What is left to check?? I'm at my witts end

transam350 · 7-17-08, 18:28

Hey everyone I've been messing with this problem for a year now and I can not get it figured out. The car is an 89 mazda mx6 gt atx. Here are the symptoms, shakes at idle in drive around 700rpm, 90% of the vibration goes away when I put the car in neutral. If I rev the car up about 100 rpm it helps the vibration go away also. Could be why its better in neutral. Tried adjusting the idle scew with the test connector grounded. I could lower the idle but could not raise it past the 700rpm. Another problem related or not is that it hesitates bad the first time I hit the acceleration after its been shut off. Doesnt matter how long its been shut off it does it only once and feels like the car is running out of gas for a second or two then its back to normal and accelerates fine.
Heres what I have replaced: spark plugs, wires, dist cap rotor, fuel filter, o2, air filter, two side motor mounts, timing belts.
Heres what I have checked: timing, egr, IAC, the other two motor mounts, vaccum lines.
I have read tons of previous forums about people with the same shaking at idle problem but no one really seems to answer it. O yeah the shaking has been going on for a good couple years, while the acceleration problem started a few months ago. Sorry this is so long someone please help, as they will deserve a LOT of KARMA.
Thanks

**megalomaniac32x** · 7-17-08, 18:50

idle switch, carbon in the throttle body, batt connections(clean if corroision is on them), does it matter if it is in power or econ for the trans. does it change with the ac on or off?, throttle cable and kickdown cable adjustment, air intake hose for leaks.

transam350 · 7-17-08, 19:41

the battery connections are good, new battery, econ or power mode does not matter, and if I turn the AC on it bumps the idle up maybe 50-100 rpm and the vibration lessens to an acceptable amount. Similar to if i put it in neutral.

**ls six** · 7-17-08, 19:59

Check the resistance for each injector. The specs should be somewhere in the 1G section.

Has the fuel filter been changed recently? It's worth changing if it hasnt.

Check plugs for correct gap color (light brown/grey) and minimal wear. Check the legnth of each plug wire for internal breaks resistance and signs of arcing through the insulator.

Theres not much you can do with the coil but go ahead and check the resistance there too.

Check the motor/trans mounts.

**Rizzo90** · 7-17-08, 20:53

My car did this to me for months & drove me completely insane, same story, checked & RE-checked everything. I can't tell you how many times I reomved all of my intercooler piping thinking it HAS to be a boost leak wouldn't throw a code either. I wouldn't recommend doing what I did, cuz I just finally snapped one day & kept hittin the damn gas pedal & ran the holy livin donkey-spank out of the car & forced it to throw a code. it ended up being a bad crank position sensor which is in the disty ( thanks mazdameister for savin my ass

) apparantly this is an item that can be bad enough to make one need the services of a shrink before it's "bad enuff" to throw a code. Ask a buddy if he has a spare disty & run it once.....might help , might not. Hope it does

transam350 · 7-17-08, 21:12

spark plugs and wires, and fuel filter were changed to no avail. The crank position sensor could be a problem havent replaced that. what symptoms were you having. rough idle or stall on acceleration. The fact that the acceleration stall only happens once until after the car has been shut off makes me think its something electronic. The shaky idle seems like a motor mount because the car does have a hard first to second shift but from what i can tell the two mounts that i havent replaced look good, atleast not wiped out like would be needed to cause my problems.

**maffatato15** · 7-17-08, 21:26

is there any way you can get a video of the car at idle? I know the mx6 auto trannys always had a rough idle. I had one for 4 years and it never idled "smooth". But it did idle somewhat smooth in neutral.

**LARKEN** · 7-17-08, 23:35

Sounds like a vacuum line is off.
While idling if you pull one sparkplug wire off at a time, do they all make the same difference ?

transam350 · 7-18-08, 11:43

i dont have video recorder, but i can tell you that when it starts shaking its too much. No way anyone would buy this car new if it did this from the factory. id guess the oil dipstick vibrates about 1/2 to each side. its dang noticable in the steering wheel and mirrors, plus the hood vibrates everyonce in awhile with it. ill try the spark plug removal one at a time after i get off work tonight.

**maffatato15** · 7-18-08, 12:45

well i know the steering wheel vibrates in my lx and the mirror does too......idk about the hood

**Rizzo90** · 7-18-08, 19:28

you don't happen to have the tube that looks like a vac line from the egr hooked up to vacuum do you???

**ugly mx6 guy** · 7-18-08, 21:37

87 626 I had vibrated just like yours and would stop when you put it neutral. It did turn out to be a trans mount and also the front motor mount.

**automan** · 7-19-08, 23:41

There is a service bulletin that addresses a rough idle in auto tranny MXs. It recommends a few things like better-isolating the hood, raising the idle, and installing either new motor/tranny mounts or some other vibration isolation part. My GT has always had somewhat excesive vibration at idle, but according to the dealer techs, this was normal when the car was new. The gen 1 Integras were not much better, as I recall.

endymion · 7-20-08, 3:09

any luck? it sounds like we are having the same problems? and how hard is to put a new distributor in?

transam350 · 7-20-08, 21:52

so I'm thinking that this vibration may be a normal occurence in the cars with an atx, which really sucks because the vibration is very noticeable and likes to make other things rattle inside the car. If i was going to try and negate this vibration wouldnt a harder tranny mount make the vibration worse? Also i could just raise the idle a little and atleast make the vibration lessen but for some reason when i ground the test connector and turn the idle screw i can only lower the idle not raise it past 700 any ideas?

7-17-08, 18:28	#1 (permalink)
transam350 Join Date: May 2008 Location: Age: 23 iTrader: (0)	What is left to check?? I'm at my witts end Hey everyone I've been messing with this problem for a year now and I can not get it figured out. The car is an 89 mazda mx6 gt atx. Here are the symptoms, shakes at idle in drive around 700rpm, 90% of the vibration goes away when I put the car in neutral. If I rev the car up about 100 rpm it helps the vibration go away also. Could be why its better in neutral. Tried adjusting the idle scew with the test connector grounded. I could lower the idle but could not raise it past the 700rpm. Another problem related or not is that it hesitates bad the first time I hit the acceleration after its been shut off. Doesnt matter how long its been shut off it does it only once and feels like the car is running out of gas for a second or two then its back to normal and accelerates fine. Heres what I have replaced: spark plugs, wires, dist cap rotor, fuel filter, o2, air filter, two side motor mounts, timing belts. Heres what I have checked: timing, egr, IAC, the other two motor mounts, vaccum lines. I have read tons of previous forums about people with the same shaking at idle problem but no one really seems to answer it. O yeah the shaking has been going on for a good couple years, while the acceleration problem started a few months ago. Sorry this is so long someone please help, as they will deserve a LOT of KARMA. Thanks

7-17-08, 18:50	#2 (permalink)
megalomaniac32x Non-Turbo 626 Join Date: Mar 2005 Location: Plano, TX, USA Age: 32 iTrader: (2)	idle switch, carbon in the throttle body, batt connections(clean if corroision is on them), does it matter if it is in power or econ for the trans. does it change with the ac on or off?, throttle cable and kickdown cable adjustment, air intake hose for leaks.
	91 626 DX, 89 F2T swapped, probinator chipped ecu, 2.5 inch exhaust and downpipe, zebel housing, 10 psi, mazdaspeed FSTB, blaster2 coil, pacesetter sts, rstb and lower tie bar, suby calipers, rear disc brakes, PGT rear swaybar, eibach springs, MSD 6A http://www.cardomain.com/ride/2146610 http://www.dfwmazdas.com

7-17-08, 19:59	#4 (permalink)
ls six Join Date: Oct 2006 Location: omaha, NE, USA iTrader: (1)	Check the resistance for each injector. The specs should be somewhere in the 1G section. Has the fuel filter been changed recently? It's worth changing if it hasnt. Check plugs for correct gap color (light brown/grey) and minimal wear. Check the legnth of each plug wire for internal breaks resistance and signs of arcing through the insulator. Theres not much you can do with the coil but go ahead and check the resistance there too. Check the motor/trans mounts.
	96 MX-6 full exhaust A/C delete spoiler delete probe wheels and a turbo in the worx. 01 626 brake's98 626 sway bar Altima rear sway bar links.http://www.cardomain.com/ride/2934576 90 pontiac transam. 350 TPI motor new 24# injectors. Rebuilt trans. lots to come.

7-17-08, 20:53	#5 (permalink)
Rizzo90 Join Date: Nov 2003 Location: just east of the "LOU", IL, USA iTrader: (4)	My car did this to me for months & drove me *completely insane, same story, checked & RE-checked everything. I can't tell you how many times I reomved all of my intercooler piping thinking it HAS to be a boost leak* wouldn't throw a code either. I wouldn't recommend doing what I did, cuz I just finally snapped one day & kept hittin the damn gas pedal & ran the holy livin donkey-spank out of the car & forced it to throw a code. it ended up being a bad crank position sensor which is in the disty ( thanks mazdameister for savin my ass) apparantly this is an item that can be bad enough to make one need the services of a shrink before it's "bad enuff" to throw a code. Ask a buddy if he has a spare disty & run it once.....might help , might not. Hope it does
	'90 pgt.....the usual mods...........ps....I don't ask questions prior to searching Founder of the home for the grammatically challenged.....few pics of my baby!!... http://s212.photobucket.com/albums/c...t=5513cba4.pbw

7-17-08, 21:26	#7 (permalink)
maffatato15 im back from BAN camp Join Date: Aug 2005 Location: endwell, NY, USA Age: 22 iTrader: (3)	is there any way you can get a video of the car at idle? I know the mx6 auto trannys always had a rough idle. I had one for 4 years and it never idled "smooth". But it did idle somewhat smooth in neutral.
	1991 lxt 1989 mx6 GT - Daily driver and project car Zombie chip, 2.5 inch turbo back exhaust, aluminum hard pipes, blitz BOV, 8.8 mm Accel 300+ ferro-spiral race wires, blaster 2 coil, intrax lowering springs, factory rear strut bar

7-17-08, 19:41	#3 (permalink)
transam350 Join Date: May 2008 Location: Age: 23 iTrader: (0)	the battery connections are good, new battery, econ or power mode does not matter, and if I turn the AC on it bumps the idle up maybe 50-100 rpm and the vibration lessens to an acceptable amount. Similar to if i put it in neutral.

7-17-08, 21:12	#6 (permalink)
transam350 Join Date: May 2008 Location: Age: 23 iTrader: (0)	spark plugs and wires, and fuel filter were changed to no avail. The crank position sensor could be a problem havent replaced that. what symptoms were you having. rough idle or stall on acceleration. The fact that the acceleration stall only happens once until after the car has been shut off makes me think its something electronic. The shaky idle seems like a motor mount because the car does have a hard first to second shift but from what i can tell the two mounts that i havent replaced look good, atleast not wiped out like would be needed to cause my problems.

7-17-08, 23:35	#8 (permalink)
LARKEN Join Date: Apr 2001 Location: Ottawa,canada, Canada iTrader: (1)	Sounds like a vacuum line is off. While idling if you pull one sparkplug wire off at a time, do they all make the same difference ?
	1990 2.2 Turbo mx6, stripped body ,CT26 Turbo,water-Air intercooler, Hi-flow intake and head, Bully clutch, Megasquirt. Also a 1993 MX6 2.0L and a 1994 Black MX6 V6 (RWD project) http://www.cardomain.com/ride/2449401/1

7-18-08, 11:43	#9 (permalink)
transam350 Join Date: May 2008 Location: Age: 23 iTrader: (0)	i dont have video recorder, but i can tell you that when it starts shaking its too much. No way anyone would buy this car new if it did this from the factory. id guess the oil dipstick vibrates about 1/2 to each side. its dang noticable in the steering wheel and mirrors, plus the hood vibrates everyonce in awhile with it. ill try the spark plug removal one at a time after i get off work tonight.

7-18-08, 12:45	#10 (permalink)
maffatato15 im back from BAN camp Join Date: Aug 2005 Location: endwell, NY, USA Age: 22 iTrader: (3)	well i know the steering wheel vibrates in my lx and the mirror does too......idk about the hood
	1991 lxt 1989 mx6 GT - Daily driver and project car Zombie chip, 2.5 inch turbo back exhaust, aluminum hard pipes, blitz BOV, 8.8 mm Accel 300+ ferro-spiral race wires, blaster 2 coil, intrax lowering springs, factory rear strut bar

7-18-08, 19:28	#11 (permalink)
Rizzo90 Join Date: Nov 2003 Location: just east of the "LOU", IL, USA iTrader: (4)	you don't happen to have the tube that looks like a vac line from the egr hooked up to vacuum do you???
	'90 pgt.....the usual mods...........ps....I don't ask questions prior to searching Founder of the home for the grammatically challenged.....few pics of my baby!!... http://s212.photobucket.com/albums/c...t=5513cba4.pbw

7-18-08, 21:37	#12 (permalink)
ugly mx6 guy Join Date: Jan 2007 Location: Knoxville, TN, USA Age: 44 iTrader: (1)	87 626 I had vibrated just like yours and would stop when you put it neutral. It did turn out to be a trans mount and also the front motor mount.

7-19-08, 23:41	#13 (permalink)
automan Join Date: Sep 2002 Location: San Diego iTrader: (0)	There is a service bulletin that addresses a rough idle in auto tranny MXs. It recommends a few things like better-isolating the hood, raising the idle, and installing either new motor/tranny mounts or some other vibration isolation part. My GT has always had somewhat excesive vibration at idle, but according to the dealer techs, this was normal when the car was new. The gen 1 Integras were not much better, as I recall.
	89 MX6GT 01 Corvette Z51 Coupe 06 Lexus RX400h

7-20-08, 3:09	#14 (permalink)
endymion Join Date: May 2008 Location: DH, AZ, USA Age: 18 iTrader: (0)	any luck? it sounds like we are having the same problems? and how hard is to put a new distributor in?
	'89 gt turbo - never ever running.

7-20-08, 21:52	#15 (permalink)
transam350 Join Date: May 2008 Location: Age: 23 iTrader: (0)	so I'm thinking that this vibration may be a normal occurence in the cars with an atx, which really sucks because the vibration is very noticeable and likes to make other things rattle inside the car. If i was going to try and negate this vibration wouldnt a harder tranny mount make the vibration worse? Also i could just raise the idle a little and atleast make the vibration lessen but for some reason when i ground the test connector and turn the idle screw i can only lower the idle not raise it past 700 any ideas?