minimaquinas Posted August 28, 2014 Share Posted August 28, 2014 my 1990 3.5 v8 isnt sounding very responsive as it should it as been stood for a while so needed a new fuel pump in the tank and new petrol i have also cleaned both the carbs out it starts and runs but isnt as responsive as it should be any ideas on my next mission to make it sound better thanks in advance Quote Link to comment Share on other sites More sharing options...
Disco-Ron Posted August 28, 2014 Share Posted August 28, 2014 Clean/new plugs..... Clean/new points...... Quote Link to comment Share on other sites More sharing options...
minimaquinas Posted August 28, 2014 Author Share Posted August 28, 2014 it hasnt got points but i have cleaned the contacts in the dizzy cap Quote Link to comment Share on other sites More sharing options...
MattMatt Posted August 29, 2014 Share Posted August 29, 2014 IT could be the Dizzy. I had problems for a while which sounded like fuel but ended up being bent advance retard springs. If you have the 35DM8 dizzy you can just see them through the base plate. Be very careful if you remove the rotor cap as pulling it up can bring the spindle with it and bend/dislodge the springs - which was my problem. Quote Link to comment Share on other sites More sharing options...
Tanuki Posted August 29, 2014 Share Posted August 29, 2014 if you're in the dizzy, make sure both the centrifugal and vacuum advance mechanisms are free. If you grab the rotor-arm you should be able to twist it one way against obvious spring-pressure and it should then return smoothly to its rest poosition when you stop twisting. If you detach the vacuum-pipe from the carb and suck on it you should see things moving in the distributor base-plate - again this should be free and return to its rest position with an obvious 'click' when you release the suction. If either of these are not working smoothly your ignition will be retarded significantly at any speed above idle - causing dull response, excess fuel consumption, and overheating (potentially to the point where the exhaust-manifolds will glow a dull red). Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted August 29, 2014 Share Posted August 29, 2014 If it's just not performing as it should and isn't making violent shudders or misfires, then my betting it fuel. That said, the usual of new: -arm -cap -leads -plugs Never does anything wrong to help illuminate the issue. Is it on SU's or Strombergs? If the latter then my betting is they need a strip down and rebuild and the diaphragm replacing. I've seen it loads of times with these where they run for **** and people simply won't replace the split worn out rubber diaphragm in the Stromberg carb. Quote Link to comment Share on other sites More sharing options...
JeffR Posted August 29, 2014 Share Posted August 29, 2014 Ignition amplifier on the side of the dizzy can cause all sorts of problems! Quote Link to comment Share on other sites More sharing options...
minimaquinas Posted August 29, 2014 Author Share Posted August 29, 2014 Many thanks guys I will have a play with it over the weekend and keep you updated Quote Link to comment Share on other sites More sharing options...
minimaquinas Posted September 1, 2014 Author Share Posted September 1, 2014 Update I had a look at the distributer and it has a clear plastic cover on the inside can't see how it comes out I sucked on the vac pipe and no movement at all how do I get to the weights inside the dizzy Quote Link to comment Share on other sites More sharing options...
deep Posted September 2, 2014 Share Posted September 2, 2014 All good advice but I'd be heading straight to those carb diaphragms first. They're cheap and easy to change, so nothing scary there. If the engine runs very smoothly but lacks power, it could well be your distributor not advancing. You should be able to grab the rotor and twist it a few degrees, with the springs pulling it back smoothly. If not, you'll have to delve further. The vacuum advance is separate to the weight system and is a petrol saving measure, the operation of which you can't really feel while you're driving. If it's sticking, it will save you money to find out why! I have had a distributor with that plastic cover but can't remember what held it in place, sorry. Someone else is bound to help... Quote Link to comment Share on other sites More sharing options...
minimaquinas Posted September 2, 2014 Author Share Posted September 2, 2014 hi another update cleaned the plugs of which half where only in half way and loose and 4 and 6 leads where crossed sounds a lot better but still lacking something next is the dizzy Quote Link to comment Share on other sites More sharing options...
JDexter Posted September 6, 2014 Share Posted September 6, 2014 I have removed the plastic cover on my distributor. It has small cross point screws retaining it. It does say "Do Not Remove" but perhaps that is to avoid people fiddling about. This advance mechanism advice will be applied to my V8 (on SUs) later. Thank you. Quote Link to comment Share on other sites More sharing options...
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