LC low idle / stalls after replacing starter

Joined
Sep 10, 2021
Messages
13
Location
Tacoma, WA
Hi all, mud has been such a lifesaver (longtime lurker here) so I'm hoping to get some help on my issue.

My 2002 LC (230k miles) didn't start one day. It ran wonderfully before this. I replaced the starter myself (turns out the pinion gears were completely jammed). It starts and cranks like a dream now. However, immediately after and ever since this job, it idles very poorly (300-500 RPM) with the engine sputtering, revving up back to life, and back down, you know, the tachometer needle bounce. Twice it has stalled.

I took it into a Toyota dealership for a diagnostic and they literally told me the AC compressor is failing, drawing too much power from the engine, causing my low idle. I am but half a monkey but even I know thats BS. The AC compressor is powered by the engine serpentine belt, so the engine has to run harder in order to power the AC. When the AC is on, the RPMs go up, so if the AC was drawing too much power, I'd maybe have a high idle issue. I have a LOW IDLE issue! And on top of that, the low idle issue happens when the AC is off! I in fact had to drive to the dealership with the AC on full blast in order to keep my car from stalling. I told them all of this, I told them it's something to do with the parts I touched when replacing the starter. My AC compressor has been making intermittent though relatively quiet noise since day 1 (still blows ice cold air though), it can't possibly coincidentally cause these problems starting the day after the starter replacement. No go. "The master technician is never wrong." :/

I could use your insight as to where to look next. Or, tell me an idiot and the dealership is right. My best guess right now is a fuel problem. When I replaced the starter, I did the following things that I think could be relevant to the low idle, in order of my perceived relevancy:
  1. Take off the Fuel Pressure Dampener (#2327050012) off the right fuel rail. When I replaced it, I replaced its 2 gaskets. This part spewed fuel everywhere upon first start up, causing engine to die immediately after start. I realized I placed the gaskets wrong. Went and got another pair of new ones and did it right and no more leaks after that. FSM (page SF-3) seems to say it should be torqued to 39 Nm, which I didn't do and plan to go back and do, not sure if this could be part of the problem.
  2. I accidentally kinked the fuel hose that comes out of the dampener for maybe a minute, didn't hear any cracks though.
  3. I took all 8 fuel injectors off the fuel rails and took them to get professionally cleaned. The guy cleaned them to 70 ml/30 sec flow rate. 2004 LC FSM (page SF-25) says the flow rate should be 56-69 ml/15 seconds ?! Before the cleaning, they were all lower, at around 60-something/30 sec flow rate according to the guy, so it has to be better than what it was, even if it's lower than spec? Or is the spec wrong here? I have a hard time believing cleaning the injectors would clog the fuel and be the problem here. Injector orings, grommets, insulators were replaced with new.
  4. I took off the 2 bolts and 2 nuts attaching each fuel rail to the intake manifold (as well as some brackets on the front and rear fuel return lines) in order to lift them an inch above the manifold and wiggle the injectors off. I did NOT take off or otherwise mess with the original Fuel Pressure Regulator (#2328050050); the two fuel rails were still attached to each other by the front and return lines during this process
  5. I removed the throttle body from the intake manifold
  6. I messed with the throttle cable a bit (took off the little beaded end from the throttle body) so it may have more/less slack than before
  7. I replaced the engine intake manifold gaskets (#1717150020) with Ajusa branded ones (OEM ones didnt come in in time), with the tiniest bit of silicon grease
  8. The other standard things that need to be done when getting to the starter (air box, etc). New air filter.
Mud gods, please let me know if there's something obvious I could have messed up after starter replacement that would mess with my idle now. What I'm thinking my next move is to take the fuel pressure (any tips and recommended tools?) and replace the fuel pressure regulator?
 
Joined
Sep 10, 2021
Messages
13
Location
Tacoma, WA
I'd check all of the air/vac and fuel lines for leaks first.
I had checked with a propane torch and couldnt find any vac leaks!

Aside question, do you think driving it right now would damage the engine, if it's a fuel pressure problem or a vac leak I havent found?
 
Joined
Aug 14, 2018
Messages
761
Location
Morrison, CO
Sounds like it needs a tune up generally. Big things that cause it to stall like that are holes or cracked in hose from power steering pump to intake, dirty throttle body, dirty idle valve, or failing COPs. Could be a weak or failing fuel pump you can have a mechanic test fuel pressure or rent a fuel pressure test kit from an auto parts store.
 
Joined
Sep 10, 2021
Messages
13
Location
Tacoma, WA
I think it just got fixed by doing the idle relearn procedure where you let the engine run in "Park" and with the parking brake up. Then I drove it around another 30 or so miles and I think the PCM relearned everything and now it's ok again. I didn't know you had to do this when the battery gets disconnected. Sigh. Now I'm at 500-600rpm at a stop in drive and 700 in neutral. Seems normal now. Thanks all.
 

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