93 J30 Idle Speed??? Need help with this one.

[robbie82lv]

Does any one know off the top of their head what the idle speed on a 93 J30 base is??? I'm guessing between 1,000-1,200 RPM's???? Mines idling around 600-750 right now. Also if I can adjust it myself with the throttle cable or is it computerized on this vehicle????

[GerryO]

Just about everything you need to know about determining J30 idle speed.

http://home.swipnet.se/e-solutions/IdleTech.html

http://home.swipnet.se/e-solutions/IdleTech2.html

For a fully warmed up engine, transmission in Drive, AC and alternator OFF, wheels pointed straight (no load on the PS), and at a full stop with your foot on the brake pedal, you sound pretty good to go.

[J30tChumpCar]

You are good, is there stalling or something bugging you?

1000 is way high for any car unless you have a hot rod with a bigger camshaft that refuses to idle low without stalling.

[driverdriver]

My car with transmission in park, engine fully warmed, idles in the 650-700 rpm range. Its been doing that since new. That's normal.

[robbie82lv]

It stalls occasionally if I've been driving around a lot. But it's mainly like it's getting no gas. I had the fuel pump tested it's good I crawled under it this morning and found a hole in the exhaust piping so I'm hoping that's all it is.

[yodawill2000]

Where was the hole ??
Before or after that cats ?

[robbie82lv]

About the midway point in the piping near the end of transmission start of rear differential before the cats

[J30tChumpCar]

The exhaust leak is not your issue, try something simple first, clean your throttle bodies.

[1994 infiniti j30 190+]

if you have an o2 sensor after the cat it could mess up the readings it is getting with a leak. also if the hole is befor the first o2 sensor then it will also mess up those readings. reason why a leaking exhaust could cause this if its befor an o2 sensor is because the exhaust would be pulling in more air than there should be into the exhaust causing issues.

[robbie82lv]

I'm gonna take it tomorrow to have the exhaust pressure tested along with the o2 sensors. I checked everything else the throttle bodies are spotless and properly functioning. I don't have the equipment to do the pressure or sensor testing.

[J30tChumpCar]

The job of the rear o2 sensors is ONLY to monitor catalyst efficiency, you can rip them out with no change to driviability ,the he only effect will be a engine light indicating the missing o2 sensors. Engine mixture is determined by the sensors located in the ex manifolds.

Pre OBD2 cars like yours are not equipped with rear o2s, pressure testing the exhaust is also a improper track as a clogged cat or muffler will create flow problems and choke in the mid to upper rpms, not idle where there's minimum flow.Same goes for the fuel pump.

I do not know where the problem lies but you have to think about other things, swap the idle motor?