98 4runner engine issues..

[91extcab]

I have a 91 pickup, with a 98 3.4 4runner engine. it idles great, doesnt back fire, no cel, nothing funky.. One problem though. at about 4K rpm it falls on its face as far as power. i replace wires and plugs, checked mass air flow, fuel filter, air filter and o2 sensors. It has a brand new exhaust, cat, muffler, piping etc.. Trying to figure out why this thing just pukes in high RPM's, right before redline.. I was thinking either fuel pump, plugged cat, something to do possibly with ignition. everyone trys telling me its normal, but i know its not. i drove my buddies 3.4 to compare and mine def has something wrong.. Any help is appreciated!! any ideas...

[91extcab]

no one? i am thinking that i it is a fuel delivery issue..

[jackrista]

Do You Run A K+n Filter, Spray Down The Mass Air Flow Sensor With The Right Cleaner And Try That. If You Think It Has A Plugged Cat, Do A Backpressure Test To See It Should Not Have More Than A 1.5lbs. Backpressure If It Does Then Something In The Exhaust Is Clogged. Muffler Or Cat. What Plugs Did You Put In?? Is It Throwing A Check Engine Light?? More Info Please.

[bigBs84]

I hade the same problem with my 99' taco and it was MAF related and I did the fuel filter at the same time all power was restored. It turns out that my K&N filter was getting to much oil on the MAF and it just took a good cleaning. It sounds like you tryed these issues but thats what the prob was w/ mine. Good luck I know how frustrating it can be to not have a passing gear.:thumbs:

[91extcab]

no check light.. Ill run that electrical cleaner in the maf and see what kind of results i get. Yes i have the K&N filter. Cat is brand new, header is brand new, all exhaust brand new. It feels like a fuel delivery issue. So i really think, its got something to do with that MAF sensor. Fuel filter is new too. I got the plugs from toyota. Not sure what model/etc. Thanks for the help guys!

[bigBs84]

cleaning the MAF sensor is not recomended by manufactor :no2: , is what the shop told me, but it worked on mine. If you have a chance mabee your buddy will let you swap with him to see if it runs any better before you go and buy a replacement if the cleaning does not work of course.

[bigBs84]

oh hey they do make some stuff that is called MAF sensor cleaner. I think they sell it at Kragen:thumbs:

[85solid]

I used to work for a toyota dealership as a mechanic and shop forman. And if I were you I would take the K&N and use it for target practice!! Nothing against K&N filetrs cause they do somewhat help out but I saw more problems caused from the oil on the maf than almost anything else!!!AGAIN K&NS WORK GREAT JUST NOT ON THOSE V6S!!!!!

[91extcab]

if thats the case, then what do you suggest? I dont actually have a 4runner or taco so its not really that easy to just run the stock air box assy... any other kits that are semi decent?

thanks

[85solid]

I have noticed here recently that some companys like AEM
and others are starting to produce a dry filter the same styles as you probably have I would check out different companys but you should be able to find a similar filter element but DRY!! Some of the adds I have seen have even comented on the MAF sensors getting oily from the filters and thats why they are starting to produce dry filters!!http://aem-no-oil-filter

I HOPE THIS HELPS OUT SOMEWHAT

[85solid]

Check this link out

http://truckworldtv.tenmagazines.com/products.asp?page=product&lpid=27654

[91extcab]

do the dry filters have the same protection? I would love to do a snorkel but dont even have the slightest clue now to go about it. Its a 91 truck with a 98 engine. I would have to do something totally custom..

[85solid]

I think you would run the same risks with the dry filter as with the oiled!!! A snorkel would be cool anyway, always good to keep the engine as far away from water as possible!! Or you cold try to find a stock air box and somehow incoperate in the engine compartment!!!!! By the way how much trouble was the swap??? the reason I ask is im almost finished with a chevy4.3v6 swap into my 85xtracab and its been fairly simple except for the money part!!!!!

[91extcab]

I think you would run the same risks with the dry filter as with the oiled!!! A snorkel would be cool anyway, always good to keep the engine as far away from water as possible!! Or you cold try to find a stock air box and somehow incoperate in the engine compartment!!!!! By the way how much trouble was the swap??? the reason I ask is im almost finished with a chevy4.3v6 swap into my 85xtracab and its been fairly simple except for the money part!!!!!


the 3.4 swap was most likely more difficult than yours. I bought a toyota and plan on keeping toyota through and through. No Chevy engines or Dana axles for me..

[jimbo88runner]

i cant wait to do my 3.4 swap into my 91. i also cant wait to get my 60s in!