4digger

So this is my second Toyota. I bought it on Thursday for 1850. It's a '94 4wd pickup in fairly good condition and I couldn't figure out why he was selling for so low until this morning when I went and drove around for a little while and in first and second gear after 2000 RPMs if I let off the gas just slightly and then give it a little more gas there's kind of a delay between when the gas pedal is pushed in and when it finally takes off and when it does it stumbles a bit and then it doesn't do it again unless I let off the gas slightly to try and get it to go a constant speed. It does it in the higher gears also but not nearly as bad. So we went through and tested a bunch of the things that could've malfunctioned like the TPS and it looks like almost everything is brand new except for the O2 sensor which I will be testing tomorrow morning. But anyways I was wondering if where it's only happening after 2000 RPMs if it could possibly be the EGR valve since if I remember right the EGR kicks in and does most of it's work between 2000 and 3500 RPMs. So I've heard that with the EGR valve you can just take the vacuum lines off and plug them rather than buying a new one. Thanks for any help guys!

nitty34

4digger,

Have you figured this out yet?

I'm having a very similar problem with my 93 4Runner. 3VZE. I've also replaced TPS, O2, etc. and no luck. Tried posting here a couple of weeks ago but no response.

Have you gotten anywhere with this?

Thanks!

4digger

Plugging the lines to the EGR valve helped with my problem quite a bit, but having the EGR blocked off causes the check engine light to come on so unless I can find some way to the check engine light off for it I'll be getting a new EGR when I have the money. Have you replaced the fuel filter or just sensors? I've also heard that the fuel pump can cause this but I don't know that for sure.

MOPARYOTA

i have this problem too with my 93 pickup 3.0L. i have replaced the fuel pump and it still does this 2000 rpm intermittent stumble! I will look into the egr..maybe thats it!!

nitty34

Mopar,

Mine ended up being the TPS. When I replaced it I had not calibrated it properly. In order to check, just unplug the TPS (behind the throttle body) and go for a drive. Once my TPS was unplugged the problem went away 100%.

Driving without the TPS made my truck run a little heavy. Had a hard time shifting into OD mode so the RPMs sat around 3K when I was on the highway - so gas mileage went to crap. BUT it allowed me to drive without the stumbling for a few days until I had time to pull the TB off and adjust the TPS properly. Runs like a champ now.

InToxicOne

I had this issue for a while there on my turbo truck. I wound up replacing the TPS because it had a dead spot right around the cruising rpm. Also check for air leaks. You may notice that this problem of yours goes away at higher rpms when vacuum pressure is less. Best way Ive found is turn the truck on and let it warm up then go around and spray brake parts cleaner on just about every single part on the intake manifold. If the engine rpms ramp up or the engine sounds like it smooths out there's your leak. Also check your spark plugs and ignition system. Putting the engine under load IE accelerating from a lower rpm like 2000 or less can put strain on a weak spark plug or wire.