RF600

The independent front suspension doesn’t like to get lifted and play nice with ball joints. A 2’ lift is something that won’t put too much stress on ball joints. A body lift will help with giving the look of a lift without suspension issues. No idea what year your rig is, so I’m speaking generally.

Timing belt is done. The last time I changed it was 2012. I was surprised how good the belt looked. curious if anyone else bought the kit from Napa and had an issue with the water pump. The pump will mount, but the snout is too long. The water pump by itself was the same way. I had to order one from Oreilly’s. The water pump I did back in 2012 was purchased from Nissan. It was the same manufacturer as the one from Oreilly’s and Napa.

I tore my alarm out a while back. Not that I used it anyway. I just didn’t want to have any issues.

As to the possible overheating. I see you had a rad flush. I'm willing to bet you have some air in the system. Try turning on the heater and running it for a bit to circulate the coolant through the system to see if the bubble goes away. I believe there is a bleed screw on the back of the intake. There is one on the WD21's. If it's set up like the WD21, the radiator is not the highest point in the cooling system. So the bleed screw is there to get the air out. I had a little air bubble in mine and it was acting weird. It would get hotter than normal and drop very little when driving. At the time it was over 100* so It wouldn't have cooled down much while driving. For the oil leak, you need to get under the vehicle and see what's leaking. If you can't tell, you would need to clean everything and then drive it to see if you can find where it's leaking.

Next up, timing belt and all that goes into changing it.

So I finally figured out what the issue was. It was the injectors. Not sure if a couple were plugged or what exactly. After replacing them, it idled like it was supposed to. Passed smog no problem. Thanks for everyone’s help.

I figured I would start over and check the TPS. I didn't really check it very good the first time. I was able to get the TPS to read. The manual says it should go up to 9 ohms resistance. The best I could bet was 7.3 ohms.

Thank you for the follow up. Mine looks like yours does in the pic. I haven't tried to put 12v to it and see what happens. The injectors ohm test within spec. I know that doesn't mean much. I wouldn't think the injectors would cause the up and down when holding the engine speed around 2K. I would think a sensor is malfunctioning. Something like the MAF or TPS acting up?

If you have the spare time to do that, I would appreciate it. I don't really know why it's running as poorly as it does. I agree, it doesn't make sense. Fresh tune up, no vacuum leaks, no codes, not really anything points to why it runs like it does. Since I haven't really haven't much with the injectors, I guess they might be worth looking into?

The plate on the inside has about a 40 degree open to close. It's about half way open currently. It operates freely. No binding, no signs of any soot or anything else. Would you expect the idle to suffer with it stuck half way? Most of the time when I start it cold it will jump up to high idle, but drops pretty quickly. If it doesn't go to high idle, it will struggle to idle properly.

The last time I pulled the plugs they were all white. Not wet. So lean fuel mixture and hot cylinder temps. The iac seems to be operating properly. I'm leaning towards the pulse air valve, or whatever it's called. It ohm's out good. I pulled it apart to look and see what is in there. Since I can't get a picture that will fit under the 64kb, I will try and explain it. There is a plate inside that is spring loaded. The plate has a slot that will open or close depending on the coolant temp, my assumption because the coolant line runs through a plate that is mounted to the plenum, then this valve is mounted to that. I tried putting it in the freezer and the plate didn't move. I tried heating it up and the plate didn't move. At this point I believe that this pulse valve is not operating like I think it should. The plate is stuck on the almost closed position. I assume when it's hot the plate is supposed to be in the open position, allowing air to pass through it. I'm half tempted to make it so the valve is always open to see what happens. I'm guessing at this point. I don't really have any other explanation of what could be happening. No vacuum leaks. I smoked the system.

AI says the iac valve is the likely issue. By now I can get the plenum off fairly quickly. lol. I guess that’s what I will check or replace next. In reality I can’t really complain. I have 305k miles on it and I have really not done anything besides regular maintenance. I will report back after I get to that.

I haven't driven it that much. The times I did drive it, I didn't notice the rpm issue. I would have to drive it again and pay more attention to things. I didn't think to use AI as possible help. At this point it isn't going to hurt.

The old distributor was doing the same thing

I cranked it as far as it would go until it hit something and stopped.