• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

Strange problem with throttle staying open

bighealeysource

Jedi Knight
Country flag
Offline
Hey y'all,
Haven't posted for a while, been reading posts, but can't believe it has been so long since I posted. Anyway, got an unusual problem.

The throttle on my 100M has been sticking open occasionally and got me stumped. Not all the time, could be cold engine or hot engine. Go to shift and engine revs stay up, not high enough to damage anything but not right. It will return slowly by itself so doesn't remain stuck open.

Checked to make sure it wasn't something very simple like gas pedal hanging up on the carpet or the pedal was sticking at the small shaft it pivots on. Everything okay there. Checked all the throttle linkage and nothing sticking there, spring on throttle shaft not sticking, and return spring connected and still "springs" okay. Linkage is relatively stiff but always has been. Checked the carbs, cleaned up the pistons, checked oil level in damper assembly. Even ordered new springs for the pistons/chamber assemblies but those are not in yet as just ordered. Hoping, that might be it but any ideas ???

Thanks,
Mike:confusion:
 
Country flag
Offline
... ordered new springs for the pistons/chamber assemblies but those are not in yet as just ordered. Hoping, that might be it but any ideas ???

Doubt that's the cause of the problem; this sounds like the throttle plates are being held slightly open for some reason. Suspect something is binding; either in the carb-to-carb linkage or in the throttle linkage. Just reworked the throttle mechanism on my BJ8; it's possible, if the linkage isn't adjusted correctly, for the the linkage to bind up in an 'over center' position (but not particularly likely). If I had to guess, there's gunk or a worn bushing(s) in the throttle shafts. I have a BN2/100M as well, and never felt the coaxial return springs did a good job of returning the throttles to closed; when I let off the gas pedal, sometimes the RPMs will drop to an above-idle speed, then gradually slow down.
 
Country flag
Offline
How's the throttle shaft to bore fit? If the shafts are worn, they could allow enough misalignment for the plates to get slightly cocked in the throats, dragging to the closed position.

That's something you can check when you open them up to replace the damper springs.
 
OP
bighealeysource

bighealeysource

Jedi Knight
Country flag
Offline
Thanks Randy and Bob - I'll let you know after I replace the damper springs as well as main return spring if it solves the problem or do I need to look into your suggestions. Don't think it is gunked up as have sprayed enough carb cleaner on the linkage to qualify for an EPA superfund site !
 
OP
bighealeysource

bighealeysource

Jedi Knight
Country flag
Offline
Well y'all,got new damper springs and a new return spring and has helped but still seems to stick sometimes. Not as bad but suspect it's a combo between what Randy and Bob have said. Guess next step is to take the cold air box off AGAIN, and double check all the linkage and see if it is binding somewhere. Will let you know what solves it.
 
Similar threads
Thread starter Title Forum Replies Date
7 Strange A/C - radio problem Other Cars 7
J Strange electric problem. Jaguar 11
58Custom Sudden, strange problem with tach. Spridgets 2
F Strange Turn Signal Problem... MG 12
Steve P. strange smoothcase shifting problem solved.... Spridgets 1
S another strange problem Triumph 11
Bret Strange problem? MG 16
Vargus TR2/3/3A Strange dents Triumph 19
nicko Strange Engine Noise Austin Healey 7
jlaird MGB Strange daily question. MG 10
C MGB strange?? MG 3
J TR2/3/3A such strange thread on gear shift knob Triumph 12
S TR2/3/3A Strange part Triumph 3
steveg Strange gasket pieces Austin Healey 5
steveg Strange Oil Leak Austin Healey 7
D TR2/3/3A Strange hole! Triumph 5
SherpaPilot Strange Noise While Cornering in TR6 Racing 3
Jim_Gruber Strange noises - Bad U Joint perhaps? Spridgets 10
Michael Oritt Strange debris found in sump Austin Healey 19
F TR2/3/3A Strange Loud Noise Triumph 11
C Strange...can won't start and then magically ressurects Austin Healey 16
D TR2/3/3A Strange Transmission Issue Triumph 9
Rhodyspit75 Strange windshield washers Spridgets 0
tahoe healey strange OD question. Austin Healey 9
andrea Very strange austin healey 3.9 Austin Healey 5
M Strange Healey Tach Austin Healey 9
Rut Strange occurance! Spridgets 19
aeronca65t Big Healey-strange wheels Austin Healey 12
bighealeysource Okay, here's one with a strange noise from the engine Austin Healey 7
J TR2/3/3A Strange fiberboard panel behind rear seat in TR3 Triumph 10
J TR4/4A Strange question that may involve the coil- Triumph 13
jlaird Todays strange question Spridgets 6
JPSmit What is that strange grinding sound in the distance? Spridgets 3
PAUL161 MGB Strange Reminder of a Missing Friend. MG 4
B Strange rear light Other British Cars 6
KVH Strange Sound Like Compressed Air Escaping Triumph 14
Bremer TR2/3/3A TR3A: Strange brake bleeding behaviour Triumph 4
B SU Carbs have strange vacuum fitting Triumph 17
Kleykamp TR2/3/3A Strange TR3 side curtains ??? Triumph 13
HAN8L1965 Strange event ? Spridgets 6
T strange litter Triumph 5
aeronca65t Strange and interesting MGs MG 3
PAUL161 Strange 5 Speed Conversion - Will it Work? MG 41
W Strange occurence Spridgets 5
P Strange clunking noise Triumph 20
bugedd Strange trans noise Spridgets 7
Musicman Strange Clicky/Tappy Sound Triumph 6
SilentUnicorn Strange things British Motorbikes 4
Bremer Strange, but interesting... factory blunders? Triumph 8
M another strange bugeye on ebay Spridgets 12

Similar threads

Top