I'm spent... need some ignition advise.

[mopar_1974]

Put a new engine in my truck ('84 ram) and now i'm down to tuning it. I can't seem to get a timing light to work on it. I tried 3 different timing lights but the flashes are very erratic on cyl 1. cyl 3 seems to be a little better (just tried for comparison) swapped cap, rotor and new plug wire. Doesn't seem to help. The truck will idle and rev but dies under load, all cylinders fire but i'm sure the timing is off (unless i got really lucky). Just rebuilt the eddy carb. the timing light seems to be better at higher rpm. The coil is new but cheap parts store brand. I'm going to start with a new msd coil. I'm also looking to upgrade the ignition as it's a pretty built 360 with stock/stock replacement ignition. Any recommendations without breaking the bank? I'm just starting to get frustrated with it and looking for any guidance. Thanks guys.

 

[john27pa]

sounds like a vacuum leak?? Maybe around carb base gasket? Check on back of carb for the big hole and make sure its sealed good. Also look down carb when at idle and see if your not dripping fuel down primaries while its running. Mine did that. Had to take back apart and use air pressure to "hit" every nozzle, tube. whatever. Blew something out because it works great now. Didn't need a rebuild gasket kit either- just becareful with your gaskets when tearing down again.

 

[KitCarlson]

What is the voltage engine ground to + side of ignition coil? Also measure ignition box case to battery - voltage. And battery - to chassis voltage. Please report back what you measure.

 

[Oldmanmopar]

I had the same problem with a 87 dodge ram. I took the electronic ignition harness from a kit I had and wired it in and eliminated the factory hook up. It corrected the problem. It even started better hot. It was a blower motor and it drove me nuts for awhile until I did this. Later when the funds permitted I installed a MSD 6-AL. There was something in that truck that interfered with the orange 4 wire control box. Steve

 

[dennday67]

I had to do the same for my neighbors truck. Went back to a basic electronic ignition system from a 70s dart. If it has the "computer" behind the driver side headlight with a billion wires coming out it has what I was told a carburetor feedback system and wont work with an after market Carb. Wasn't terrible but enough to make me want to pull my hair out.

 

[BillGrissom]

You didn't tell us the voltage at coil+ yet. If you don't have a multimeter, get one (free w/ HF coupon) or take to a shop and pay $$$. I looked at a guy's car recently when it was idling poorly and it also wouldn't flash reliably with my clamp-on timing light. I measured only 6 V at coil+ (should be ~9 V w/ a ballast), so guessed a weak spark. When it does it, try running a jumper wire to put a full 12 V on coil+, but only for 1 min. The reason it dies under throttle is that it is harder for the spark to jump the gap at higher cylinder pressure.

I suspect that 84 didn't have a ballast resistor, so should have a full 12 V at coil+. They did all that in the "spark computer", so hard to change. If you want to control spark yourself, buy a $45 "ready-to-run" distributor on ebay (Steve White Performance and others). It has built-in HEI module and uses the traditional centrifugal weights and vacuum advance.

 

[mopar_1974]

Thanks for the replys guys, i checked for vacuum leaks, ive got one at the brake booster so i'll have to get a new seal for that. i torqued and retorqued the base gasket down so i think i'm fine there but i will probably put a new thicker gasket on just in case. I already ran into a problem with that. I'll check voltage on the coil tonight. It does have a ballast resistor. might swap that out but i'll probably wait until i get the supplied resistor with the blaster 2 coil. I aprpeciate all your suggestions