pacerman

1998 ES 300 3.0 V6 100k miles plus. Starts and idles fine, warms up 10 minutes or so, and steadily the max rpm's drop to no more than about 3000 or so before it starts sounding like it hits the rev limiter. before the warm up, it tachs out above 6000 with no limiter sound. Nice and smooth. Got my Genisys after it, and a 2001 ES 300 to compare. Only thing I saw really different was the vapor pressure. 2001 had it .19, while the 1998 had it at 137.00 plus. I do not have any codes, pending or hard ones, To my question: Would the charcoal canister being plugged cause this, or possibly the vapor pressure switch? Any direction at all would be very helpful. Thanks in advance.

nsghtbrwry

I'm not familiar with what the numbers should be, but a malfunctioning EVAP system wouldn't cause it to do the rev limiting thing. After it warms up, maybe have a helper see if the throttle is opening fully?

pacerman

Thank you for the reply, nsghtbrwry. Throttle was cleaned and checked. Fully operational. TPS functions within specs. Only does it after the warm up. Vapor specs start out at abot 135.00 and only go up. I pull the fuel cap off, and it goes back down to around 135.00 or so.

nsghtbrwry

Can you post some screenshots of other live data parameters?

pacerman

I'll get some at work today, and have them after 5 tonight. Any in particular?

nsghtbrwry

Nah, just want to see what else - if anything - looks out of place. I can't see how a malfunctioning EVAP (if it is malfunctioning) can cause what you described

pacerman

Seeing as to how I havent met the minimum criteria, the forum won't let me post pics just yet. Any numbers you need, let me know, and I'll post them. Thanks.

nsghtbrwry

Well, I was thinking because somebody has a similar problem on the Toyota Nation gen3/4 forums - 4cyl Camry is dying at 2500 RPM after warmup. I thought it might be an EGR problem.

Does your car do this if you stomp on the gas, go WOT? EGR shouldn't be operating during warmup or WOT, and your '98 1MZ shouldn't be VVT so should still have dedicated EGR hardware

nsghtbrwry

Oh, and if you can post what short term and long term fuel trims are like at different RPMs while you're driving. I'm wondering if this could be a MAF sensor issue. I haven't had one go entirely bad, but I replaced one on a '99 - no codes, but it was overfueling outside of WOT because of a bad signal from the MAF.

pacerman

At WOT, until it warms up, it goes upwards of 6k rpm. Steady decline the warmer it gets. MAF reading starts out at 3.4, and goesup with throttle to just over 13. LTFT B1 goes up from 0.00 at key on not running, to -5.6 under throttle. LTFT B2 stays down around 0.00 to -2.something.STFT B1 in the negatives, along with STFT B2 being the same. Not the same numbers, but kinda close. Running LTFT on both banks stays at 1.00.

nsghtbrwry

Hm, nothing out of place there. Any work done to the car recently? I'm out of ideas

pacerman

Judging by what I can see, a lot. I cleaned the TB, before we got it, someone Changed the plugs, and it has a reman Toyota ECU in it. Looks like someone went through it searching, and not finding. We got it from an auction. Honestly, the only thing I see different from the 01 we have, is the vapor pressure. With it being so high, would that make the ECU thin out the fuel flow? After it warms, it starts missing consistently on cyl 2,3, 5 and 6. I swapped 2 injectors, and 2 coils and 2 plugs. Nothing changed. Starting to think it's a gremlin. Lol.

nsghtbrwry

Hm, I know you're hurtin' right now about this car but I love threads like this, with weird problems to fix

Well, you can try taking the EVAP out of the system - disconnect it from the throttle body/intake hose and plug those for a bit. Those cylinders are weird...did it throw codes on those, or does your scanner somehow have a misfire counter (My Actron has misfire counting on GM vehicles, but not on Toyotas)? Guess you can start verifying the usual on those cylinders: spark, fuel, air, compression.

pacerman

My diagnostics does have a misfire monitor, and it only does it after the warm up, when it starts to bog. No other time. That's why I was wondering if the ECU is seeing too much vapor pressure, and is telling the fuel system to lean it out to the point of misfiring. It doesn't show misfire under the CEL, pending or otherwise, only under the monitor. Here's a brain fart. Possibly a 2 part problem? Fuel pump getting weak after running for a few minutes, along with a bad vapor switch? Thoughts?

nsghtbrwry

Take the vapor switch out of the equation by disconnecting all EVAP lines from the throttle body and air intake. Yeah, I'd check fuel pressure after it's warmed up...coils could be screwing up as well once they get warm. I do think coils are more likely than the fuel pump. Of course, since you're not throwing codes, it could be a wonky ECU (not sure if you can just swap those like on the contemporary Camrys, or if you have to program them due to security computer).

I did a write-up a while back on TN for retrofitting a Schrader valve to the Camry I4, you could do the same on these so you don't have to use a fancy inline fuel pressure gauge: http://www.toyotanation.com/forum/10...-retrofit.html

...one guy did ask about doing it at the fuel rail for the 1MZ since it's more accessible than the fuel filter which is way down low.