css1634 Posted February 19, 2015 Report Share Posted February 19, 2015 I have a 77 620 points distributor, i purchased a 78 electronic one. It is a cardone 31-620. am i suppose to have a external box to complete the swap? If so what is part name i need? 1 Quote Link to comment
dr.feltersnatch Posted February 19, 2015 Report Share Posted February 19, 2015 you can use the gm hei module. http://community.ratsun.net/topic/17444-electronic-ignitions-for-l-motors-4-cyl/ 1 Quote Link to comment
css1634 Posted February 19, 2015 Author Report Share Posted February 19, 2015 Thank you, thats all i needed 1 Quote Link to comment
css1634 Posted February 21, 2015 Author Report Share Posted February 21, 2015 Ok i wired it as showed in pic, i hooked module to each side of coil. Nothing happens, no fire. I have stock coil and ballast, what am i missing? 1 Quote Link to comment
datzenmike Posted February 21, 2015 Report Share Posted February 21, 2015 Ok i wired it as showed in pic, i hooked module to each side of coil. Nothing happens, no fire. I have stock coil and ballast, what am i missing? Is the HEI module securely grounded to something like a fender? Needs to be grounded! The HEI works on 12 volts. Your ballast will drop this to 6-8 volts when running. Should start ok but may not run. I would suggest getting a '78 or later EI coil and get rid of the ballast and points coil. 1 Quote Link to comment
css1634 Posted February 21, 2015 Author Report Share Posted February 21, 2015 So eliminate ballast? Which i would take black and and white wire off and place on plus side of coil? And i have a later model coil i can use 1 Quote Link to comment
css1634 Posted February 21, 2015 Author Report Share Posted February 21, 2015 Just finished with a hei module swap on 77 620, truck will start but only when gas pedal and switch are released at same time..thats best i can explain it. Idle fair, revs great, diesels like hell, the red wire solenoid i hear click i hear nothing out of white wire solenoid, truck even runs same with it totally out, that isnt normal is it? 1 Quote Link to comment
datzenmike Posted February 21, 2015 Report Share Posted February 21, 2015 Wire it like the diagram. You need a later '78 and up EI coil capable of the higher current the HEI module will draw through it. So... is the HEI properly grounded??? 1 Quote Link to comment
datzenmike Posted February 21, 2015 Report Share Posted February 21, 2015 Rather than start another post on this we could keep it in the HEI thread? Are you saying the engine turns over during start but only fires when you release the key? There are two wires from the ignition switch. One has power in the ON position, (but might be off during start) the other during START. Both wires should be connected to the + terminal of the coil to provide power during start and run. Diesels? do you have the stock carburetor on it? 1 Quote Link to comment
css1634 Posted February 21, 2015 Author Report Share Posted February 21, 2015 Yes it only fires when i release key and yes stock carb 1 Quote Link to comment
datzenmike Posted February 21, 2015 Report Share Posted February 21, 2015 Then the start wire is likely missing. Refer to this diagram... On the '77, the On signal is the Black/White stripe wire. The START is the Black/Blue stripe wire. To be sure test with a meter. Just join together. Dieseling... Fuel to the idle circuit is turned off by a solenoid on the carb when the ignition is turned off. You should hear a click sound near the carb when the ignition is turned on, off, on, off. The idle cut solenoid is on the rear right side of the carb and has a Red wire to it. It may also have a black sheath covering it also but the wire inside is Red. This should have 12 volts only with the key on. Assuming the idle cut is working and hasn't been tampered with, other causes of dieseling are... Idle set much too high. Choke stuck on or part on when engine is warmed up. Carb flooding Compression too high for the octane rating of the fuel you are using. Spark plug too high a heat range or wrong make. Should be NGK BP6ES-11 with 0.039"-0.043" 1 Quote Link to comment
css1634 Posted February 25, 2015 Author Report Share Posted February 25, 2015 Ok i found the wires, everything wired up, starts good has a slight miss tho dieseling is hardly there. I am going to check plug make and gap and set timing with light before i turn and scscrews on carb. Thanks for help 1 Quote Link to comment
datzenmike Posted February 25, 2015 Report Share Posted February 25, 2015 .... and yes stock carb Dieseling... Fuel to the idle circuit is turned off by a solenoid on the carb when the ignition is turned off. You should hear a click sound near the carb when the ignition is turned on, off, on, off. The idle cut solenoid is on the rear right side of the carb and has a Red wire to it. It may also have a black sheath covering it also but the wire inside is Red. This should have 12 volts only with the key on. Assuming the idle cut is working and hasn't been tampered with, other causes of dieseling are... Idle set much too high. Choke stuck on or part on when engine is warmed up. Carb flooding Compression too high for the octane rating of the fuel you are using. Spark plug too high a heat range or wrong make. Should be NGK BP6ES-11 with 0.039"-0.043" Dieseling is an easy fix. 1 Quote Link to comment
banzai510(hainz) Posted February 25, 2015 Report Share Posted February 25, 2015 Dieseling is an easy fix. push the pedal down when shutting off with key. 1 Quote Link to comment
css1634 Posted February 28, 2015 Author Report Share Posted February 28, 2015 Ok timing is set, plug gap is right, however its a champion cross reference plug. Choke pull off is working, wont idle until warm, then has a slight stumble. The sound from exhaust is like a low growl or popping every few secs. runs down road ok yet can still hear the skip a little. At full throttle while driving it will stall til i ease off a little. 1 Quote Link to comment
css1634 Posted February 28, 2015 Author Report Share Posted February 28, 2015 I will add the mixture all the way in or out has little to no effect 1 Quote Link to comment
dr.feltersnatch Posted February 28, 2015 Report Share Posted February 28, 2015 check for vacuum leaks 1 Quote Link to comment
banzai510(hainz) Posted February 28, 2015 Report Share Posted February 28, 2015 if its timed and dist(electric) with the correct coil ect..) is solid make sure the valve lash is ok. Otherwise than that its a carb issue esp if a stock carb9most are worn out by now). vacuum . or crack carb adapter if a weber dgv. stock carb make sure the 2nd flap works or is not stuck 1 Quote Link to comment
css1634 Posted March 3, 2015 Author Report Share Posted March 3, 2015 Ok i am running thru list of things that have been suggested, is it possible for jets to be mixed up in carb? Maybe to much at idle and not enough at full throttle going down highway? Quote Link to comment
banzai510(hainz) Posted March 4, 2015 Report Share Posted March 4, 2015 jets mixed up? hardly believe that one. Quote Link to comment
css1634 Posted March 5, 2015 Author Report Share Posted March 5, 2015 Ok i did take carb off, facing engine looking towards bed, jet on right is a 160 and clogged jet on left is 99 and clean, jet on right was dry, while left was wet. Does this all sound normal? Quote Link to comment
css1634 Posted March 5, 2015 Author Report Share Posted March 5, 2015 The jets im referring to are the ones below the float bowl behind 12mm nuts Quote Link to comment
datzenmike Posted March 5, 2015 Report Share Posted March 5, 2015 Yes correct! they are usually about 100 and 160 give or take. A clogged primary will run poorly if at all. A clogged jet has no effect on the idle as it has it's own gas supply and its designed into the carb. Quote Link to comment
css1634 Posted March 5, 2015 Author Report Share Posted March 5, 2015 Ok i cleaned them up, secondary side is barrel open by vacuum correct? And does this carb have a idle jet? Quote Link to comment
banzai510(hainz) Posted March 5, 2015 Report Share Posted March 5, 2015 far as i know all carbs have a idle jet. just soemtimes the mixture needs adjustmant first as that can act like a idle jet. The brass screw at base of carb with the tension spring on it. also ck to make sure the second barrel flap is closed otherwise youll never idle Quote Link to comment
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