I will try to explain this the best I can. I have an 90 4wd with the V6 in it. I have the 5 speed manual transmission. This thing has no power at all. It reminds me of when your in to high of a gear trying to drive. It acts like this until I hit about 3000 rpm, then it has a little power. Now if I take my foot off the gas pedal it clears. I am driving down the interestate in 5th gear trying to get past 60 mph. The air filter looks clean. I replaced the Fuel Pressure Regulator today and it didn't help. I do know that right now it gets about 8-9 miles per gallon. Any ideas?
My old dog has no gitup!! Help
- Thread starter Ekimrm
- Start date
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KidVermicious
New member
Tune it up. If that doesn't correct it, go down the troubleshooting list in the FSM.
Don't throw parts at it. Find the problem and fix it.
Footofgod
New member
While I agree that you shouldn't throw parts out of it, make sure the basics are in good shape.
-plugs and wires
-cap and rotor
-fuel filter
-O2 sensor above the cat
If you have never changed any of those things, then do it. That O2 sensor made a world of difference for my 91. Clean the intake and throttle body. Do a sea foam treatment.
The 3.0 has no power at 3000 RPM in 5th gear unless you are on flat road with no wind. I stay in 4th unless going over 70mph. 5th gear on the 3.0 is almost worthless.
-plugs and wires
-cap and rotor
-fuel filter
-O2 sensor above the cat
If you have never changed any of those things, then do it. That O2 sensor made a world of difference for my 91. Clean the intake and throttle body. Do a sea foam treatment.
The 3.0 has no power at 3000 RPM in 5th gear unless you are on flat road with no wind. I stay in 4th unless going over 70mph. 5th gear on the 3.0 is almost worthless.
itgogitrev
New member
It's funny that this thread came up. I have the same thing going on with mine. It's like there is no power until 3000 RPM and then...
I'm averaging about 310-315 miles a tank, so my mileage isn't abysmal. I did seafoam and plugs. Checked resistance on plug wires, looked good. Cap and rotor seemed to be in fine working order. New air filter and TB was cleaned as well.
I'll give the O2 sensor a look this weekend. I know this thing will never be fast, but I would like to give school buses and UPS trucks a run for their money someday.
I'm averaging about 310-315 miles a tank, so my mileage isn't abysmal. I did seafoam and plugs. Checked resistance on plug wires, looked good. Cap and rotor seemed to be in fine working order. New air filter and TB was cleaned as well.
I'll give the O2 sensor a look this weekend. I know this thing will never be fast, but I would like to give school buses and UPS trucks a run for their money someday.
A quick update. I replaced the fuel filter, plugs, and wires and had little improvement. In fact it was worse. It would barely run. While triple checking everything I noticed on the air intake tube, the previous owner had broken it and used tape to help seal it up at one of the connections. Instead of fixing it properly and replacing it, he used electrical tape, and it was leaking air. It got me wondering. Being 2 in the morning I knew I could not get a replacement so I used the old duct tape and seal it up better. A world of a difference. I am not saying that it is totally fixed, but I have more speed and when I drove home my gas gauge didn't move where as before I used a quarter of take. So later today I will run down to the local pull-a-part and snag me a replacement hose to fix it properly. I might also take the mass air flow sensor that is connected to it as a test, just to see if there is a change. Mainly because the parts there are below dirt cheap. I will also replace the rotor and cap, local auto parts dealer was out when I went for the plugs, wires, and fuel filter.
austintaco
Member
I had an 89 with a V6 and it ran surprisingly well. However, at about 145k the AFM or MAF computer went and I had to replace that. Later in it's life, it had a cycle of surging on the highway, almost like it was getting hit with a gust of wind and the wind would stop. I tried several fuel cleaners, but nothing helped. One shop said it was the transmission??!!
I though it was fuel related so I changed out the pump, but it was still chugging. Finally, I started with the basics and changed the spark plugs. Bingo. That was it.
After that incident, I found some threads on Sea Foam, and I decided to try it. That made a night and day difference in performance and mileage.
Try seafoam through the vac line, oil, and gas. After a week, change the wires and plugs and check your rotor and cap.
I though it was fuel related so I changed out the pump, but it was still chugging. Finally, I started with the basics and changed the spark plugs. Bingo. That was it.
After that incident, I found some threads on Sea Foam, and I decided to try it. That made a night and day difference in performance and mileage.
Try seafoam through the vac line, oil, and gas. After a week, change the wires and plugs and check your rotor and cap.
I replaced the rotor and cap tonight. Test drive proved to have a little more power. Still not slam you back in your seat power, but getting there. The current exhaust system is pretty horrible. It has a lot of leaks. I guess that should be my next project after getting the rear brakes working.
Footofgod
New member
Getting a new exhaust and o2 sensor shouldmake a huge difference. Faulty exhaust can rob your engine of a lot of power.
It is a lot better but I still have a little miss. Every once in awhile I get a little back fire. As far as error codes not sure, my check engine light isn't on. So I guess I have no codes. Could it be that the exhaust leaks and can't produce the correct amount of back pressure?
Bad_Vision
Moderator
NO
your vehicle will run with a open header so lack of backpressure will not cause power loss
your vehicle will run with a open header so lack of backpressure will not cause power loss
Bad_Vision
Moderator
time to test your AFM and TPS here is a link that has saved me so many times
Toyota 4Runner and Pickup: Cheap Tricks
Toyota 4Runner and Pickup: Cheap Tricks
Ok I checked the timing and it is dead on. I replaced the AFM. Which has helped but still isn't right. That helped with my rpm and dropped it from 1000 to 700. Now every once in a while it acts like it is going to die, but never does. Give it a little gas and it is all better. The exhaust still is crappy. I am also wondering if te coil could be weak or back to needing to test the tps.
