Roofmaster

Driving home from work today on the highway doon 65 I wanted to see how my throttle response would be at that speed so I leaned on the accelerator pretty heavy expecting a response.Insted it creeped up to 70 and that was all I got,so I thought hmmm thats strange so I floored it.Same response,nothing.Never had a problem before and it still has good pickup and respponds well at low speeds.A few days ago I had the Plenum off to replace theBVSV valve on the in take manifold by the firewall.I also replaced the Plenum to manifold gasket.Im 99.9 percent sure I reassembled it correctlu.Did a head gasket job couple of months ago and used my pics and video from that adventure to make sure I did.Does anyone know why I cant get any speedor throttle response above 70 mph yet plenty of power and response at lower speeds.No other symptoms

bone collector

what gears and tires you have on the truck? what transmission? in my 94 with a 3.0 i can stomp the gas at 70 mph in 5th gear and quickly get to 85 mph. im running 32 in tires with 4.56 gears

87yotaaa

dang i need a v6, with my 22r, 4.10s, and 31s, 70 is bout all she gone do, and tachin 3 grand, and lets not even talk about hills haha

MudHippy

You got that right!!!

When's the last time you replaced, or cleaned, the air filter? Or maybe you've got a dead squirrel stuck in the air filter box? Or maybe you're just morbidly obese and asking too much from her? I dunno...

Side-note: When I bought my truck(3VZ-E reg cab long bed 4WD) I had no problem getting it up to 85mph on the highway ride home with a little throttle to spare. That was with 35s, 4.10s, manual tranny, and headed into the wind.

bone collector

I love my 3.0

sechott

Make sure the intake and trittle body is clean, get at least a Haynes manual and a multimeter and start checking and adjusting. That is what it took for my 3vz to wake up.

Roofmaster

I changed the air filter and did a complete tune up when I did the head gaskets a couple of months back.Im not morbidly obese,175 lbs. 5'10".Mudhippy if youre avatar is any indication of how you look your a bit annorexic or taken one to many hits off your crack pipe and its no wonder your truck could jump from 70 to 85 with throttle to spare.ha ha.Anyway Im running stock tires with an automatic transmission.I respect your advice muddhippy,Ive seen quite a few of your resppnses on here.Some more valuable than others.Honored to have your two cents worth.And thanx everyone else for your advice.I remember my old 86 with 33 12.5 tires wouldnt even get to 65.I have a Haynes and factory manual I might look into the throttle body and tps to see if I can tweak it a bit.Maybe advance the timing?What do you think.

Roofmaster

I also love my 3.0 and my truck in general.sechott what did you adjust to wake up your 3.0

Roofmaster

Not sure about the gears,I swapped axles a few months back.The axle on here now is from my 86.I still have the 33 12.5 tire from my 86 also and just have to do some anti rubbing mods before I put them on.Also how much gas milage will I lose with those tires?And performance loss?Im in the process of making a functioning hood scoop to cool the engine compartment and more specifically the crossover pipe.Will post pics soon.

sechott

First I adjusted the throttle plate according to the Haynes specs. You should see a little pin hole on the top side looking in with a mirror and flashlight. The plate should be edge to edge with hole visible throttle closed. You might have to take the dash pot off then adjust it later. Then I adjusted the TPS I couldn't get some good readings so I replaced. After I Got that right started the engine RPMs went to almost 2000 soI set the idle screw on the throttle body to bring down cold idle to 11,1200. Then I disconnected the hose on the valve cover under the TB and spayed cleaner in their. This will clean out the air bypass. I adjusted the timing found mine liked 15 btdc. Motor warmed I adjusted the air bypass again to bring RPMs to 800+ .

This made a huge improvement but something was still not quite right, so I took the air cleaner apart found the flapper was sticky. Cleaned it with MAF spray, got it working free. Cleaned the intake routing too. Then I disconnected various vacuum hose to spray cleaner in them while idling. Reset the timing, now instead of dying off my engine give power all the way to 5000, I can accelerate 5th great on the interstate with AC on. Climb hills without downshifting, it's great.

sechott

I also checked O2 sensor pulled and cleaned it, checked ohms for the VAFM, my engine was running lean so I cut the silicon around the access plate and adjusted to 3 click richer. Hope it works for you.

sechott

Thought I would clarify that I left about 1mm between the throttle plate and pin hole. In the Haynes the drawing shows edge to edge but I didn't think it would be good moving out that far.

Roofmaster

First thing I'll do tomorrow when I wake up.Did you have to remove the plenum at all.I dont have a timing light (probably the only tool I dont have) is there a way to accurately adjust timing without one?I'll buy one if not.Also forgot to mention Im getting the O2 sensor code on CEL.

MudHippy

I like this guy already. Not so much for the adoration. Which is flattering of course. But mostly for the fact that he doesn't see everything I've said as being of high value. Which is not only factual, but also shows a healthy amount of skepticism. Which is a very honorable trait in my book. And for having a good sense of humor and/or sarcasm. Which I always appreciate. Because, you see, I can take it just as well as I give it.

On my avatar, I'm still waiting for somebody to recognize who that is...

Hint: His initials are E.T.G.

Back on topic, it may or may not be relevant to your issue. But when you floor it at 70mph is the transmission briefly downshifting into 3rd(Drive) before shifting back into 4th(O/D)? Or could it be that it's not doing that, when it should be? Next question being, if not, have you tried doing so manually?

And, the answer to your timing adjustment question is no. Not unless you've timed it with a light prior, and have marked the distributor port as to where the marker/pointer/indicator on the distributor lines up when it's timed correctly. Which, if that makes no sense to you, means that once you've established where the distributor needs to be set/clocked to achieve whatever degree of ignition timing advance it's always going to be in that same spot. So, let's say you want to set the timing to stock(10° BTDC). You attach a timing light. Find the stock setting. Then make a matchmark of some sort on the port(which also has a gauging area denoting minimum to maximum distributor/timing adjustment which the marker/pointer/indicator on the distributor will be within) showing where the marker/pointer/indicator on the distributor is. Then you'll never need to use a timing light to find the stock setting again. Just line the marks up.

Or, if you have the 1st generation of distributor used for this engine(which you shouldn't) you can just turn the distributor as far as it will go counter clockwise. That should be 10° BTDC. But that may only apply to my 88. I haven't quite been able to verify whether that's the case or not yet.

I'm not sure about the O2 sensor code being a factor. So I can't rule it out. You should fix that just in case.

sechott

I didn't remove the intake manifold if that is the plenum. I probably should to clean it out good, but is I'll wait for when I adjust the valve lash which should be next spring. I hear of people adjusting their timing by knack I never tried. I would think your biggest improvement would be getting the o2 sensor corrected. You might want to wait for that before you start with adjusting the throttle. Good luck.

gandude

http://en.wikipedia.org/wiki/Ed_Gein

MudHippy

We have a winner!!!

Congratulations gandude!!!

Hilux4Life

Either your motor is tired or you have an issue of some kind. I routinely drive 80 on the highway with no issues. The fastest I remember driving was one morning around 4 am I was rocking out and trying to stay awake and when I looked down the speedo was reading 92.

I wasn't redlining either. So that brings a up a question. Anyone know the top speed of these trucks? Just curious

TNRabbit

There's a governor that kills the fuel at 108 mph.

It comes back on around 100 when that happens.

Roofmaster

The answer to your question mudhippy is no.Thats actually what I was expecting when I punched the throttle was for the throw down cable to drop it down a gear accelerate then jump back up but it didnt.It does do it at lower speeds though.As for the distributor I believe its second gen.my tensioner for the pulley is hydrolic unlike my 89 which is spring.When I did the head gaskets and removed the distributor there was dot of paint indicating position which seemed to me was a factory mark so I just realigned it and it seemed fine.Same thing today to and from work,ran fine,plenty of power until I got to highway speed then it just seemed to be lacking.I rarely go fater than 65 anyway but I like to know I can if I need to.You know in case Im trying to outrun the Apocalypse.