DeckerT4R

I have searched and i found a post where the guy had the same problem (he did not have poor gas mileage just the studdering) however everyone said his problem was fuel starvation because of his supercharger. I dont have a S/C.
I have massive RPM studder when I go over half throttle from 1K rpm
to 2.5krpm, after that it smooths out. The rpms seem to bog down unless I let off on the throttle a slight bit. It feels like a really bad misfire. However i'm not getting a MIL. I have replaced the fuel filter, spark plugs, i've cleaned the MAF sensor and the throttle body.

Thanks for any ideas or suggestions.
Ben

T-town

I actually just took my 98 runner in today to a toyota tech for the same problem here in Bozeman. At first we thought it was the tranny because of the bad shudder under acceleration but it would stop and run fine over about 20 MPH or 2500RPM like yours. Apparently sometimes when you take your car in to get a tune up some shops will only replace half the spark plugs to save money and rip you off. when the older plugs wear out more you get a bad 'crossfire'. He replaced all the spark plugs and it runs perfect now! Hope this helps

DeckerT4R

I replaced the spark plugs myself. I wish it was that easy. However i do have a plug that likes to come loose that i have to tighten every once and a while. I dont think that is the source of my problem however because even right after tightening it down it does not make a difference. Thanks for the idea though.

stock87

Wild guess, but I'll throw it out there... checked your ground wires lately?

hopper

If you search for cylinder misfire you get more than a few people that have the same problem as you are describing. (me being one of them) This is just a guess but I think it may be a clogged/ faulty fuel injector. That’s what I think my problem is but I haven’t had time to buy an new injector. (have auto zone check your codes...sometimes the light wont go on but the computer stores that there is a code. Mine says cylinder #3 misfire so this next days I will try to see if that does it)

Elton

so you didint replace the plug wires hmm did it just start doing this ?

Quickdraw

I had similar problems recently. Come to find out the spark from one of my coil packs was going down the side of the spark plug, which wouldn't be read as a "misfire". Put silicone around base of spark plug to isolate the spark down the center and put spark plug boot lubricant in the boot. Since then its run fine.

DeckerT4R

I have since replaced the plug wires and got a new air filter.
I am now sitting at the Toyota Dealer.....(thinking this is gonna cost a fortune)

I guess well see......

I forgot to mention before that if i am going uphill and have it in 5th and keep it around 13-1500 RPMS it makes a thud that sounds like it is coming from the intake box.... i dunno. Thanks for all your help. I'll post when i know whats wrong.

Ben

X2and4X

What about that fuel filter. have you changed it? also clean your intake. clean your maf with some electrical contact cleaner. and seafoam the rest of the intake past that. that might help.

Mikestang

Loose vacuum hose? Loose intake plumbing?

DeckerT4R

I replaced the fuel filter about 2K miles ago and wiped out as best i could the throttle body and i checked the MAF but it looked really clean. Infact this morning i swaped MAF's with a friend out of his 97 runner, to test his in my car. It made no difference. Thanks

Elton

umm i think you should down shift to 4th to keep it from lugging

texsurfer

sounds like timing too. check your TPS.

fireteacher

not insulting you but did you gap them correctly? i changed mine and forgot to gap one and it ran like boo boo with eratic idling. CEL came on for misfire and i checked the plug and was like :pat:

all good now

scentdog

Hey all, don't know if this fits the same category but, my '07 Taco has a vibration from stop to cruising speed. That is, under demanding power once I stop asking for power it smooths out. Toyota TSB shows possible transmission mount weakening or pending failure. Changed out the transmission mount but still having the same issue.

DRCOFFEE

Crank sensor, cam sensor, clogged CAT, O2 sensor, broken spark plug, bad plug wires, igniter, what codes are you getting? Have scanned the ECM or just not seeing a check engine light?

scentdog

Thanks for getting back to me. New Plugs, new wires, no lights have not run scan as yet. but will have done today.