[alexunderwoodtr720]

i have a 1990 yota with a 3.0 v6. i have been having a issue the past couple of months. it feels like i have a misfire at idle and on acceleration. and sometimes it misses when im jsut crusing at high way speeds. it is driving me crazy. i have no power and my fuel econ has gone down to about 13 in the city i used to get about 18. any ideas? please help. it atarted happenign a little after i did a tune up (cap, rotor, plugs, wires, fuel filter, recharged ait filter)

 

[V62WDLongbed]

Although rare I've heard of some spark plug wires being defective right out of the box. Same I suppose could be true of spark plugs. I would suggest you take your timing light and check each spark plug wire to see which one or ones are causing the misfire.

Also double check to see that you didn't mix up the firing order when you changed your spark plug wires.

 

[toytruck89]

if you have access, a scope will give you all the information you need about your ignition system (plugs, wires, cap, rotor)

But I am more than willing to bet that you clogged up your little MAF element and you are getting a rich misfire. Which would explain the poor mileage. Take your MAF out, pick up some "contact cleaner" at wal mart and give it half the can and make sure your air filter is dry before you put it back on.
Let me know if that's the problem :thumbup:

 

[alexunderwoodtr720]

Although rare I've heard of some spark plug wires being defective right out of the box. Same I suppose could be true of spark plugs. I would suggest you take your timing light and check each spark plug wire to see which one or ones are causing the misfire.

Also double check to see that you didn't mix up the firing order when you changed your spark plug wires.

i have double checked my plug wires. when i pull one off the miss just gets worse

 

[alexunderwoodtr720]

if you have access, a scope will give you all the information you need about your ignition system (plugs, wires, cap, rotor)

But I am more than willing to bet that you clogged up your little MAF element and you are getting a rich misfire. Which would explain the poor mileage. Take your MAF out, pick up some "contact cleaner" at wal mart and give it half the can and make sure your air filter is dry before you put it back on.
Let me know if that's the problem :thumbup:

where would my MAF element be located? i know that is kinda dumb but i really know nothing much about this engine.

 

[Sidney]

where would my MAF element be located? i know that is kinda dumb but i really know nothing much about this engine.

I am not familiar with the 3VZE engine used in about 65% or so of the 1988-95 Toyota 4-Runners/pickups but I assume the AFM (Air flow meter as Toyota calls it,Honda calls it MAF sensor) is located above the air filter in the air filter housing.

Buy a can of throttle body cleaner and use it on the AFM housing and I suggest using it on your throttle body as well.

Lots of city miles combined with low octane fuel & no Techtron fuel additive (cleaner) creates excessive throttle body carbon build up (gunk) so throttle body must be cleaned.

To clean the throttle body remove the air intake hose and examine the intake and throttle body for excessive carbon build up if found then buy a can of throttle body cleaner labeled "safe on oxygen sensors, TPS's and catalytic converters" do not use carb cleaner make sure your engine is fully warmed up prior to using as when the throttle body is hot it dissolves the carbon easily and quickly.

The labels usually specify to park the vehicle at ground level (0 degrees, no inclination) and have the engine running but I disagree I instead park the vehicle on a hill facing down and shut the engine off and hold a rag below the lip of the throttle body and poor the stuff and use a tooth brush. You can also use "Sea Foam" the best engine cleaner:

http://www.seafoamsales.com

available in Canada through UAP/NAPA Auto Parts Stores.

:smokin:

Sidney® ™
Repairs TV's,VCR's,home/car audio out of my apartment
E-mail:sidneybek(at)yahoo.com
Dartmouth,Nova Scotia
Canada

 

[rivethed]

I also had a random miss, in my three vee-zee. I lived with it it for a while, tried new cap/rotor, wires, plugs, replacing vacuum lines, egr. For me, and I may be the exception, but when I replaced the distributor, it all went a way. Just another possibility.

 

[ohgood]

I also had a random miss, in my three vee-zee. I lived with it it for a while, tried new cap/rotor, wires, plugs, replacing vacuum lines, egr. For me, and I may be the exception, but when I replaced the distributor, it all went a way. Just another possibility.

Did you replace the CAP or the DISTRIBUTOR ? Just clarifying.

 

[rivethed]

I replace the distributor itself. :thumbup: Used the same cap and rotor as were on the unit that caused my persistent random misfire, I can only ponder what in the old unit was causing the problem.

 

[yotadrosos]

???

so did anyone figure out what this problum is ?

 

[ryanschillinger]

Mine ended up being the "EGR Vacuum Controller" or vacuum modulator, or egr vacuum switch (why so many names??). Its a little round thing with 3 vacuum hoses connected to the top part, and one on the bottom going directly to the EGR. It controls vacuum going to egr, and it was letting too much vacuum to mine, opening it too far, which caused a pretty bad hesitation on acceleration and cruising. Its just held in by a spring clip on the front of the engine. You can get one for around $50 from the internet (autopartswarehouse.com works) that is the original Toyota part...

 

[knj27]

^:lol: Auto parts warehouse has a couple smilies just so you know