Saturday, January 21, 2012

Lotus at BCCH tech day, hard starting diagnosed

I volunteered my Lotus for the January BCCH tech session. We met at the Boys Club on the 21st, which was perfect for me because Patrick works on his cars there. Patrick has just restored a Jag, but he also has three Europas under restoration. (See, I'm not so crazy!)

My main issue was the hard starting. Ever since I put the car back on the road it has been hard to start. When I turn the key the starter makes a lot of noise, but it is reluctant to catch.

My original cure was to replace the original starter with a geared down Denso, specially prepared for the Twin Cam. I got mine from Dave Bean. Still had the catch problem, but it cranked with a lot more authority.

Every once in a while I noticed another thing. The starter would not turn the engine over at all. The only sign of action was the pitch coming from the Holly fuel pump dropped a bit. Wait a bit and it would be back to normal.

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All this time I thought I had a bad ground or a faulty relay. Saturday's session revealed two things. First, the starter is being cooked by the exhaust pipe that runs directly under it, which causes it to stick. Once it cools, it comes back to life. I wrapped the starter in a heat shield for just this reason, but to do it right I need to fabricate one out of aluminum. Second, the teeth on the flywheel ring gear are hammered flat, making it difficult for the pinion to engage. The rattling sound is the pinion bouncing back and forth.

At this point I need to mention that lately the engine has been making a noise that sounds like a failing water pump. Could be the timing chain tensioner, but the water pump is much more likely. To fix that I will need to pull the engine and transmission, remove the head and oil pan.  (Did that back around 1979, just before the car went into the barn.) Time to restore the engine color back to the proper grey. New clutch and throw-out bearing. New timing chain. Install the new coolant pipes I bought a few years back. There goes my summer.

I want to thank all the guys from BCCH who participated in chasing after this daemon. Special thanks to Patrick, a wealth of knowledge. Good pizza, too.


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