Symptoms of a misfire / Possible causes? - 3000GT/Stealth International Message Center
3000GT/Stealth International 3000GT/Stealth International
 

Auto Insurance

» Featured Product
Wheel & Tire Center

Go Back   3000GT/Stealth International Message Center > Modifications and Technical Support > Engine - Non-Turbo

3SI.org is the premier Mitsubishi 3000GT Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 04-08-2004, 01:12 PM   #1 (permalink)
User
 
Join Date: Nov 2002
Location: Allentown PA
Drives: 96 3000GT SL
dsearfass is an unknown quantity at this point
Feedback Score: 0 reviews
Default Is this misfire? (no) .. What else could it be?

Not sure if what I'm experiencing is misfire .. but so far its my only guess. If anyone has any other suggestions feel free to share.

Car is a 96 SL auto with 150k.

Whats happening is occurring betwen 60-75 mph ..
In the past when traveling at 75, rpms would sit at 2700.
Now, I'll be going 75 .. rpms will sit at about 2700 for a couple seconds and then jump up to 3000. Sometimes they'll drop back down to 2700 but then jump right back up. I'll be traveling on flat road but the engine kind of acts as if im going uphill.

Any ideas of what could cause this?

Last edited by dsearfass; 04-15-2004 at 11:34 AM.
dsearfass is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 04-08-2004, 07:48 PM   #2 (permalink)
Hitokiri Battousai
 
Jeremy C's Avatar
 
Join Date: Jun 2002
Location: In the desert
Drives: A car that runs
Jeremy C is an unknown quantity at this point
Feedback Score: 48 reviews
Default Re: Symptoms of a misfire / Possible causes?

Sounds like you'er low on fluid. Check that and get back to us.

A misfire would sound like either a stumbling in the motor (when it doesn't fire at all) or a major POP sound (firing on the exhaust stroke causing detonation in the exhaust pipes).
Jeremy C is offline   Reply With Quote Quick reply to this message
Old 04-08-2004, 10:58 PM   #3 (permalink)
Forum Member
 
Join Date: Sep 2000
Location: St. Louis Area
Drives: 92 Stealth ES
hoppyumr is an unknown quantity at this point
Feedback Score: 2 reviews
Default Re: Symptoms of a misfire / Possible causes?

I agree.
__________________
Mark A. Hopkins, PE (MO, WA, OK, MT, IL)
*** Auto-manual swap ***
*** Free Do-It-Yourself Short-Shifter Mod ***
1992 Emerald Green Stealth ES
1999 Jeep Grand Cherokee Lim.
2003 Lexus ES300
2008 Acura TL-NAV
1999 Formula 280BR (bow rider)

2002 BSEE - University of Missouri Rolla
hoppyumr is offline   Reply With Quote Quick reply to this message
Old 04-09-2004, 08:13 AM   #4 (permalink)
User
 
Join Date: Nov 2002
Location: Allentown PA
Drives: 96 3000GT SL
dsearfass is an unknown quantity at this point
Feedback Score: 0 reviews
Default Re: Symptoms of a misfire / Possible causes?

Thanks for the replies.

Definitely not misfire then because there is no popping nor does the engine seem to mis a beat.

I checked the tranny fluid level and it looked ok. The tranny was hot and the fluid was near the top mark. The fluid in there has about 40-50k miles on it ... maybe time for a change? Any other suggestions?
dsearfass is offline   Reply With Quote Quick reply to this message
Old 04-14-2004, 10:20 PM   #5 (permalink)
Hitokiri Battousai
 
Jeremy C's Avatar
 
Join Date: Jun 2002
Location: In the desert
Drives: A car that runs
Jeremy C is an unknown quantity at this point
Feedback Score: 48 reviews
Default Re: Symptoms of a misfire / Possible causes?

Quote:
Originally Posted by dsearfass
Thanks for the replies.

Definitely not misfire then because there is no popping nor does the engine seem to mis a beat.

I checked the tranny fluid level and it looked ok. The tranny was hot and the fluid was near the top mark. The fluid in there has about 40-50k miles on it ... maybe time for a change? Any other suggestions?
You also checked it with the car running, right? A lot of people forget that you have to have the car idling to get a proper reading on the trans fluid on an ATX. What color is the fluid? It should be a vibrant red/pink. If there is any discoloration (mostly brown) then it is definately time to replace it.
Jeremy C is offline   Reply With Quote Quick reply to this message
Old 04-15-2004, 10:11 AM   #6 (permalink)
User
 
Join Date: Nov 2002
Location: Allentown PA
Drives: 96 3000GT SL
dsearfass is an unknown quantity at this point
Feedback Score: 0 reviews
Default Re: Symptoms of a misfire / Possible causes?

Quote:
Originally Posted by Jeremy C
You also checked it with the car running, right? A lot of people forget that you have to have the car idling to get a proper reading on the trans fluid on an ATX. What color is the fluid? It should be a vibrant red/pink. If there is any discoloration (mostly brown) then it is definately time to replace it.
Yes sir, checked it with the car running. And the color looked mostly pink. This is a strange problem because I have absolutely no problems with the transmission. I know changing the fluid is preventative maitenance but ever since my last episode with a tranny fluid change I'm hesitant to do it, especially if nothing seems to be wrong.

Here are some more ideas that have been floating around in my head .. see if these raise any flags.

I remember when I would drive on the highway and the car was still cold, the engine would run 75mph @ 3000rpms. After about 10 mins of driving on the highway the rpms would slowly creep down to about 2700 and remain there. Is there something in the engine/transmission that controls this .. maybe based on engine temp? Also, does anyone with a mtx experience this?

Lately I've noticed a sound coming from (i think) the driverside wheelwell. Sounds like a metal on metal grinding sound. Only happens when I'm going about 30-50 mph .. and it seems to happen mostly when I left off the gas. This sound definitely has a rythm to it.. makes a grind every other second and then goes away. Breaking does not affect it. Thought maybe it could be a bad wheel bearing so I jacked the car up and attempted to wiggle the front wheels .. no deal. They were solid. I'm not eliminating the wheel bearing .. but it could definitely be something else. Going to try to take a look at both wheel wells this weekend and see if anything is physically making contact with the rotors. Anything else to look for? I read a post where someone had this simliar problem and turned out to be a broken break pad... something as simple as that would be nice. Anyway, just wanted to mention the grinding sound in case it had something to do with problem #1.

What would I do on the weekends without a car to fix
dsearfass is offline   Reply With Quote Quick reply to this message
Old 04-16-2004, 10:04 AM   #7 (permalink)
Forum Member
 
Join Date: Dec 2000
Location: Olathe, KS
94-3kgtBase is an unknown quantity at this point
Feedback Score: 0 reviews
Default Re: Symptoms of a misfire / Possible causes?

how long has it been since your fuel filter, plugs, and wires were changed? might try checking them.
also both of my 3s's have done the starting out at a higher rpm and lowering it as it warms up. so i wouldnt worry about that.
the scraping sound might also just be your brake guard rubbing, if it is, just bend it back some so it doesnt rub.
jesse
__________________
94 Pearl Yellow Stealth RT
-- 17" Helo Nerve wheels with 245/50 kuhmo tires
-- Concept Audio IDM-777n 7" Motorized Screen In-Dash DVD Player
-- Concept Audio 6.5 components, 6x9's, and 752L amp to power the 6.5's
-- Concept Audio 250ML amp to power the HZ10-4 (when it finally gets here)
-- Tinted Windows

94 Green 3000GT Base
-- Bought 11/00 with 125k Sold 12/03 with 188k and still going
94-3kgtBase is offline   Reply With Quote Quick reply to this message
Old 04-16-2004, 12:16 PM   #8 (permalink)
Go get bent
 
LUSTFUL's Avatar
 
Join Date: May 2003
Location: Canton Ohio
Drives: Just a NA
LUSTFUL is an unknown quantity at this point
Feedback Score: 0 reviews
Default Re: Symptoms of a misfire / Possible causes?

umm the grinding noise does it do it just when turnig one way, or is it constant all the time??? sounds like wheel bearing issues to me. jack up the car and see if one of those front wheels wobbles back and forth a lot.. more than normal. that is usually indicitive of wheel bearing gone bad. could get lucky and just need some pads up front though... good luck to you
__________________
'93 Dodge Stealth ES: BPU and a bit more maybe



Quote:
Hey bois duz dis ebay chip work make mah whip teh fasterest?
LUSTFUL is offline   Reply With Quote Quick reply to this message
Old 04-16-2004, 12:32 PM   #9 (permalink)
User
 
Join Date: Nov 2002
Location: Allentown PA
Drives: 96 3000GT SL
dsearfass is an unknown quantity at this point
Feedback Score: 0 reviews
Default Re: Symptoms of a misfire / Possible causes?

Quote:
Originally Posted by LUSTFUL
umm the grinding noise does it do it just when turnig one way, or is it constant all the time??? sounds like wheel bearing issues to me. jack up the car and see if one of those front wheels wobbles back and forth a lot.. more than normal. that is usually indicitive of wheel bearing gone bad. could get lucky and just need some pads up front though... good luck to you
the noise is pretty much random as far as steering and breaking go .. there doesn't seem to be any relation between them. im going to replace the front pads this weekend, they are low anyway. hopefully that will have some effect. back ones need replacing also. are they any different than the fronts?

as far as the fuel filter goes .. it has been awhile, same with the injectors. they could probably use some cleaning. plugs and wires were done ~10,000 miles ago.. so they should be good.

i'll look into cleaning the fuel system.
thanks for the help fellas
have a good weekend
dsearfass is offline   Reply With Quote Quick reply to this message
Old 04-16-2004, 12:34 PM   #10 (permalink)
Try Me
 
Blk973KGTVR4's Avatar
 
Join Date: May 2003
Location: Pa
Drives: 99 Vette, 02 C32 AMG
Blk973KGTVR4 is an unknown quantity at this point
Feedback Score: 0 reviews
Default Re: Symptoms of a misfire / Possible causes?

Your exhaust note will change with a Misfire. Just listen to your exhaust.. Also a Power loss will occur.
__________________
1999 Triple Black Corvette Vert
364rwhp, 371rwtq
13.12@108.79mph - Cam Only
Vararam, Corsa Exhaust, Sleeper Cam, LS6 Intake

2002 Brilliant Silver Mercedes-Benz C32 AMG
Custom Blower Pulley, Custom 3" Borla Exhaust, Custom Heat Exchanger
321rwhp, 316rwtq
12.77@113.52mph
Blk973KGTVR4 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

  3000GT/Stealth International Message Center > Modifications and Technical Support > Engine - Non-Turbo

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the 3000GT/Stealth International Message Center forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Free email addresses do not work(yahoo, hotmail, gmail,...)
We are currently being blocked by AOL so any AOL based address may not work(aol.com, aim.com, netscape.net, cs.com)
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 03:35 AM.




Garage Plus vBulletin Plugins by Drive Thru Online, Inc.

Search Engine Optimization by vBSEO 3.3.2