[myothersupra]

I've searched here, Google, and other Toyota forums without any success so I'm hoping y'all can steer me in the right direction.

I have a 96 Camry DX I4 with just 123,000 miles on it now.
I bought it 18 months ago in fair to rough condition from a local Toyota dealer's used car division (where a friend works) after the original female owner traded it in with all sorts of little issues, a few mild dents, a steaming radiator, and an obvious lack of maintenance although the date and mileage intervals on oil change sticker were current so at least she was trying to do the right thing...
I replaced the bad factory radiator, did a full timing belt job because the tensioner was squealing!, gave it all new front seals (including front main), and installed plugs, wires, cap, and rotor too... ALL Genuine Toyota parts!!!

Also got a freakin' expensive Toyota water pump on a Gen2 Camry friend's recommendation but decided not to install it 'till the original one dies.

Thermostat also got overlooked in a rush to get it back together to go to work and then went forgotten for a while 'till suddenly the first winter cold snap hit and fuel economy and heat sucked and the car hung in 3rd with the tq converter unlocked for a long time every day so I installed the new Toyota thermostat and those issues all cleared up.

Now here we are with 23k of my own miles on it since I bought it and as I'm cruising down the interstate after a while (20-45 minutes at random) it starts stumbling and the tach starts falling fast as I hold the pedal steady, if I press the throttle more it bogs more, if the A/C is on it gets MUCH worse, if I back off it seems to help a little, but no matter what I do or don't do it just suddenly clears up and jumps back to life again like nothing bad happened, but within a couple more minutes it does it again and clears up again and does it again randomly once every few minutes.
When it does quit stumbling moments later and comes back to life again I can floor it and it revs up and pulls totally fine like nothing's wrong.
Sometimes it feels like a quick little miss that clears up again just as quick as it happened, others it's a full-blown bogging with the intention of stalling.
When the problem occurs it feels like it's running out of gas but it had 3/4 tank of fuel the first time it happened.
I've run errands around town many times since then to finish off that tank with no signs of problems. When the tank got low I replaced the fuel filter (Genuine Toyota filter, same part number as the one I took off) then I refilled the tank and at first that seemed to help and it got me to work just fine (50 miles each way on the interstate) and while still at work it got me to both lunch and dinner at separate times and went on several parts errands on that 24+ hour work day but on my way home from work it happened again...

I pulled the distributor cap thinking the shaft seal might've let go and puked oil in it but it's clean as the day I installed it.

It's freakin' OBD-II and the only code it has is P0441 Purge Flow Not As Expected, which has existed since long before I bought the car and always comes back within a day or less of being cleared out with the reader.

It can tell me to tighten the gas cap (was a stored code from previous owner when I bought it!) but it can't tell me it's about to stop running or at least that something's wrong??? WTH??? :headbang:

I assume that a clogged cat getting hot would trip an O2 sensor code?
I also assume an igniter flaking or overheating might trip a code too?

Since it's OBD-II I'm wondering...
Can it tell if the fuel pump is flaking? As in can it or does it monitor fuel pressure and/or the pump voltage signal?

With such "low mileage" on this car and the fact that it's supposed to be smarter with its' fancy OBD-II ecu I'm really suprised it's threatening to leave me stranded on the interstate and I'm really concerned about driving it to work anymore... My buddy's 92 I4 LE with over 200K miles just keeps going.

I would assume it's either a fuel or spark issue and that'd narrow it down to checking things like the coil and igniter since the plugs/wires/cap/rotor are all Toyota parts replaced 23k miles ago (Denso Plat plugs iirc), or maybe the fuel pump as things to check at this point, assuming it's things like those that the OBD-II system might not be able to "see"???

Toyota wants like $300 for a fuel pump (AFTER my buddy's employee discount!) and I don't have access to a spare coil or ignitor so has anyone else had these symptoms and what suggestions do y'all have?

Oil level is fine. Coolant level is fine. Coolant temp is always about 1/3 scale or less according to the stock gauge. No other idiot lights are on either.

Any guidance would be greatly appreciated as I've got to get this car back to reliable again asap since it's my only way to get to work and I can't afford to replace it right now and it's a suprisingly comfortable and economical commuter box, up 'till now anyway... :disappoin

 

[project92camry]

i would check the fuel pump. thats weird that the MIL dont give u any better info on wats wrong. did u ever change ur fuel filter maybe u got clogged injectors.

 

[Gibson99]

actually fuel filter may be suspect as it's cutting out at highway speeds. it's cheap and only slightly hard to replace. top bolt is fairly easy but bottom one can be tough.

have you replaced your gas cap w/ a new one to try to eliminate the p0441 code?

 

[myothersupra]

As stated in my o.p. I replaced the fuel filter with a brand new Toyota filter of the same part number shortly after the problem appeared. It did not solve the problem... and yes, the top banjo bolt was simple, the bottom line nut was a major pain to undo from the old filter and to tighten on the new one.

No I didn't replace the gas cap to kill off the P0441 Purge Flow code.
I'm not getting a gas cap code afaik...
I was under the impression that the purge flow code was either the charcoal canister breaking down and clogging things up or that combo vsv on the canister. Is that not correct?
I'd LOVE to not see the purge flow code anymore... almost as much as I'd love to have the car run properly again for my work commute...

 

[Gibson99]

sorry, i totally missed the fuel filter bit. also, i guess i was thinking p0441 was evap small leak. all i know is i hate trying to troubleshoot p044x codes.

either way, an evap code condition shouldn't cause running issues except possibly poor idle due to a vacuum leak or something.

it does almost sound like the fuel pump if you already replaced the filter. wouldn't hurt to take out the pump and make sure the screen on the bottom of the pump is still intact and clean - that doesn't cost anything to check. those screens are fairly cheap at auto parts stores if yours is falling apart.

 

[carsrus]

I could be a funky vacuum leak. A split line or soemthing some where that might be fine one sec and hell the next.

I doubt it the fuel pump since it runs fine after a few sec.

 

[project92camry]

this is going be hard to find if its a vac leak. hope its the fuel pump. like a short or sumthing

 

[Gibson99]

I doubt it the fuel pump since it runs fine after a few sec.

not necessarily. sometimes fuel pumps become intermittent before they quit entirely.

 

[myothersupra]

That's what I'm thinking at this point.
Since this began happening it seems to run errands off and on all day long with speeds from 20-45mph without complaining (at least so far) and I can usually go all the way to a friend's house 35 miles away or all the way to work 45 miles in the other direction cruising along at 78mph with the occasional pull to 95+mph to pass someone without noticing anything except maybe an occasional tiny stumble like one quick miss that you're not sure even was a miss while cruising at steady speeds, but at some point later that day on the way home it gets be half way or 2/3 of the way home and begins to really act up leaving me unsure if I'll stay running or make it home but so far if I limp it along gently when it's happening it will jump back to life again within a 5-10 seconds or less, let me get right back up to freeway speeds like nothing happened, and keep on going normally for a few more minutes 'till it does it again. It's really stressful but I almost wish it would just die and stay that way because at least I could have a better chance to find the problem then...
When it jumps back to life again I can actually floor it and it'll pull hard like always too...

For the past few months, normally when I go out to start it it fires right up on the 2nd or 3rd spin at the most. Other times it takes holding the key and cranking it for a few seconds or even a second try after like 10 seconds of cranking then it jumps to life as usual, and a few times since I bought the car (like 3-4 times total) I actually had it start right up then die immediately, turn the key again, fires right up, then falls to zero again, several times in a row. Each time that happened I finally turned the key while pressing the gas pedal and it stayed running but tach'd really high even after I let off the gas 'till I put it in Reverse and it settled down to normal. Weather conditions and whether or not it had been driven that day were not consistent either. Each time that happened, once it started and stayed running I could drive as far as I wanted, even on the interstate with no problems at all. That's also what tends to make me suspect a fuel problem like the pump wasn't running or something but I'm only guessing...
It's just so wierd.

 

[myothersupra]

Oh, the main air intake "accordion hose" (a Supra term apparently) that goes from the airbox to the throttle body is also a new Toyota part. The one that was on the car when I bought it was split wide open and I replaced it when we did the timing belt and tune up 18 months ago so it's not an intake leak.

 

[Mr.Nutcase]

Oh, the main air intake "accordion hose" (a Supra term apparently) that goes from the airbox to the throttle body is also a new Toyota part. The one that was on the car when I bought it was split wide open and I replaced it when we did the timing belt and tune up 18 months ago so it's not an intake leak.

Check fuel pressure off and car running
Also check the intake manifold gasket, Spray around the engine with Brake Cleaner or Carb Cleaner, If the RPM go up, then you have a vac leak.

 

[myothersupra]

I'll need to get a fuel pressure gauge of sorts apparently. I was thinking about an electronic gauge lke I had in my 87 Supra before Katrina flooded it so I could mount it on the pilar and glance at whenever the car acts up because it's hard to watch an inline gauge when you're driving down the interstate and it's under the hood but the electronic ones seem to be freakin' expensive.
It was a 1-owner car and the intake was never removed afaik but I'll give that a try.
Usually based on how a buddy's Supra was acting with an intake leak at the "plenum", a leak like that also tends to effects idle and drivability overall too and I'm not having idling issues.
I'll give that a try though first chance I get.

 

[Mr.Nutcase]

Also scan for codes, The FSM has tree-diagrams on how to test codes

 

[1996camry]

Fuel pump is the problem.

 

[Gibson99]

have you done a leakdown or dry/wet compression tests on it? my dad's '90 4-runner had the bad head gasket issue and it was doing something similar (though not as severe) as yours - occasional miss on the highway and minor power loss at times. compression was good, but leakdown showed the BHG. thankfully his old 4-runner was covered by that recall so he was golden.

 

[myothersupra]

Also scan for codes, The FSM has tree-diagrams on how to test codes

Reading codes on a 92-95 Gen3 Camry is OBD-I which is simple just like my MkIII Supras... Unfortunately my 96 Gen3 Camry is the only year Gen3 with OBD-II which requires a reader, but as stated in my o.p. I do already have a OBD-II code reader because my 98TT Supra is also OBD-II, P0441 is the only code currently/still being reported by my Camry, and that code has existed since before I bought the car. The other 3-4 codes that existed when I bought the car went away for good as soon as I cleared it but the P0441 always comes back which is annoying but shouldn't effect drivability, or at least it hasn't in the past 23,000 miles I've put on the car since I bought it.
Thanks for the guess though...

Fuel pump is the problem.

So you've had this problem also hopefully? If so what fuel pump did you replace it with? Toyota wants >$300 even with a buddy's employee discount for a new pump. I've been thinking about a Walboro like we put in the Supras that's supposedly superior and only costs a little over $100 new but I have no idea what the specs are for the Camry fuel pumps and which Walboros might be compatible or if there's a better alternative.

have you done a leakdown or dry/wet compression tests on it? my dad's '90 4-runner had the bad head gasket issue and it was doing something similar (though not as severe) as yours - occasional miss on the highway and minor power loss at times. compression was good, but leakdown showed the BHG. thankfully his old 4-runner was covered by that recall so he was golden.

It's not running warm or hot or using/losing any coolant at all even with the extra load of the a/c running on hot days and the oil doesn't look like a milkshake and the coolant's still that obvious Toyota Red so it's not a BHG...
and with "only" 123k miles on a 5S-FE which I was under the impression isn't even fully broken in yet as I've seen lots of 'em with >200k miles and a handfull with >300k miles on 'em so I would HOPE it's not a compression problem on this fairly young and totally stock 5S-FE engine...
Although a few of the I4 4Runners had issues your dad's probably also had the optional V6 engine I suspect, which like you said totally qualifies for the BHG Service Bulletin that most of the Toyota V6's from that era got and the I6 powered MkIII Supras didn't but totally should have...
I've owned at least a dozen MkIII Supras over the past 15 years so I'm VERY familiar with BHG symptoms that Toyota refuses to admit is a major problem with the I6 7M engines due to a factory head bolt torque spec miscalculation that they still deny to this day but 52 ft-lbs just ain't even close to enough to hold the head down tight...
Thanks for the suggestion but I know that's not it on this I4 Camry.
Had it been the V6 you could definitely be right as quite a few of them had the same problem as those V6 4Runners from what I've heard over the years...

P.S. I hope I don't sound unappreciative as that's not my intention!
I'm just a bit stressed over this situation at this point and I already took the time to put the history I know about the car in the O.P. along with everything I did to it when I bought it and the things I've already tried and checked since this problem apeared so we could try to better narrow it down in advance... It just really seems odd that it isn't telling me any codes regarding the fact that it's threatening to stop running on the interstate, especially being the fancy deluxe OBD-II system...

 

[Gibson99]

well keep in mind that in 96, obd-ii was still fairly new and they hadn't fine tuned it as much as they have by now, so diagnosing all sorts of odd problems like this wasn't as easy to do with 1996 software compared to 2006 software. today's ECUs have faster processors, more working ram/rom, and therefore can sample data faster and make better diagnoses and give better data as a result.

even my 98 shows more useful info than my 95 did (don't forget that 94-95 camry v6 was also obd-ii)

good luck with this. the p044x evap codes are my least favorite to troubleshoot because it involves so many piddle-shit parts that are not easy to test. the smoke test is also a pain to do even in a compeltely closed up shop, and the trouble codes give you so little to go on that it quickly gets frustrating. stupid emissions laws... we wouldn't even have an evap system if it weren't for them!

 

[96paseo]

Before pulling the fuel pump, you should check the igniton coil. You'll need an ohm meter. The specs for internal coil type are (primary = 0.4-0.5 ohms) (secondary = 10,000-14,300 ohms). External coil type specs are (primary = 0.3-0.55 ohms) (secondary = 9,000-15,400 ohms). If the coil is out of spec, replace it. Also check for hair-line cracks on the coil. To check the primary, put the meter across the positive and negative terminals. To check the secondary, put the meter across the positive terminal and the high tension terminal. The high tension terminal is located at the top of the coil.

 

[myothersupra]

Didn't get the chance to test the fuel pressure and got tired of trying to find a proper fuel pressure gauge for efi or a fuel pressure tester so I bought a fuel pump from O'Reillys today instead which had the correct electrical connector etc already on it, installed it myself and we'll see what happens next. The pickup sock/screen and the tank were both free of any debris as well which is why I chose to check on a new pump at the local parts stores. All the others had one that you had to cut the plug off the car's harness and splice them into two slip-on lugs and the base of the pump didn't look like it would fit in the hanger assembly at all so the moment I saw the one O'Reillys had that looked almost totally identical to the stock one I bought it. It's a LOT louder than the stock pump was but the car seems to start quicker/easier and have a little better throttle response now than before so hopefully that'll do it. If not I'll start looking into the spark aspect next and go from there...

 

[project92camry]

yay! im glad to hear its running great