Hey:
I have a modified 1969 Series IIA. Of course this is a manual transmission but has a newly rebuilt GM engine. I took my lady out yesterday to get her tires dusty and I noticed that she started jerking after being put in gear. This is true for any gear. It feels as if the engine gains and looses power. However, when I engage the clutch, the engine purrs normally, without a change in running speed. I have also noticed that it is getting harder to put her into 3rd and 4th gears. In those gears, I can sometimes beat the synchro mesh, but I usually hear some crunching when shifting to those 2 higher gears.
The jerking makes driving my lady almost impossible, but is better on pavement than on dirt roads; and we all know that the last thing any of these Rovers want is to be confined to hard surfaces. So, please help free my lady and I.
Thanks...Ben

 

Sounds like 2 problems, a tranny taking a **** and a GM engine running too lean. I doubt we can help much on the lean problem.
Mike

 

Mike:
Thanks for your response. A few more questions. Assuming its the tranny, should I replace the cylinders or do a clutch job? Second, what do you mean that the engine is running too lean? Is the idle too low? I was running her at 7,000 feel and manually adjusting the carb at several points. Once I was back in town at 5,000 feet the nightmare continued but only when there was a load on the engine (up a hill for example).
Thanks again...Ben

 

Hello,
Did you do any other upgrades or replacements when you installed the rebuilt GM Engine? You may need to check the ignition system for worn components. If you have a bad coil this may cause the trouble under load. This is due to the fact that when under load you have more fuel in the combustion chamber than you would have while idling. A bad coil would lead to insufficient or incomplete spark energy to support combustion. Check to see that your spark plug wires/leads are in good condition and that the distributor components are functioning properly. Your distributor control unit may need to be replaced if you see a strong spark which would indicate a operable coil. This is of course if you have upgraded the distributor to HEI or Unified "contactless" (no points) ignition. After all that is checked make sure that all of your wiring underhood is in good shape and not frayed causing a short to ground.
Good luck.

 

Thanks for the reply. The engine was put in with a brand new electronic ignition system. Over the last 4 months, I have replaced the entire electrical system, since a lot of the contacts and wires were shot. One additional thing, when I take her on the Highway, she runs nicely at 70mpg, and does not have any problems with jerking. It really only seems to set in on uphill or bumpy grades. To me it almost seems like that acceleration or bumps causes the gas petal to back off, causing the Landy to slow, allowing the accelerator to engage, forcing acceleration, etc... I tried to test this on a paved up hill, and although my foot was stable on the pedal, the jerking seemed to start slow and get incrementally worse.
Thanks again for everyone's help...Ben

 

I still think you have 2 problems, need to put that engine on a scope and have it checked. With the problems you have described with the tranny and 3rd. and 4th. gears, it is safey to say there are some problems going on there. As for the clutch, if you can dump the clutch under load and there is no slippage then I would not worry about the clutch, gotta be something with the engine.
Mike