2002 RX300 AWD

Current problem: Car cranks and starts, then immediately stalls unless gas pedal is applied. This is happening for cold and warm starts. I kept my foot on the gas with RPM's at 1500 until it was fully warmed up but it still stalls after releasing throttle. Started today immediately after adjusting banjo bolt to fix small fuel leak at bank 2 fuel rail.

History: A few weeks ago I replaced the rear valve cover, PCV valve, spark plugs, and knock sensors. After the repair the car was running much better then after about a week a P0174 (bank 2 lean condition) error code appeared and the smell of gasoline began to be present when the car was running. The car still started and ran fine, just some hesitation on initial acceleration and the gasoline smell. I was looking at the engine a couple hours ago and noticed wetness around the bank 2 (towards radiator) fuel rail at the right hand side where the union/banjo bolt connects the fuel line. I noticed that the union bolt and the fuel rail both have paint dot markings and that they were not aligned. I started the engine and went back to look and found a small dripping of gasoline at the banjo bolt. I shut off the engine, tightened the bolt another 1/3rd turn so the paint dots aligned.





Now the car won't stay running and stalls out immediately although the engine sounds good when running and the gasoline smell is gone. I disconnected battery negative for ~5 minutes to reset the ECM but the stalling persists. Current fuel level is approx 1/4. The RX300 appears to have a self-purge to remove air from fuel lines (my first thought was I had introduced air into the rail which caused the stalling). No new CEL has appeared but the engine hasn't been run much and not driven at all since this began.

The car has not had starting, or idling problems prior. I'm wracking my brain trying to figure out how seeming to fix a small fuel leak at the fuel rail turned into a car stalls every single time.

 

Have you looked into the IACV (Idle Air Control Valve)? Search the stickies for how to clean it.

 

I had that thought but couldn't work out in my mind how it would immediately go from zero starting problems to full on idle failure because I thought the routine IACV issues tended to present themselves in a more gradual onset.

Especially knowing I had just tinkered with the fuel system I assumed the cause would be elsewhere. I'll go through the IACV information anyhow. I know enough to know I don't know much.

 

Banjo bolts usually have a copper crush washers [one on each side]. They should be replaced and you need need to use crows-foot open end and torque wrench. Remember to use the formula to compensate the reading as there is an offset. I cheat and turn the crows foot 90degrees to keep the same torque arm. I know folks and mechanics do wrenching bit I am very particular about doing the job by the book.

Salim

 

Hi Salim, I really appreciate what you've done at CL. I've been a lurker since owning my 1993 LS400 and now this 2002 RX300.

I remember those crush washers from doing the brake job on the rear. Where the brake lines meet the caliper. I'll get some new ones for this fuel rail and perform the IACV maintenance as well. This idle issue has me all confused because it seems like I had a pretty great running car one moment, tightened the fuel rail bolt, and instantly broke the car lol. Anyhow, thanks again.

 

I cleaned the IACV this morning and reset the ECU. It's back to running, starting, and idling just fine. The IACV definitely needed it - when I took the sensor off and tried to move the peg underneath that opens and shuts the valve it was gummed shut and had to be broken free with mild constant pressure. Even moving it through it's range of motion found plenty of resistance that was all removed by cleaning.

I had kinda hoped that by fixing the fuel rail leak and cleaning the IACV (replaced MAF ~10 months ago and just cleaned it again just in case) my P0174 would go away but no luck there. After test driving the car and playing with my new bluetooth OBD2 scanner I found pending P0174 and P0136 codes. I know these are two-trip codes so they'll likely trigger the CEL tomorrow when driving to work.

Thanks for the help. No idea how or why the IACV finally decided to stick coincidentally right after doing a different repair but it did and now we're good. Also, for those looking for an OBD2 scanner with live data/graphing but don;t want to spend $60+ this $22 BAFX bluetooth scanner seems to be the ticket. Much better than my crappy $20 Wal-Mart code reader lol.