I have been reading a lot of the posts on this topic that seems to be the norm as the 3FES get up their in miles like my 89' with 174K miles does. The latest post that I have been following suggests that it may be my TPS Sensor but I wanted to run everything by you guys before I spend any more money than the ridiculous amount that I already have. I have tried to follow the FSM but being stupid I have done a lot of unneccesary parts changing along the way (always thinking that must be it
.) Here goes a little background info.
In Park it idles roughly at 650RPM, sometimes dipping a little down, with the steering wheel visibly shaking. When I first start driving it, it really stumbles on itself for its first block driven, then that goes away (quite embarrasing every day in front of the neighbors with their useless new Porche Cayenne). Once warmed up and I stop at a light it dips down constantly to 550RPM where it wants to stall but hasnt. Flipping on the A/C is annoying but brings the RPMs up enough to settle her down.
It has 174K (almost as good as new compression as it was babied its entire life by my uncle who never brought it over 3000 RPMs.) on it and the motor has never been opened. Never even had its valves adjusted. I have given it a full tune-up with all Toyota parts, replaced the MAF, fuel pressure regulator, cold start injector (which was actually leaking gas down and somehow out the gasket of the EGR), checked and cleaned EGR, have found no vacuum leaks, everything is fine between the air filter and throttle body, repalced the coil, used fuel injector cleaners, replaced the very expensive 3 out of the 4 sensors around the thermostat housing. One was the temp sensor for the computer, the Thermotime switch for the cold start injector, and the third which I have forgotten what it is for. The IAC valve clicks three times when shut her off so I assume that it is ok. The O2 sensors are original (stupidly werent even changed at the 60K mark when Toyota replaced them for free back in the day). They are totally rusted on and can't be changed without changing the down pipes which are on the original converters for good. I dont want to get into that project yet as no check engine lights have ever been on.
The reason that I am now questioning the TPS sensor is that in Park I have found that if I bring her up to 1200 RPMs and hold it their, the idle goes up and down. Doing the same thing (if not worse) as when I am sitting at a light when it starts to dip down to 550RPM and back to 650RPM.
Thanks in advance for your help.
.) Here goes a little background info. In Park it idles roughly at 650RPM, sometimes dipping a little down, with the steering wheel visibly shaking. When I first start driving it, it really stumbles on itself for its first block driven, then that goes away (quite embarrasing every day in front of the neighbors with their useless new Porche Cayenne). Once warmed up and I stop at a light it dips down constantly to 550RPM where it wants to stall but hasnt. Flipping on the A/C is annoying but brings the RPMs up enough to settle her down.
It has 174K (almost as good as new compression as it was babied its entire life by my uncle who never brought it over 3000 RPMs.) on it and the motor has never been opened. Never even had its valves adjusted. I have given it a full tune-up with all Toyota parts, replaced the MAF, fuel pressure regulator, cold start injector (which was actually leaking gas down and somehow out the gasket of the EGR), checked and cleaned EGR, have found no vacuum leaks, everything is fine between the air filter and throttle body, repalced the coil, used fuel injector cleaners, replaced the very expensive 3 out of the 4 sensors around the thermostat housing. One was the temp sensor for the computer, the Thermotime switch for the cold start injector, and the third which I have forgotten what it is for. The IAC valve clicks three times when shut her off so I assume that it is ok. The O2 sensors are original (stupidly werent even changed at the 60K mark when Toyota replaced them for free back in the day). They are totally rusted on and can't be changed without changing the down pipes which are on the original converters for good. I dont want to get into that project yet as no check engine lights have ever been on.
The reason that I am now questioning the TPS sensor is that in Park I have found that if I bring her up to 1200 RPMs and hold it their, the idle goes up and down. Doing the same thing (if not worse) as when I am sitting at a light when it starts to dip down to 550RPM and back to 650RPM.
Thanks in advance for your help.
. You say to pull the codes. Would there be any point to this as the engine light has never been on. Or would the computer store some codes without setting off the light???
