Fluctuating idle and cuts out/on while driving

[lewisd]

I have 99 legacy wagon Brighton 2.2 and while driving along, accelerating or cruising, the engine just cuts out and drifts abrubtly and then kicks back in. After reading other threads and OBD COde, I've replaced the TPS, replaced coil, plugs and wires, air filter. Car has 233k mile on it. Right now just trying to get this throttle issue cleared up and then work on the engine light. dang Maryland emission testing is a pain in the butt. no state safety inspections required but you better have emissions test done every other year. just frustrated.

I now have a CANOBDII reader (craftsman 14063) for $50. my codes now are P1700 Throttle position sensor circuit malfunction (A/T) (even after replacing) and P1507 Idle Control System malfunction (fail safe). I replaced the TPS so after researching some more I'm leaning towards measuring knock sensor (intermittent code) resistance and then cleaning the PCV valve (if possible) before replacing and if that doesn't work, then the IAC valve. engine idle fluctuates intermittently and after letting off gas it sometimes almost cuts out entirely.

[Huffer]

I think you have a vacuum leak, or a dirty MAF sensor. The TPS doesn't usually go bad.

[lewisd]

I'll try cleaning the MAF sensor and replacing the IACV gasket.

[d1giPhux]

Yeah.. sounds like a MAF problem to me.. you can get some MAF cleaner from any auto parts store usually.. i know places like autozone etc carry it. 'CRC Mass Airflow Sensor Cleaner'.

[lewisd]

update: Hey everyone, I'm back with an update. I've taken off the throttle assembly and (I believe) the MAF sensor that is bolted to the top of the throttle assembly and cleaned both thoroughly. I replaced the PC valve. I then did the IAC Valve cleaning procedure listed on theendwrench.com about spraying engine cleaner (i used seafoam recommended also) down air intake while running engine. I also read the voltage going to the IAC solenoid valve (good) but the resistance check showed an indication of an open (infinite resistance). I"m thinking replace the IAC sensor solenoid thats attached to the metal assembly? Could it really be this neutral switch someone mentioned? ALso someone mentioned TPS adjustment but after reading other threads, I don't believe that applies to my 99 2.2 (CAlifornia emission). My chiltons mentions it for earlier models. ANyhow after the codes were cleared, engine ran great for a while. idle was better and no throttle cutting out while running. now a couple days later it's back. The CEL does not always come on while it cuts out. when it does I get the P1507 code again. I'm having trouble attaching my Throttle body cleaning pictures

Parameter Description Value
DTC for which Freeze Frame was Stored P1507
Fuel System 1 Status Closed Loop
Fuel System 2 Status Not Supported
Calculated LOAD Value 8.63 %
Engine Coolant Temp 195.80 °F
Short Term Fuel Trim - Bank 1 -3.91 %
Long Term Fuel Trim - Bank 1 0.00 %
Intake Manifold Absolute Pressure 8.88 inHg
Engine RPM 1,691.

not sure why engine rpm says that high. doesn't sound like it's that high, at least not at idle. it doesn't want to fluctuate or cut out until I apply gas.

[Huffer]

Your MAF sensor is NOT on the top of the throttle body.

It's the big sensor right after your air filter box next to the fender.

[lewisd]

I probably meant the IAC Valve on top of the throttle assembly. I don't have a MAF sensor anywhere between the intake and air filter on the plastic tubing near the fender. anyways idle no longer fluctuates and idles fine at standstill, but it still cuts out while driving and kicks back in abruptly when I move the accelerator. I've tried attaching pictures but I don't have a url to link to. Not to offend anyone, but I'm also signed up with ultimatesubaru . org. I do have pictures posted there.

[cazey1916]

Hi mate did you find out what the problem with your engine was. My car has the exact same faults and i am struggling to rectify it. I have a 1994 gt twin turbo and it shares the same faults as yours, engine cuts out while driving and i get no throttle then it kicks back in and some times cuts out at idle and the CEL comes on. Im at my wits end with it.

[Reason]

Upload your pics to photobucket.com or imageshack.com and show us pics.

[upstateclipse]

Yeah pics would help. You should def have a maf on the intake hose. One other thing to check is to make sure you have good solid ground connections. I had a similar problem on a customer's car and after about a half day of diagnosing it ended up being the ground cable near the starter being loose.

[lewisd]

I did not solve the cutting out issue yet. After reading posts and getting edumacated, I saw I was way past timing belt change and began to hear what sounded like rough idler bearing noise. Decided to take care of that first. Anyways it's in my garge right now apart with new water pump, new cam seals (they were leaking slightly), idlers, tensioner (was leaking to). I had to send replacement belt (mitsuboshi)back as it had a tooth with exposed fiberglass strands and one was broken sticking up. the old belt was not frayed or cracked but was glazed and not real flexible. I'd say it had 140,000 miles on it. If I hadn't mentioned it before, my 99 legacy EJ22 automatic is a California emission type. someone said a phase 2 ej22. seems like it as some parts from a 2.5 on it. My oil pump backplate screws are still are still pretty darn tight. I'm trying to figure out how to hold the cam sprocket still to torque the bolt in. I loosened them while the old belt was on still and a stout long screwdriver in the flywheel (down the little acces hole behind the throttle assembly) holding the crank from turning. maybe i can do the same tightning them but someone mentioned belt may stretch or skip a tooth. I heard Autozone may have sprocket pulley holders to loan so may give them a call.

Once the TB job is done (and it still runs) I'll look back into the prior issue. what I have done with no success was new throttle sensor (no adjustement required on mine) and a new knock sensor. after the knock sensor was replaced it seemed to go away but then came back. My next suspect is a so called neutral switch or clogged fuel injector?

[Huffer]

Sounds like you have one of the mongrel 99 engines then...! Pics will definitely help us out.

[lewisd]

okay, now I have a photobucket account. I'll can add pictures of my TB work. another difference seems my 2.2 has a 2.5 tensioner type, also the right cam sprocket is all solid black hard plastic and the left is the metal spoke type.

http://s782.photobucket.com/albums/yy109/Dino41/99%20Subie/?action=view&current=IMG_1422.jpg

http://s782.photobucket.com/albums/yy109/Dino41/99%20Subie/?action=view&current=IMG_1426.jpg

http://s782.photobucket.com/albums/yy109/Dino41/99%20Subie/?action=view&current=IMG_1421.jpg :smt031

[lewisd]

Okay, here's my hypothesis. I just finished doing my timing belt work and when I put everything back together I cleaned up my spark plugs up as much as I could (didn't have new ones to put in at the time) and put them back in. the first 50 miles it purred like a kitten just like a year and a half ago after I put in a new ignition coil, wires and plugs. It had the same symptoms then and now they're back. After lots of forum searching I read how oil can seep slowly through those seals (when old) and foul the plug(s). causing rought idle, misfiring, etc. I notice a light oil film at the threads each time I took them out. Since my valve covers and plug seals are original and slightly leaking, I'll replace them anyway and hopefully that will fix that. I'm gonna order the gaskets this week and hopefully do it this weekend. till then I picked up four new plugs that should spark easier and stronger than the old prematurely worn ones in now. did that make sense? I'll keep you posted.