W108 lack of power
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Joined: Jan 2022
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1967 W108 250SE
W108 lack of power
Hello
I just got a 1967 W108 250SE. i have changed all the hoses and pipes, filters, etc besides other structural things in the suspension. Still when revving the car seems to have a acouple (lack of power) at a certain RPM and then comes back again with power. I am sure the car is not performing as it should since my MGB that should be similar 0-100km/h that is restored is much faster then the W108 250se when both should be very similar.
the vehicle was my uncle that ride it once a month for the last 20 years. hasn´t been well maintained and i am now trying to restore it.
what are the most likely problems that originate this engine lack of power? is it the injectoin pump? should i refursbish it/restore it? i am from portugal, who can do it and where should i send it to? should i open the engine to do any cleaning and see if it has any problem? the ralenti is fine.
the vehicle was never restored in the past.
Thank you for your comments
Best regards
Antonio Matos
I just got a 1967 W108 250SE. i have changed all the hoses and pipes, filters, etc besides other structural things in the suspension. Still when revving the car seems to have a acouple (lack of power) at a certain RPM and then comes back again with power. I am sure the car is not performing as it should since my MGB that should be similar 0-100km/h that is restored is much faster then the W108 250se when both should be very similar.
the vehicle was my uncle that ride it once a month for the last 20 years. hasn´t been well maintained and i am now trying to restore it.
what are the most likely problems that originate this engine lack of power? is it the injectoin pump? should i refursbish it/restore it? i am from portugal, who can do it and where should i send it to? should i open the engine to do any cleaning and see if it has any problem? the ralenti is fine.
the vehicle was never restored in the past.
Thank you for your comments
Best regards
Antonio Matos
Thread Starter
Newbie
Joined: Jan 2022
Posts: 2
Likes: 0
1967 W108 250SE
Hello, no, i still have the problem. but i haven´t tried to solve it yet. i need to take it to a garage to try to fix it. I´ll post the solution once i find it.
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Joined: Apr 2022
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W108
Power loss diagnostic
Ok...here is the long list of diagnostics I am about to assess....
I have a w108 with same issue....bought a month ago
When and where did you get yours ?
See below
According to discussion groups, engine power loss after 20mins of driving is common for w108. It happens after hitting certain rpms when the engine is hot. The following is a list of potential causes under the 3 main root causes: 1. Compression issues 2. Fuel issues 3. Spark timing issues Issues referenced are shown below. Compression: 1. Remove gas cap to check pressure...test for swoosh 2. Vapour lock 3. Valves too tight 4. Use Compression test tool 5. Pressure in main engine 6. Adjust valves / intakes 7. Sensors...bad thermo time switch or warm up compensator 8. Solenoids Fuel: 1. Rusty tank and lines 2. Both fuel filters 3. Filter strainer in fuel tank (ie Air in fuel line) 4. Mechanical fuel pump wear out 5. Inline fuel filter under bonnet change 6. Blocked return valve I'm gas tank 7. Other?: egr valve, maf sensor Spark timing: 1. Use ignition analyser(sun scope) 2. Timing light 3. Electronic ignition box (that boosts voltage) faulty when hot 4. Tarnished connection in ignition module 5. Pull coil wire out of distributor and look for blue powder (means coil wire is arcing) 6. Worn rotor arm 7. Cracked distributor cap
I have a w108 with same issue....bought a month ago
When and where did you get yours ?
See below
According to discussion groups, engine power loss after 20mins of driving is common for w108. It happens after hitting certain rpms when the engine is hot. The following is a list of potential causes under the 3 main root causes: 1. Compression issues 2. Fuel issues 3. Spark timing issues Issues referenced are shown below. Compression: 1. Remove gas cap to check pressure...test for swoosh 2. Vapour lock 3. Valves too tight 4. Use Compression test tool 5. Pressure in main engine 6. Adjust valves / intakes 7. Sensors...bad thermo time switch or warm up compensator 8. Solenoids Fuel: 1. Rusty tank and lines 2. Both fuel filters 3. Filter strainer in fuel tank (ie Air in fuel line) 4. Mechanical fuel pump wear out 5. Inline fuel filter under bonnet change 6. Blocked return valve I'm gas tank 7. Other?: egr valve, maf sensor Spark timing: 1. Use ignition analyser(sun scope) 2. Timing light 3. Electronic ignition box (that boosts voltage) faulty when hot 4. Tarnished connection in ignition module 5. Pull coil wire out of distributor and look for blue powder (means coil wire is arcing) 6. Worn rotor arm 7. Cracked distributor cap
