Slight Miss

[JDMMA70]

Before anyone says search I did and notice everyone elses problem was different.

Here's mine.

I've had this slight miss before and after a friend and I replaced the CPS and timed the car. I replaced spark plug wires (NGK Plug Wires), NGK Coppers gapped to .031, New IC Hoses (Soon to be replaced with Hardpipes), and a new TPS set correctly. Now my slight miss is noticible from time to time, only happens when the car is idling (when im at a stop light for example) but when im driving the miss isn't even noticible. I checked the coils and they all checked out fine. Plug wires are new barely any miles on them. The timing was set to 10' so im not sure where else to look. All my vacuum lines are set and secure. Like I said it isn't noticible when im actually driving the car, I just figured it was time to solve the problem.

Any ideas?

Thanks
~JDMMA70

 

[ATL88Supra]

How bad is the miss ?

 

[JDMMA70]

You can feel it inside the car when its idling it will do it a few times, then it'll be gone from anywhere to 5-12-20 seconds and then come back again. Its not noticible to the point the exhaust starts popping, but its noticible to where the engine shakes.

 

[bountykilla0118]

how much vac in HG's while you idle?

 

[JDMMA70]

how much vac in HG's while you idle?

Im not sure I quite understand your question? HG's? For a second I thought you were refering to mmHg.

Please elaborate im sort of a n00b.

Thanks
~JDMMA70

 

[wardog]

Do you have an aftermarket Boost Guage? What he ment the vaccum that the aftermarket guage shows while Idling. A good vaccum is 18-22, Im here in houston were do you live. Im by 59 and 10.

 

[JDMMA70]

Do you have an aftermarket Boost Guage? What he ment the vaccum that the aftermarket guage shows while Idling. A good vaccum is 18-22, Im here in houston were do you live. Im by 59 and 10.

Oh, no I havent purchased and Aftermarket boost guage yet, I will soon however as soon as funds permit. Im by I-10 and Fry Road. Pretty much i live in Katy.

 

[wardog]

I have a SUNPRO Boost guage from autozone just $15 until i can get money for a PROSPORT set of guages. I migh head to Katy later on today to go visit some family ill let you know and we can hook up my guage to your cat to check the vaccum.

 

[JDMMA70]

I have a SUNPRO Boost guage from autozone just $15 until i can get money for a PROSPORT set of guages. I migh head to Katy later on today to go visit some family ill let you know and we can hook up my guage to your cat to check the vaccum.

Thatd be cool let me know i should be home all day, but yeah let me know ahead of time so that i am home.

 

[ATL88Supra]

is the overall preformence of the car effected ? mine has the shakes sometimes but alot of cars and trucks do that

if its not effecting on road preformence i wouled not really worry about it

i really need a soundbit of the motor runing

 

[bountykilla0118]

Naw he should worry about it b/c it means there is a problem. Don’t be the typical MKIII owner..... Meaning spend the less time, money and effort on maintenance but spend more money, time and effort in performance. Getting the car to run right should be 1st.

Its a simple thing but you just need spend a little time to figure it out....

 

[ATL88Supra]

i have a 3.5" straght from turbo back and when i have had the slightest missfire i always here it, are you sure its a misfire a sound bit of your motor would help me tell you whats wrong, but from the information provided im kinda like wtf ? sorry if i seem a bit noobish or even as killa said "Don’t be the typical MKIII owner" a vacume leak will not cause the motor to shake it woull cause RPM drops and wont idle,

so whay dont we start at square one

when was the last time the car ran "Smooth"

when was the last oil change?

when did you replace the air filter?

when did you check your AFM to make sure it was working within specs

basic stuff like this..

 

[JDMMA70]

i have a 3.5" straght from turbo back and when i have had the slightest missfire i always here it, are you sure its a misfire a sound bit of your motor would help me tell you whats wrong, but from the information provided im kinda like wtf ? sorry if i seem a bit noobish or even as killa said "Don’t be the typical MKIII owner" a vacume leak will not cause the motor to shake it woull cause RPM drops and wont idle,

so whay dont we start at square one

when was the last time the car ran "Smooth"

when was the last oil change?

when did you replace the air filter?

when did you check your AFM to make sure it was working within specs

basic stuff like this..

Alright Q&A always works best.

when was the last time the car ran "Smooth"
Cant recall it did this when my dad first picked up the car back in June '07

when was the last oil change?
I changed the oil a month after i had the car. I didnt drive it much between July '07 until March 24th 2008 when i officially started driving the car after getting the kinks worked out.

when did you replace the air filter?
Replaced the Air-Filter in December of '07

when did you check your AFM to make sure it was working within specs
Checked the AFM as per TSRM and even have a used/better AFM Honeycomb thing.

 

[billwert]

I'm having same problems you are. Was told to change brand of spark plugs. I still have the same problem. Thinking about going back to the type of spark plugs that came out of it when it was running good instead of NGK's. Good Luck.

 

[JDMMA70]

I'm having same problems you are. Was told to change brand of spark plugs. I still have the same problem. Thinking about going back to the type of spark plugs that came out of it when it was running good instead of NGK's. Good Luck.

I had Densos in mine originally but i never started it up only my dad did. I replaced them with NGK coppers when i did the oil change. Now i can say the cars miss wasnt THAT apparent until i changed the plugs as my densos were gapped to .041 i guess that was to match the ridiculous timing.

 

[bryanintexas]

Factory Denso's FTW

 

[twinturbozs]

check your timing. I had a miss when i was set at 10 degrees, but lowering it to 5 degrees minimize it.

 

[billwert]

I'll Check my timing. And if that don't fix anything I'm gonna put Denso's back in it and gap em to spec.

 

[JDMMA70]

check your timing. I had a miss when i was set at 10 degrees, but lowering it to 5 degrees minimize it.

Wouldn't lowering it 5' lower my idle to like 500rpms?

 

[ATL88Supra]

Wouldn't lowering it 5' lower my idle to like 500rpms?

correct, time it per tsrm, also, this my be a long shot, but test out your ignigher (wow miss speeled the shit out of that)

clean your injectors too, never know

as for more Q/A

how long as it been like this ? ( missing )

did the last owner have head work done to it ?