Lesson learned ... these cars do NOT like low octane gas

[meadowz06]

Originally Posted by Razz

Really?

You haven't got a clue how a car works.

Ditto!

[Tromatic]

Mine ran fine on a tank of 87 octane. Sweet guarantee that dealer has. By an FR-S, beat the shit out of it for 48 hours and bring it back. Note to Self: Self, never buy a car from that dealer. For sure no low-mileage used FR-S's.

[SillySaxon]

The ticking is the HPFP. It's hi pressure and it is really noisy. It's the same in all HPFP cars. It even says this in the manual.

Crickets sound like a squeaky belt, they are from bad design HPFP seals and we are all waiting the glorious day when they stop forever

[chrisl]

Originally Posted by SillySaxon

Crickets sound like a squeaky belt, they are from bad design HPFP seals and we are all waiting the glorious day when they stop forever

The crickets are not related to the injector seals. At all. The injector seal issue had to do with detonation with an older ECU tune under specific, high-RPM conditions.

(Didn't you already get corrected after posting this misinformation in a different thread?)

[SillySaxon]

Originally Posted by chrisl

The crickets are not related to the injector seals. At all. The injector seal issue had to do with detonation with an older ECU tune under specific, high-RPM conditions.

(Didn't you already get corrected after posting this misinformation in a different thread?)

Didn't say DI seal, hpfp seal.
Read

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[sumo junkie]

Originally Posted by wbradley

Don't worry the ECU pulls the timing instantly with knock detection. The only real negative is reduced volumetric efficiency (power). No damage done.

If you return the car you deserve a Veloster! LOL

I tend to believe that the 86 engineers that everyone worships would have thought of what to do if someone puts low octane gas in the car

[PStaff716]

my friend was the salesman that hooked me up with my frs, he told me (weeks afterwards) that they put 87 octane in my car. He didn't know at the time, but a coworker of his informed him later on.

As soon as I put 93 in I was like "woah, this thing feels smoother and a little more responsive"..I told myself I was just an idiot and it was nothing. I guess I was right after all..

btw, I never really felt the 87 was a problem when I was driving it, I just noticed that the first 93 fill-up felt like I had tweaked a tune or something. It was just a tad bit quicker IMO

[chrisl]

Originally Posted by SillySaxon

Didn't say DI seal, hpfp seal.
Read

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And where is your evidence for this? I haven't heard anyone else claiming this to be the case.

[SillySaxon]

Originally Posted by chrisl

And where is your evidence for this? I haven't heard anyone else claiming this to be the case.

All the posts on it are about the plunger seal and washer. Just search

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[Asinar]

Originally Posted by wbradley

Don't worry the ECU pulls the timing instantly with knock detection. The only real negative is reduced volumetric efficiency (power). No damage done.

I'd still be a little concerned about low octane if you were driving it hard (which you shouldn't be doing the first 1000 miles). The DI seal problem is ostensibly due to detonation from failure to properly retard ignition and excessive reliance on knock detection. That problem would be amplified with low-octane fuel and there is no guarantee the ECU mappings retard timing sufficiently for crap fuel. This is hypochondriac-level fretting so I wouldn't lose sleep over it but would take them up on the offer for a new new car.

My FR-S was a 500-mile demo car so Lord only knows what they did with (or put into) it but it seems to have staved off the cricket infestation. (Pressing my luck every time I say that.)


Now, I do have a technical question regarding knock sensors and ignition timing. My engine knowledge is primarily limited to airplanes (which is comparable to 1960's car technology) but I do know enough about control theory to be dangerous. I assume the engine detunes itself to maintain a specific (but finite) rate/level of knock (e.g. PID) not merely retard itself some arbitrary amount on first sign of knock. Does anyone know what the algorithms actually look like?

[wbradley]

Originally Posted by Asinar

I'd still be a little concerned about low octane if you were driving it hard (which you shouldn't be doing the first 1000 miles). The DI seal problem is ostensibly due to detonation from failure to properly retard ignition and excessive reliance on knock detection. That problem would be amplified with low-octane fuel and there is no guarantee the ECU mappings retard timing sufficiently for crap fuel. This is hypochondriac-level fretting so I wouldn't lose sleep over it but would take them up on the offer for a new new car.

My FR-S was a 500-mile demo car so Lord only knows what they did with (or put into) it but it seems to have staved off the cricket infestation. (Pressing my luck every time I say that.)



Now, I do have a technical question regarding knock sensors and ignition timing. My engine knowledge is primarily limited to airplanes (which is comparable to 1960's car technology) but I do know enough about control theory to be dangerous. I assume the engine detunes itself to maintain a specific (but finite) rate/level of knock (e.g. PID) not merely retard itself some arbitrary amount on first sign of knock. Does anyone know what the algorithms actually look like?

I read somewhere that knock is detected audibly (there is a sensor somewhere in the engine bay). This ECU uses considerable timing advance as the RPMs rise. Only reason I know this is that I have a timing advance gauge in Torque running on my dash mounted Nexus 7 tablet. For example, at idle the advance might be 11 degrees before top centre crank position and at 3500 RPMs it might be closer to 38 or 40. I would think the sensor would continue to retard timing until knock is supressed on a feedback loop. This way performance wont be totally ruined at 91 octane by retarding the same as if it was 87.

[stugray]

My engine knowledge is primarily limited to airplanes (which is comparable to 1960's car technology)

I have similar experience with air-cooled 4-cyl boxer engines, and I wonder if this engine has the ability to "pre-detonate" or diesel.
The air cooled engines could diesel if they got hot enough.
If this occurs, the timing retard does absolutely nothing since the detonation occurs before the spark even goes off.
In those engines, above ~10:1 requires high octane or very close monitor of head temps (350F is not unheard of...)

[rskdsk]

Well ... car is now on its way back to toyota and I have a brand new series 10 (I paid an extra 1500). I was backing out of the driveway today and the car stalled ... last straw. I gave the car back with just over 500 miles on it and the only other AT at the dealership was a series 10. The color is not my first choice ... but the extra equipment sold me.

[SillySaxon]

Originally Posted by rskdsk

Well ... car is now on its way back to toyota and I have a brand new series 10 (I paid an extra 1500). I was backing out of the driveway today and the car stalled ... last straw. I gave the car back with just over 500 miles on it and the only other AT at the dealership was a series 10. The color is not my first choice ... but the extra equipment sold me.

Be warned you can still stall in reverse with an ok engine, high gear ratio and it likes to bog if you let off too much clutch

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