1992 Suzuki Samurai Engine throttle issues

AEHSSANI

MEMBER
1992 SUZUKI SAMURAI
4 CYL
4WD
MANUAL
130,000 MILES

Hi, My car has developed a peculiar problem, when I turn on my parking and or headlights, my engine's RPMs increase to about 3,500 and stay there until I turn off the lights. This occurs regardless of engine speed/gear, driving or if I am at a stand still. All the fuses are good and I don't see an obvious short anywhere in the wires. I live in the Caribbean and no one around here seems to be able to diagnose this. To make matters worse, I think the increased RPMs are contributing to an overheating problem and have led to a water pump gasket leak. What do you think about the light/throttle issue? Also, can I get away with replacing the water pump gasket since a new pump is about 150 dollars here? Thank you in advance

1 Reply

KHLOW2008

MECHANIC
41,815 POSTS

Hi aehssani,

Thank you for the donation.

Additional air going into the intake manifold would increase the idling speed. There are 2 possibilities for this happening.

1. Idle Solenoid Control valve is receiving a signal to open allowing more air to go in.
2. Throttle is being operated by the Throttle Opener Vacumn Switching Valve. Item # 14 in diagram.
I would suspect this to be the problem. Check if the VSV is being activated when lights are turned on with engine running.

Throttle Opener VSV is activated by the ECM so this could be bad news.

If the water pump gasket is leaking, replacing it would do but if the water pump is leaking, no other option but to replace it.