99 2.7 No CEL Help

263,000

STARTING - will start when pumping the gas pedal, usually within 3-5 seconds. it's starts best when I let the vehicle sit for 2 hours. otherwise it'll take many tries to start (longest 30 min)

WARM UP - when started I have to keep my foot on the gas pedal to keep the engine from dying out. once engine is warm(5 min) I can let off the gas pedal & engine will idle fine.

CUTTING OUT - without a proper 5 min warm up, my engine will cut out when rolling to a stop light or stop sign, usually have to keep my "RPMs up" in order to keep my ride from dying out.
**will cut out every time I place into Drive or Reverse which makes parallel parking tough** still need to keep my RPMs up to keep my engine from stalling

SLUGGISH - randomly upon acceleration from rounding a turn & on freeway acceleration even when flooring it

Vehicle runs great after warm up, gets me to where I need to go. however I try to lessen my stop & go's running errands or doing deliveries


New - TPS, IAC, MAF, spark plugs, wires, battery, fuel filter changed a year ago & original fuel pump

The symptoms in your Starting, Warm Up and half of Cutting Out are what I experienced when my IAC valve was mucked up on a road trip. I'd say dig into the valve and make sure it's clean and working properly. When you replaced it, or your TPS, MAF and spark plugs, did you use Toyota/Denso parts? Factory parts of this nature are the best and are typically trouble free.

I've also replaced my TPS but I forget the symptoms I was experiencing. I believe I posted up here so I'll have to dig it up.

It could be your fuel pump. A good determining factor would be to park it facing up hill and see how long it takes to start.

I've got the 2.7 with 260k on it and I can't stop her. What kind of plugs did you install? The 3rz hates new fangled stuff honestly. After that I've never had this issue so I'm coming up empty.

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I did replace the sensors with OEM replacements from the dealer... so next on the list to R&R is my fuel pump & filter, when I had the time. time marched on & now, my vehicle wouldn't start up. got it towed to a shop. asked for them to diagnose my ride. fuel pressure was good at 40 psi, ignition system working correctly & spark plugs also in good condition. they did a compression test & got 30psi on cylinder #1
I am not losing/burning oil & no white smoke out the tail pipe. I have heard that 3rd Gens have issues with valves getting tighter. I'm maybe leaning into the direction of pulling off the heads & see if that's an option ..... more than taking the shops advice of upgrading to another engine. The cost maybe lower for rebuilt heads, but I'm looking into total cost for both options.....

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Kryptoroxx has a thread on here where he was dealing with a valve issue.
I just read through your original post and was going to lean that direction next, it seems that everything else was good to go.
I don't understand why the 2.7l in the 4Runner has this issue over the ones in the Tacoma but its something I wouldn't read into as much.
I would find Kryptoroxx thread and check your valve clearance, that might lead you back into the right direction of getting your 4Runner up and running again.
I will try to find my factory service manual and see if it can off any more input besides Kryptoroxx thread which is very informative.

update.....
new fuel pump, fuel filter, fuel pressure regulator, a clean tank, new coolant temp sensor, & fully charged battery

didn't get to do a leak down test but did get the engine to fire up by spraying starter fluid straight into the throttle body.* good news is that the engine sounds great when it is running, however it's a must to keep your foot on the throttle to keep the engine from cutting out. also, the engine seems to crank better with a battery charger on the terminals, without it attached, seems like starting system doesnt draw enough current to fire up on its own.. baffled why it's not starting up & running on its own after upgrading these key parts..*** dunno what to do next, any other testing practices or just keep buying new Vacuum Switching Valves?* Vapor Pressure Sensor?* an ECU? ignition coils?

Quote:

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Originally Posted by 1aimpire

update.....
new fuel pump, fuel filter, fuel pressure regulator, a clean tank, new coolant temp sensor, & fully charged battery

didn't get to do a leak down test but did get the engine to fire up by spraying starter fluid straight into the throttle body.* good news is that the engine sounds great when it is running, however it's a must to keep your foot on the throttle to keep the engine from cutting out. also, the engine seems to crank better with a battery charger on the terminals, without it attached, seems like starting system doesnt draw enough current to fire up on its own.. baffled why it's not starting up & running on its own after upgrading these key parts..*** dunno what to do next, any other testing practices or just keep buying new Vacuum Switching Valves?* Vapor Pressure Sensor?* an ECU? ignition coils?

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I recently had to replace my starter and right before it went it sounded just like you are talking about. After I replaced the starter and did the big 3 upgrade things are much better

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