lesha30

Hey guys,

I have a 91 4Runner. V6 Auto, 2WD with 102K mile on it. Stock size tires. Just had the HG recall done a few months ago.
Well, my question is: When I hit the freeway, it's easy to get up to 60-65 mph, but after that it's possible to accelerate further ONLY when I go downhill.

Please, any suggestions are welcome.

Thanks alot!!!

AgRunner06

Does your motor hesitate or sputter?

After driving on the highway for a little bit, look under your truck and see if the cat is orange. It sounds like you could have a clogged cat.

That's the only thing I can think of.

mt_goat

What about if you manually drop it out of overdrive, how fast will it go then?

TRunner

Try the cool Power button. You know the ECT? Well, depress that button and you should notice some change.

How does your engine idol? Sometime when the HG is replaced, if they do not reseat the valves, it can cause it to run rather rough. I think I am in that boat right now.

CTB

New fuel filter?

lesha30

Thanks for your replies!!!
It idles good. Nothing unusual.
My cat is broken inside. I know this, cuz when I start it in the morning, there are noises coming out of there. The fuel filter has been changed about 10K miles ago together with the plugs, wires, etc.
I'll try the "magic" ect button tomorrow, but shouldn't the truck get up to 75-85 mph by itself without the "magic" button and pedal to the floor?

Tacoma Dude

I've heard countless things about how a gutted cat doesn't provide enough back pressure or flow or something like that. If it's broken inside could it be the same thing? I mean, would the difference be that noticeable?

tom4416

Gutted is different from broken up. Pieces of the cat can get stuck in the exhaust system, creating undue back pressure and making the vehicle run poorly. Gutted assumes all the pieces of the catalytic converter have been removed so it's just straight through. Depending upon which OBD someone is running (I or II), it may or may not have an impact on engine operation. In OBD I, running a "test" pipe in place of the cat neither adds nor detracts from the output. I believe with OBD II, the system detects the change in backpressure plus the change in emissions and may adjust accordingly and/or store a code.

marcbeeme

i have the exact same problem with my 91 4Runner. People behind me get ed off when i cant go over 70 in the fast lane up a hill unless i get some speed. i have 32's though. You should get a few engine upgrades like a k&n and maybe if its in your budget a jet chip. I just got a k&n today 27th and it is very noticably faster but i havent taken it on the highway yet ill see how it does.
hope this helps, Marc

ChickenLover

Is your parking brake on? Ha Ha. Just kidding. Something is definately wrong.
I keep my second gen in tip top condition. It cruises at 80+ mph on the highway with ease. I would recommend an all out tune up. Air filter, spark plugs (I prefer platinums), wires, cap and rotor, coil, fuel filter, and some synthetic oil. All of this can be done yourself easily. If that doesn't work. I would have a new cat put on (high flow). Hope you get her runnin' right!

lesha30

I already have a cold air intake, but it's the cheap one from Ebay ($9.99 with an adapter). Do you know if there is a difference between my filter and K&N???

lesha30

And what's a Jet Chip?

TRunner

How do you get to that #6 plug?

marcbeeme

truckperformance.com is where you can get a jet chip. But I dont think that is the solution now. The best thing to do is take it somewhere and do a compression check on it, and a diognosis. Are you using any oil? My car is screwed, after taking it on the highway for a few hundred more miles it got worse. I can only get 10 miles to the gallon and i have to hold it to the floor all the time just to go 70 down hills. I usually have to drop it to 4th and that still dosent help much. I have 50 lbs of compression on my 5th cylinder. You should have over 100 in all of them. I also did all that good stuff like fuel filter, cap, rotor, plugs, wires, At 155,000 miles it is time for mine to go ahead and get a new engine. One question, do you get really bad gas mileage?

midiwall

If you're thinking about a JET chip, you should really think about saving money (in the case of the SMT) and going with something programmable. Like the:

The SMT series from Perfect Power:
http://www.perfectpower.com/
https://www.yotatech.com/forums/show...&threadid=5130 (thread here)

Or the Split Second FTC as sold by URD:
http://www.urdusa.com/


The JET chip is, ummm, "overpriced" - WAY overpriced.

HondaTec521

Maybe your cam timing if off . If the problem started after they replaced the hg's,and it was fine before,it sounds like they bochted something.

hale

I just picked up my new 91 v6 5spd and I was running 70mph no problem! It was raining and the ground was wet already from previous rain so I didn't want to go any faster...but I was only at 3k rpms

Flamedx4

I had the same problem when I bought my '90 pickup. Downshifting only got me about 5 more mph. Crist my old 85 22RE at 170,000 miles would still do 90 easily (not that it felt saFe at that speed mind you!)
Don't overlook silly basics. All that was wrong with mine was the throttle cable. REALLY!! Stupid. One minute with 2 wrenches and Oh What a Feeling! (couldn't resist.) What tires do you have? Although with a 2wd I can't imagine you're running really big tires... Do fix that cat, and make sure nothing is clogging the pipes while you're at it. But I agree with HondaTech, if it was fine before the HG then make them make it right!

lesha30

I have 235/75/15s on. What was wrong with your throttle cable?

ChickenLover

Flamedx4 brings up a really good point. Pull your intake hose off your throttle body and have someone push the gas pedal all the way to the floor (with the engine off of course.... I guess it wouldn't run with the intake hose off anyway so nevermind) . Look inside your throttle body and see if the butterfly inside is opening all the way. With the throttle pressed all the way, stick your finger in there and see if you can open the butterfly any more. If so, you should tighten up the slack in your throttle cable so that it opens all the way. Your idle might go up a little after this adjustment, but that's ok. Mine idles at about 1100 rpm in neutral.