Jump to content
Click here if you are having website access problems ×

Crossflow Engine Earthing


TANGO7

Recommended Posts

Following on from my Post "Battery Recommendations" all components and connections have been checked and all deemed OK but the problem of  "lethargic" cranking still continues.

I am wondering if I have an earthing problem. The -ve from the battery is earthed direct to a bolt on the bellhousing and the starter motor obviously earths direct on the block. I can find no other relevant earth straps. Is there supposed to be an earth cable from the engine block to the chassis? (I remember on a previous crossflow I had there was another earth cable. I seem to recall it ran from the block/bellhousing to the brake master cylinder mounting bracket - but I may be mistaken on its location).

Any thoughts on the need for such an earth strap and, if so, its location?

Link to comment
Share on other sites

Thanks for the comments. I have located the earth strap from the block to the engine mounting bolt. Removed and all surfaces cleaned. This has improved things, so definitely worthwhile. However, the engine still doesn't crank as fast as I would like. Perhaps I am being too unrealistic in my aspirations.

Link to comment
Share on other sites

Thanks for the comments. I have located the earth strap from the block to the engine mounting bolt. Removed and all surfaces cleaned. This has improved things, so definitely worthwhile. However, the engine still doesn't crank as fast as I would like. Perhaps I am being too unrealistic in my aspirations.

Link to comment
Share on other sites

Thanks for the comments. I have located the earth strap from the block to the engine mounting bolt. Removed and all surfaces cleaned. This has improved things, so definitely worthwhile. However, the engine still doesn't crank as fast as I would like. Perhaps I am being too unrealistic in my aspirations.

Link to comment
Share on other sites

I wouldn't have thought so either but definitely a phenomenon on my mini. The only logic I could come up with was it fired too early while the piston was still rising / compressing and the 'ignite' worked against this almost trying to make the crank go backwards.

When jump starting what happens if you attach the earth jump lead directly to the engine? You can also put the +ve jump lead directly to the starter but you have to be extremely careful.

There is only so many things it can be - faulty cable or component causing a high resistance / poor connection and its a case of substituting one by one.

I've also read of components being tested as good by experts but have later shown to be faulty.

Regards

Ian

Link to comment
Share on other sites

Maybe best to take the starter off and clean the rotor and carbon with brake clean, if it still cranck slow invest in a Lucar LRS110 1.4kw much cheaper than all those special starters and just as good https://www.ebay.co.uk/itm/2-0-FORD-PINTO-LIGHTWEIGHT-UPRATED-STARTER-MOTOR-LRS00543-LRS00109-LRS00110/273796747058?hash=item3fbf8ecf32:g:a~YAAOSw8

Link to comment
Share on other sites

Thanks to all. I will bear in mind the starter motor suggested in #17/18. Perhaps even tho the starter motor on the car has been deemed ok one with more power would obviously help. Is the one suggested a pre engaged type as mine is inertia type?

Link to comment
Share on other sites

Yes the LRS110 is pre engaged, the inertial type can't match the performance of the new breed of starters, give your starter a good clean and see what that gives. To swap to an pre engaged system can be done on a budget with new starter and ring gear or expensive with new light flywheel, clutch assembly and starter motor.

Link to comment
Share on other sites

Starter removed and stripped. All looked OK, no obvious problems and clean. However, during removal, I noted the securing bolts were not as tight as I would have thought they would be. On removing the starter, I noticed the face of the flange of the motor and the mounting face on the bellhousing were covered with a fine film of oil. Both faces were cleaned with meths, the starter replaced and bolts tightened up satisfactorily. On starting a vast improvement in cranking speed over previous. I can only assume the starter motor earths to the engine through its mounting on the bellhousing and this was  compromised by slack mounting and oil on the flange faces

Link to comment
Share on other sites

One cable between the starter and solenoid. (+ve feed)

The solenoid has the above cable to the starter, a cable to the battery +ve terminal and a wire which disappears into the wiring loom (presumably to the ignition switch). 

There is a single wiring block connected to the alternator with all wires going directly into the loom. I presumed the alternator earthed through its mounting bracket and bolts direct to the engine block.   

 

 

 

 

 

 

 

 

 

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...