Bj70: occasionally remains accelerated (2 Viewers)

[Lorenzoesse]

Hello everyone, sometimes my Bj70 (3b engine - 1985) remains accelerated, it doesn't happen often when cold, it happens more times when hot... I've already checked the accelerator cable, it's in place, it seems to flow well, new pump diaphragm, new injectors... I can't figure it out, it happens more if you pull 1st, 2nd or 3rd gear, with 4th and 5th it happens much less.
Does anyone know where I could look? the engine even when hot has no problems on idling and goes, but when you release the accelerator you have this problem..
Thank you!

 

[coldtaco]

I would assume that there is at least one spring in the throttle pedal/cable assembly or at the engine. Maybe these are tired and have lost their original tension

 

[duncanrm]

Check that the hose clamp on the throttle body side of the crankcase ventilation hose isnt fouling the butterfly mechanism..

 

[Felde]

Depending on the IP you have, acceleration is managed by a butterfly valve at the intake manifold and two vakuum hoses going to the IP. The butterfly is spring loaded.
Check for smooth operation, sufficient spring load and the vakuum hoses being OK and connections are not leaking.
You said your diaphragm is new?
If 'accelerated' means, it runs 'normal, at higher revs', just at a time it shouldn't, the culprit must be in this area. If it is the guts of the IP, there likely is an imbalance of fuel and air making it running not normal, iIl guess.
Good Luck Ralf

 

[Lorenzoesse]

ok ragazzi ho risolto Ho sentito da un vecchio meccanico (ha rifatto il mio 3b che era completamente pieno di morchia e intasato), mi ha consigliato di guardare bene questo regolatore e di svitarlo un po'... aveva ragione, ecco.. io lo farei non ci avevo mai pensato... praticamente la manetta restava leggermente aperta e quindi non tornava dopo aver accelerato... problema risolto!

grazie a tutti ragazzi

 

[Felde]

Thank you for sharing.
That's the setting screw for the idling revolutions and the mechanism for the butterfly. I read your comment via Google translate. If I interpret it correctly, your mechanic recommends to disassemble, clean and lubricate that unit, in order to make sure it smoothly returns and doesn't get stuck.
Makes sense!
But you will need to set the right idle setting again.
Good Luck Ralf