roboskittle

Well I now have new problems with my RX7. It is an 88 GTU with about 135k on the clock. Things that are done to it are Throttle body mod, all emissions removed along with rats nest removal. New injector o-rings and lower grommets. New fuel line from the hard line to the filter, to the hard return line. I have 3 vacuum lines going to the fpr, boost sensor, and the vacuum nipple under the intake manifold that is supposed to help with fuel atomization. All these are brand new. I also have removed the OMP and put bolts in place of the injectors and am running premix. I added an extra ounce or two on top of the 1 ounce per gallon that everyone else has run. TPS was set using a multimeter at 1k ohms per the manual. I have also relocated my battery to the passenger side compartment behind the seat. In the process of this the resistor that is supposed to be hooked up to the oil pressure wire broke off at the resistor. Also there is a sensor on the bottom of the engine that goes into what i think is the oil pan. Anyways this sensors wire did the same thing that the resistors wire did. It pulled out. The sensor that is behind that one is fine. Before I did the battery relocation everything was fine. Now when I start the car it ran great other than me having to hold my foot on the petal till it warmed up. Well in the process of doing this I was holding it to about 3000 rpm when all of a sudden the engine sound changed dramatically and the rpm dropped off a little bit. So I reved it a couple of times. During this it backfired and it was a lot louder than the normal non cat equipped car had sounded before. I shut it down. Pulled the battery connections just in case and started inspecting. The first thing I looked at was the wiring I had just done. Nothing bad there. I than checked the plug wires all were good and these are new by the way. I also remembered not putting the clip back on the AFM connector but it had not fallen off. I pushed on it to make sure it was seated all the way and it was. I than pulled the plugs out to see how they looked. All were fine and not saturated with fuel the were perfectly dry. Threw them back in connected the battery back up and it ran fine again and would hold a decent idle at about 800. So I went for a drive. Almost immediately after I left the driveway it happened again. It seemed like it was only running on one rotor. I limped it back into the driveway and shut it down again. I smelled the exhaust and im not geting any smoke or any kind of weird smell. I did find it weird that it didnt smell like anything at all when it usually smelled like fuel. The car did sit for 2 years and I am about to dig into the fuel system and check it out. I did drain the tank before I put new fuel in along with the premix and I didnt see any chunks or crud in the fuel that came out. Just wondering if anybody else has experienced anything like this and what was the fix. I tried to list everything that was done with the car to give some detail and help pin point things faster. Oh I also changed the oil and filter the same night I did the battery relocation. I used Castrol GTX 20w50 and the oil level is good. I also have a new Upper intake manifold gasket intalled as well. Any help is greatly appreciated. Thanks, Jeremiah.

Icemark

Tough to read Jeremiah without paragraphs.

Sounds like one rotor is dieing if I am understanding what you wrote.

Have you done a compression check yet? I actually am suspecting a stuck Apex seal on one of the rotors.

glhs0867

I had same type of problem on my GTU, I had a slightly askew TPS setting, nothing more, nothing less.

This strange situation had me thinking I had blown 1/2 the engine.

However, I seem to get more performance, the more I tweak the TPS ranges. This is probadly just one of those things that the mind tell me its faster..lol


Hope that helps.

If the seals are stickin, put some MMO right inot the leading plug holes, use some old plugs and use them to start the car, then after you get your seals working, put your new plugs back in, and change out the oil again, you could probadly get away with using the filter still for another 1000 miles.

I have alot of friends with higher mileage RX7's and all of us change oil every 1000 miles, with the filter. Just our wy of saving on wear and tear.

roboskittle

Well I pulled the fuel pump out and oh my goodness.... I didnt think that a car that sat for over 2 years would have suck a beautiful gas tank. No sediment in it, no rust on the walls, not even a hint or trace of anything stuck on the fuel sock. I thandropped the filter and nothing but clean gas came out of both sides of the filter and i blew through it with no resistance whatsoever. Cool its not fuel related. Also when I had the injectors out to change the o-rings the filters at the top of the injectors were beautiful also.

Now on with the bad.... I went ahead and checked the TPS adjustment again. I hooked up and it read about 1030 ohms. So all was good. I than ran it out to full throttle very slowly. Everything was nice and even but once it was full open I would get anywhere from 6.8k to 11k ohms. I know this is bad as it should be 5k to 6k ohms. So I pulled the TPS and tried to clean it. It seemed to slide in and out a lot smoother than it had been which is good. I probed the backside of the connector again and checked the sweep. It was solid accept it was still high on the topside. I put it back in and the adjustment was way off again. I could never get it dialed perfectly back in to 1k ohms. The closest I got was about 986 ohms. So i said to hell with it. Jumped back in the car started it up and it idled perfectly without me touching the gas at all. I noticed I had left the lights on last night in the interior so I went to turn them off and before I was able to even touch them it stumbled and died again. So I went back and probed the TPS again and had 860 ohms on the TPS. WTF???? I than sweeped it out to the highside and it went off scale. Went to next highest setting and was getting 60k-99k ohms.

I am calling it a bad TPS for now and will be searching for another one. Hopefully this will end up fixing my problems. Thanks for the help guys, Jeremiah.

Acesanugal

iTrader: (5)

Even so, do a compression test as IceMark suggested. If it comes out erratic or somewhat poor, try seafoam. Don't believe all of the controversial crap about the stuff, it's fine. First give it a good go through the vacuum lines. If you don't absolutely need the car for 2-3 days, then pull the EGI fuse and suck a bit more into the motor by running the starter. Let it sit. Works wonders.

roboskittle

I did a compression check when I first bought the car. All was good and even across the board at 95 on all three for both rotors. Im not saying that it couldnt have gotten worse but im hoping it didnt. I will check this while im waiting for a TPS. Thank you, Jeremiah.

glhs0867

Once you get a working TPS all will be good. Your TPS was doing it the whole time.

You might wanna try adjusting it more, it may decide to start going into range, however, I quit doing the range testing. I just use it as a rough guide to start with, I always fine tune the adjustment after I drive the car and see how if feels, etc. But thats how I do it...hope you get your car fixed right.

Cause mine was always out of range..but it hauls *** and has for over 20 years now.