TylerT252525
New member
Long post ahead.
Id like to thank everyone who post. I’ve found so much info on here and this is my first time posting.
So I’ve recently picked up my first 4runner and I’m now struggling to figure out what my issue is with my project.
Truck: 2001 4Runner 2wd SR5 3.5 5vz 214,000 miles
I picked this 4runner up for 500 bucks. I purchased it under the impression that it had bad head gaskets and I was willing to take the risk and I figured I could have a good beater vehicle for pretty cheap with a little bit of work. When I purchased it, it would crank, run, and drive but obviously had issues. It drove around the block and into my garage before I got to work.
After further investigation I found that it had zero compression in cylinder 4. Once I pulled off the driver side cylinder head I found that the rings in cylinder 4 were toast and the cylinder wall was severely damaged.
After finding this out, I decided I would pull a motor from the junkyard, replace the head gaskets, timing belt, and water pump while everything was accessible on the engine stand and swap it in.
My donor motor was from a 2002 tundra 234,000 miles. I looked everything over before I pulled it. The motor turned over freely, oil looked great, I could tell it the valve cover gaskets were replaced, and the truck was used commercially so I was willing to bet it was serviced regularly since I could see evidence of several oil change stickers in the windshield.
When I got it home and tore it down to the short block everything looked great. No play in the pistons and good cross hatching on the cylinder walls. I used the kit from yotashop to replace the head gaskets, head bolts, valve cover gaskets, and intake gaskets. I replaced the timing belt, water pump, and thermostat with aisin products. I also put new plugs, coil packs and wires on it.
I pulled my wiring harness all the way out of my 4runner so I could connect everything on the engine stand instead of trying to fight the connectors in the tight spaces in the car and it worked great.
I dropped my freshened-up junkyard motor in, bolted it up to the transmission, connected my wiring harness back up, hooked all my vacuum lines up and was ready to go.
After realizing I missed one ground wire from the cylinder head to the firewall, I got it running. It was running a little rough and had a check engine light. One code was for the upstream O2 sensor and one was for the MAF sensor. I let it idle for several minutes to let the ECU learn and then I tried to drive it around the block. (This is where the issues start)
It started to run rougher when I put it in gear and the motor had a load on it. When driving it had very little power. It would basically be very hesitant to rev up and it would take several seconds just to get to about 25MPH. I could tell something was way off.
When I was on my way back home I noticed the red oil light on the dash would come on when the RPM would go over about 1200.
I immediately parked it and checked the oil level (it was at the top dot). When changed the oil when putting it back together I used high milage 10w-30. When I cranked it again to check the light the same thing happen. At idle- no light. When I reved it up – it would eventually flicker and come on around 1200RPM. I checked the electrical connection at the sending unit and everything was good. There is no knocking or any sounds coming from the engine and every cylinder has good compression. There is also plenty of oil in the top of the engine. If I had an oil pressure issue wouldn’t the light come when the engine is at low RPM?
I went ahead and replaced the MAF and upstream O2 sensor and cleared the codes. When I cranked it after this the engine was idling great (I was really impressed with how smooth it was) even under a load in gear with my foot on the break. I went to take it for a test drive and same issue. Hardly any power, struggled to reach 3500RPM, and the oil pressure light came on when the engine was over about 1200RPM. When I got back home I put it in park and put my foot on the floor. The engine would not go over about 3500 RPM. It is like it was hitting a limiter. Shouldn’t the engine redline even in park or neutral?
I am completely stumped on what my issue could be. There are no codes stored, the fuel trims look great, the engine is not knocking or smoking, I have checked the fuel pressure (it was great), replaced the fuel pump, checked for any vacuum leaks, and cleaned the throttle body, and double checked the timing belt installation was correct. I have not checked the oil pressure yet with a manual gauge but other than that I am at the point where I’m not sure what to do.
Does the oil pressure have anything to do with it having such little power?
Thank you so much for any responses.
EDIT: I was doing some reading. Could it be an issue with the ECU since I used the harness and ECU from the 4runner? I used the 4runner throttle body btw
Id like to thank everyone who post. I’ve found so much info on here and this is my first time posting.
So I’ve recently picked up my first 4runner and I’m now struggling to figure out what my issue is with my project.
Truck: 2001 4Runner 2wd SR5 3.5 5vz 214,000 miles
I picked this 4runner up for 500 bucks. I purchased it under the impression that it had bad head gaskets and I was willing to take the risk and I figured I could have a good beater vehicle for pretty cheap with a little bit of work. When I purchased it, it would crank, run, and drive but obviously had issues. It drove around the block and into my garage before I got to work.
After further investigation I found that it had zero compression in cylinder 4. Once I pulled off the driver side cylinder head I found that the rings in cylinder 4 were toast and the cylinder wall was severely damaged.
After finding this out, I decided I would pull a motor from the junkyard, replace the head gaskets, timing belt, and water pump while everything was accessible on the engine stand and swap it in.
My donor motor was from a 2002 tundra 234,000 miles. I looked everything over before I pulled it. The motor turned over freely, oil looked great, I could tell it the valve cover gaskets were replaced, and the truck was used commercially so I was willing to bet it was serviced regularly since I could see evidence of several oil change stickers in the windshield.
When I got it home and tore it down to the short block everything looked great. No play in the pistons and good cross hatching on the cylinder walls. I used the kit from yotashop to replace the head gaskets, head bolts, valve cover gaskets, and intake gaskets. I replaced the timing belt, water pump, and thermostat with aisin products. I also put new plugs, coil packs and wires on it.
I pulled my wiring harness all the way out of my 4runner so I could connect everything on the engine stand instead of trying to fight the connectors in the tight spaces in the car and it worked great.
I dropped my freshened-up junkyard motor in, bolted it up to the transmission, connected my wiring harness back up, hooked all my vacuum lines up and was ready to go.
After realizing I missed one ground wire from the cylinder head to the firewall, I got it running. It was running a little rough and had a check engine light. One code was for the upstream O2 sensor and one was for the MAF sensor. I let it idle for several minutes to let the ECU learn and then I tried to drive it around the block. (This is where the issues start)
It started to run rougher when I put it in gear and the motor had a load on it. When driving it had very little power. It would basically be very hesitant to rev up and it would take several seconds just to get to about 25MPH. I could tell something was way off.
When I was on my way back home I noticed the red oil light on the dash would come on when the RPM would go over about 1200.
I immediately parked it and checked the oil level (it was at the top dot). When changed the oil when putting it back together I used high milage 10w-30. When I cranked it again to check the light the same thing happen. At idle- no light. When I reved it up – it would eventually flicker and come on around 1200RPM. I checked the electrical connection at the sending unit and everything was good. There is no knocking or any sounds coming from the engine and every cylinder has good compression. There is also plenty of oil in the top of the engine. If I had an oil pressure issue wouldn’t the light come when the engine is at low RPM?
I went ahead and replaced the MAF and upstream O2 sensor and cleared the codes. When I cranked it after this the engine was idling great (I was really impressed with how smooth it was) even under a load in gear with my foot on the break. I went to take it for a test drive and same issue. Hardly any power, struggled to reach 3500RPM, and the oil pressure light came on when the engine was over about 1200RPM. When I got back home I put it in park and put my foot on the floor. The engine would not go over about 3500 RPM. It is like it was hitting a limiter. Shouldn’t the engine redline even in park or neutral?
I am completely stumped on what my issue could be. There are no codes stored, the fuel trims look great, the engine is not knocking or smoking, I have checked the fuel pressure (it was great), replaced the fuel pump, checked for any vacuum leaks, and cleaned the throttle body, and double checked the timing belt installation was correct. I have not checked the oil pressure yet with a manual gauge but other than that I am at the point where I’m not sure what to do.
Does the oil pressure have anything to do with it having such little power?
Thank you so much for any responses.
EDIT: I was doing some reading. Could it be an issue with the ECU since I used the harness and ECU from the 4runner? I used the 4runner throttle body btw
