon and I sure don't need my car quitting on me in the middle of New Jersey!

corbanbrook · Post by **corbanbrook** » March 2nd, 2006, 12:13 pm

sharpie: is your Check Engine light coming on?