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Matt, Engineer
Category: RV
Satisfied Customers: 20361
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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I have an 84 VW camper with a Subaru EJ25 engine in it and

Customer Question

Hi there.
I have an 84 VW camper with a Subaru EJ25 engine in it and am having issues when at high speeds. I can be cruising and then I just loose power, step off the gas and a way we go again. My understanding it may be the Speed sensor. If this is true where would one find this?
Submitted: 4 months ago.
Category: RV
Expert:  Matt replied 4 months ago.


thats quite possible

the engine speed sensor is on the front of the engine, pointing at the crank pulley so its quite easy to replace , but you do have to remove the plastic belt cover

if its a 2 wire sensor type then you can measure its resistance to check it as it should be about 200-300 ohms

This could be a wiring issue as things tend to expand when hot and its possible a poor or partial electrical connection is being pushed apart on one of the major sensors so check the connection plug and wiring to the following;

Airflow meter

Crank position sensor

Cam position sensor

O2 sensor

Throttle position sensor

unplug each in turn and use some switch / contact cleaner spray on the pins to ensure its all grease / dirt free

Also worth checking the connections to the fuel pump for the same reason - unplug each in turn and give them a good squirt of switch / contact cleaner - Not WD40

and also unplug and inspect the main power relays and fuses for signs of overheating or corroded terminals - so the ones for the ECU and the fuel pump

And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.

Check the resistance of the spark plug leads ( 13-15Kohm / metre) and replace if any doubt or high resistance - Also replace the spark plugs if any of them fail this checklist:

Expert:  Matt replied 4 months ago.


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