Shake down...!

Well it's been ages since I've posted... and the more I've left it the longer it's taken me to get back to it but here I am with some updates.

I got the car back from Darrin with a few home truths that I didn't really want to hear but had to.. the chassis wasn't as solid as I had hoped...! Besides the items I was aware of Darrin informed me that one of the sills needed work and he also recommended the other get's done too as they usually both go, so time to sell my Datsun 240Z to fund the restoration.

This brings home the importance of taking off the outer decorative sills as found on the Pallas models to really see how things are, disappointing yes, but I don't regret it as I would have still bought her regardless.

Now as far as enjoying the car in the Summer, Celia had other plans. I had one local run with the family but teething problems here and there; starter motor failed and a leaking injector, put an end to any further fun in the sun.

These inconveniences were rectified but another malady occurred this time a lean misfire which got progressively worse to the point of making the car un-driveable. Old cars which have not run in years often take time to settle down, this "shake down" period is often the time that the car reveals any inherent problems.

On the whole misfires are mainly down to two systems not operating correctly either, fuel or ignition or sometimes both. The factory service manual (FSM) is invaluable at helping to track down problems and the Repair Manual 814 Volume 1 is a must have, donwload it from Tony Jackson's drop box here: Dropbox

After a variety of testing, swapping coils, spark plugs, distributors etc.. the problem still persisted. Not wishing to be beaten, I even purchased a Bosch D Jetronic tester to get to the bottom of it as I suspected it was the early D Jetronic fuel injection system at fault. Whilst I didn't carry all the test out as laid out in the FSM it passed the ones I did try.

Before

After

One of the points the FSM states prior to commencing the tests on the fuel injection system is to ensure that the main earthing points are in good shape, mine being original and a little frayed it was important to change. So I replaced the earthing strap which goes from the battery to the water pump which also includes the earth for the fuel injector loom and since the original strap is fairly thin I decided to replace it with  a thicker cable for good measure.

Despite my best efforts the misfire persisted and  Darrin was able to take a look and get to the bottom of it. The issue was a powdery residue was blocking the fuel injectors.  Being the inexperienced mechanic that I am (read not a mechanic) I ruled dirty injectors out, since they were new, fuel filter was new, fuel tank was new and so too were the rubber fuel lines. The cause; a dirty fuel rail.

Now this has been fixed she is running well and some tweaking of the clutch release mechanism has made her a joy to drive, if you've not tried the BVH please try to, it is worth experiencing being a joy to use when it's set up right.

One thing I did notice that I will need to keep an eye on is a hesitation; when sitting at 70mph on the motorway in 4th gear the revs dropped from around 3,000rpm to 2000rpm and then recovered, this blip has happened more then a few occasions now and I am hoping it will go away but I suspect not... will update once I've discovered any more. If you've got any ideas what could be causing this please let me know.