Misfire at idle w/normal temp

[87nasupra]

I've had my N/A for about 4 yrs now, and 6-8 months on my "JDM" engine. This is the first time i've ever had a misfire at idle while the engine is at normal operating temp. While it's in drive ,it does it more, neutral or park not as much, but it still does it. No engine codes, TPS adjusted to specs. and new plugs , wires , distributor cap---prevenative maint.---. New vacuum lines and no leaks says the vacuum gauge......but you know what - its still there.

Any ideas or suggestions ?

 

[cuel]

Fuel filter? If you haven't changed it, you need to anyway. Could be a dirty injector as well. I'd start with the fuel filter.

 

[Nick M]

When is the last time OEM tune up parts were used?

 

[87nasupra]

fuel filter was changed 2500 miles ago. OEM such as toyota? wires and plugs from toyota - the rest from advance.

 

[cuel]

How'd the old plugs look? Was there one or two that looked different from the rest?

 

[CRE]

checked the timing?

 

[87nasupra]

Plugs looked ok, it has always run rich.....as they all do. Mine were fine

Timing is set dead on 10 deg.

 

[cuel]

Have you run a fuel pressure test? Still kinda leaning toward an injector problem. Do you know which cylinder(s) its missing on? Or is it random?

 

[87nasupra]

Miss is random......can't tell what cyl. is missing though. It doesnt do it all the time, sometimes it doesnt do it at all. Pull injectors and swap them you think ?

 

[thechori]

i have sort of the same problem, exept mine misfire like every second... but it was after i replaced my plugs so i'm guessing it's that :\

 

[87nasupra]

This happened before the plugs and wire change, before any maintance was done....im still getting it after all the changes. Somebody told me it might be a HG leaking coolant in the cyl., but i dont think so.....no coolant loss, and all PSI between 148-150. Pretty damn nice numbers too.

 

[CRE]

A couple things I would check are the ISC, TPS and AFM. All when they're warm. When my AFM failed it was tempature specific, the only way I found it was but testing it after heating it with a hairdryer.

 

[supramacist]

CRE...,. you need to change you sn to macgyver or some sh%t.

You put out some really thought provoking posts and thats really all anyone here can ask for.

 

[87CandyBlueT]

I had this same problem with my gte for months and it got worse as time went on. Turned out to be a loose ground strap. (the one by where upper and lower intake meet.) Check that they are tight. Is your idle steady?

 

[cuel]

CRE: That makes sense. Now that you mention it, an AFM or TPS problem would have similar symptoms.
AFM: http://cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=94
TPS: http://cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&Page=101
Just in case you don't have 'em...

 

[mk3supraoz]

if is not the plugs i would check the AFM

 

[87nasupra]

Ok, worst case if i have to change out my AFM and TPS and it still happens then im gonna say screw it and not worry about it. But now its acting like it doesn't wanna go anywhere till around 3k RPM....then it starts pulling hard and when its up to temp. it acts fine just has the miss. I can't figure out why its doing this to me.

 

[CRE]

You might also want to take a look at the cold start injector, check if it's leaking.

 

[87nasupra]

Well, im writing down everything that i can think of as well as what you guys say . Friday after i get up from a good night of partying i am gonna take my car to work and start with all the stuff that could cause it and go from there.

Guess i'll see what i can find.

 

[87nasupra]

Well, i checked while i was at work earlier....i got a code 14 sitting in there. Whats the best place to start @ ? I checked wiring and they dont look to be broken of pinched. I'll have to check the specs. on the ignitor and coil and see what they say.