Posted by Hamish on September 11, 2007, 7:29 pm
203.97.106.223

Here's the story of an HEI dizzy conversion that did not work - or has not yet, just so anyone thinking about this will know of the down side. Some of you may even remember me posting on this a while ago... Encouraged by a pos on another forum, and other Rangie owners I've met, I bought a second hand Chev HEI & had the base mount modified to fit into the engine. The Chev base is taller that the Buick, so it sits clear of most obstacles & hardly needed any grinding. So far so good. Wired it up, started it and wow - it ran. Set the timing & all seemed well, so I set off on a test drive. Bad plan. It's 10pm on a wet night. Got 3km away from home and it died. Would not re-start. Dead as a dodo. Walked home, got the Lucas dizzy off the garage floor, walked back & fitted Prince of Darkness dizzy in the dark & rain. Set timing by guess, hit starter & phew... we are away. Took HEI to the guy who tunes my Rangie for LPG & he said he knew nothing about them, but the auto electricians nearby did. Took HEI there where it was tested & pronounced to be just fine. They suggested the low voltage feed might not be delivering enough volts, so I rewired out to the dizzy just in case. Put it back into Rangie, hit starter & it went. Warmed it up, stopped it to connect timing light & it won't start. At least it was not out on the road this time. Abandoned it until another night. Tried again - still dead. Re-fitted Lucas.. Left HEI on the shelf for months, until I found someone else who said he knew about HEI dizzys. Described the symptoms to him & he suggested a dodgy module was the culprit. So the module got replaced, and he found the last module had been fitted without heat-sink paste. Maybe that was it... Re-fitted HEI & hit starter. It fired up sort of - like on two or three cylinders... Stopped it. Tried again... same. Back to expert 2, who decided to come around & look. Fire it up & it runs on 3. Expert 2 hauls out a plug & finds it sooty & wet with unburned fuel. Says we need clean plugs. They were a fresh set for this round of HEI fitting. Removed plugs for cleaning, and the HEI as I needed a working 4WD for the weekend. Re-fitted Lucas & old plugs... fired up first kick. Damn Rangie ran just fine all weekend. So, for the next attempt, it's drive the beast down to the garage using the Lucas & fit the HEI, and leave it to them. After a lot of experimenting, they found it can be started, provided the spark is well advanced. At that setting it won't pull the skin off anything, but once started , the timing can be reset to TDC and it runs quite well. Turn it off and it won't restart properly - runs on about 3 cylinders if very lucky. Now the garage suggests the HEI is sent to another town to somebody who can check the profile of the module to see why it behaves so strangely.... Which was a bit of a waste of time, as it has only confirmed that this HEI dizzy for no apparent reason shifts the timing forward when running. Which means the timing can be set to allow it to start or run OK, but not both. We still don't know why... But the module is the main suspect. The latest expert says he has run into similar problems with a brand new HEI from a local Chev parts supplier. So - even if I had bought a new one I still could have ended up with this mess. And, once again it's back to Joe Lucas who is proving surprisingly reliable right now...