Anyone else having repeated throttle body failures? - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Eaton PSI · 11-14-2025, 09:50 PM

I had a throttle body fail in january of this year. Yesterday the new one started to glitch just like the old one.

Erratic idle and cruise, and engine revs increasing to 2k-3k when pushing the clutch in with no input on throttle pedal. Cycling the throttle with the engine off, it sounds squeaky and unhappy.

The car has a harrop supercharger and the throttle body is rotated 90deg (black plastic cover faces upwards).

The last one behaved like this intermittently for a few weeks before I finally got stuck in limp mode.

Anyone else having throttle body issues?

ArCha · Yesterday, 12:01 AM

I've had similar, also on a Harrop. A few months ago I got stuck in limp mode as well, very annoying since there was no code until then. We noticed a voltage change when jiggling the jumper harness to the throttle but pulling the harness and doing a continuity check revealed no issues and we couldn't repeat the finding after we'd reassembled either. Tried cleaning the throttle body and MAF, no change.

We ended up swapping one of the relays and that seems to have resolved everything but I don't drive the car very often to be definitive. This was the same day as trying some of the other fixes. Just turned off the car, swapped a relay and when it turned back on the problem was gone.

Eaton PSI · Yesterday, 03:37 AM

Yes, same here. No codes, just odd behaviour until it eventually goes into limp mode. Fortunately I keep an OBD dongle in the car so I was able to reset it and get home.
Some days it does it on the way home from work. It will start up fine in the morning and not glitch for another week.
I pulled an old throttle body apart and checked the motor on 12v. It sounds ok when horizontal but a bit odd in the vertical position. I wonder if the harrop throttle body relocation causes issues.
The gears were all completely dry, no trace of grease or anything. The shaft for the little idler gear actually had a tiny bit of rust on it.

Muskoka800 · Yesterday, 01:00 PM

Sounds like a Harrop problem.
I have had zero such issues running Edelbrock for several years now.
Perhaps Harrop have a solution???

Eaton PSI · Yesterday, 07:39 PM

Is the throttle body rotated on the edelbrock?

Muskoka800 · Today, 11:57 AM

I’m thinking no but can confirm later today. The alternator was the only component I recall needing re-orientation during the kits install. The kit did include new, longer hoses for the TB coolant supply/return.

11-14-2025, 09:50 PM	#1
Eaton PSI Member Join Date: Mar 2023 Drives: 2013 86 Location: melbourne VIC Posts: 71 Thanks: 3 Thanked 42 Times in 24 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Anyone else having repeated throttle body failures? I had a throttle body fail in january of this year. Yesterday the new one started to glitch just like the old one. Erratic idle and cruise, and engine revs increasing to 2k-3k when pushing the clutch in with no input on throttle pedal. Cycling the throttle with the engine off, it sounds squeaky and unhappy. The car has a harrop supercharger and the throttle body is rotated 90deg (black plastic cover faces upwards). The last one behaved like this intermittently for a few weeks before I finally got stuck in limp mode. Anyone else having throttle body issues? __________________ 2014 GT86, 2.2L big bore, harrop supercharged

Yesterday, 03:37 AM	#3
Eaton PSI Member Join Date: Mar 2023 Drives: 2013 86 Location: melbourne VIC Posts: 71 Thanks: 3 Thanked 42 Times in 24 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Yes, same here. No codes, just odd behaviour until it eventually goes into limp mode. Fortunately I keep an OBD dongle in the car so I was able to reset it and get home. Some days it does it on the way home from work. It will start up fine in the morning and not glitch for another week. I pulled an old throttle body apart and checked the motor on 12v. It sounds ok when horizontal but a bit odd in the vertical position. I wonder if the harrop throttle body relocation causes issues. The gears were all completely dry, no trace of grease or anything. The shaft for the little idler gear actually had a tiny bit of rust on it. __________________ 2014 GT86, 2.2L big bore, harrop supercharged

Yesterday, 01:00 PM	#4
Muskoka800 Senior Member Join Date: Jul 2018 Drives: 2016 Scion FRS Release Series 2#439 Location: Chatham, Ontario, Canada Posts: 769 Thanks: 4 Thanked 168 Times in 138 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	Sounds like a Harrop problem. I have had zero such issues running Edelbrock for several years now. Perhaps Harrop have a solution??? __________________ Edelbrock S/C with CSG 94 & 91 maps TRD Short Shifter, CTS-V/EvoX Brembos Ohlin’s R&T Dampers, Hotchkis F/R Bars, Blox LCA & Toe Arms 235F/245R Conti ECS on TRD/Enkei wheels (street), 245/40 sq. ECF on 17x8 720Form GTF2 wheels (track)

Yesterday, 07:39 PM	#5
Eaton PSI Member Join Date: Mar 2023 Drives: 2013 86 Location: melbourne VIC Posts: 71 Thanks: 3 Thanked 42 Times in 24 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Is the throttle body rotated on the edelbrock? __________________ 2014 GT86, 2.2L big bore, harrop supercharged

Today, 11:57 AM	#6
Muskoka800 Senior Member Join Date: Jul 2018 Drives: 2016 Scion FRS Release Series 2#439 Location: Chatham, Ontario, Canada Posts: 769 Thanks: 4 Thanked 168 Times in 138 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	I’m thinking no but can confirm later today. The alternator was the only component I recall needing re-orientation during the kits install. The kit did include new, longer hoses for the TB coolant supply/return. __________________ Edelbrock S/C with CSG 94 & 91 maps TRD Short Shifter, CTS-V/EvoX Brembos Ohlin’s R&T Dampers, Hotchkis F/R Bars, Blox LCA & Toe Arms 235F/245R Conti ECS on TRD/Enkei wheels (street), 245/40 sq. ECF on 17x8 720Form GTF2 wheels (track)

Yesterday, 12:01 AM	#2
ArCha Member Join Date: May 2014 Drives: 2013 Subaru BRZ SWP Location: GTA - Canada Posts: 28 Thanks: 4 Thanked 16 Times in 13 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	I've had similar, also on a Harrop. A few months ago I got stuck in limp mode as well, very annoying since there was no code until then. We noticed a voltage change when jiggling the jumper harness to the throttle but pulling the harness and doing a continuity check revealed no issues and we couldn't repeat the finding after we'd reassembled either. Tried cleaning the throttle body and MAF, no change. We ended up swapping one of the relays and that seems to have resolved everything but I don't drive the car very often to be definitive. This was the same day as trying some of the other fixes. Just turned off the car, swapped a relay and when it turned back on the problem was gone.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Major accident/Engine failure after repeated P0351/P0017/P0019	DB86	Issues \| Warranty \| Recalls / TSB	48	09-16-2014 04:05 PM
Anyone having throttle issues?	FRiSson	Issues \| Warranty \| Recalls / TSB	13	09-25-2012 06:35 PM
Anyone else having bluetooth problems?	Scooter Style	Electronics \| Audio \| NAV \| Infotainment	8	08-03-2012 07:38 PM
Anyone else having trouble finding an alignment place?	track_warrior	Suspension \| Chassis \| Brakes -- Sponsored by 949 Racing	4	07-30-2012 12:26 AM

User Name		Remember Me?
Password