Eddie_V8 Posted May 10, 2020 Share Posted May 10, 2020 (edited) Hi all, I'm currently going through a megasquirt build on my 110, changing the cracked 3.9 to a 4.0 GEMS. I've got as far as getting her started but the timing is not right. I had thought I had got it close before I bolted everything together but it's very lumpy running, backfiring etc. When I set TDC I used #1 and the rocker cover off, spun the engine waiting for both valves to fully close etc. My question is is there a more accurate way of timing the 4.0 as there are no pulley marks (cheers landrover). Any help much appreciated. Ed Edited May 10, 2020 by Eddie_V8 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted May 10, 2020 Share Posted May 10, 2020 Here you go: Bear in mind you may have your leads in the wrong place, it is the #1 most common fault with backfiring and lumpy running. Quote Link to comment Share on other sites More sharing options...
Puffernutter Posted May 10, 2020 Share Posted May 10, 2020 I had the 4.6 with a GEMS and changed to a front mounted toothed wheel behind the crankshaft pulley. I timed it by using the gap on the timing ring on the flywheel. Ran as sweet as a nut! Cheers Peter Quote Link to comment Share on other sites More sharing options...
Eddie_V8 Posted May 10, 2020 Author Share Posted May 10, 2020 Cheers Bowie69, will give that a try. Peter, I've swapped from a 3.9 to the 4.0, the 3.9 had a flywheel like the 3.5 with no trigger ring pickup. The new engine didn't have a fly wheel with it. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.