grannyknot Posted April 20, 2013 Share #1 Posted April 20, 2013 (edited) Trying to start L28 engine that I've just put into a 70/240z -rotor and cap are new -spark plugs and wires used but in good condition -newish Pertronix 3.0 ohm coil -GM HEI ignition module red and green wire from magnetic p/u from distributor, red going to W and green going to G on the HEI yellow wire coming from B (HEI) going to positive on coil and red wire coimg from C (HEI) going to negative on coil Existing black wire going to negitive on coil, existing black/white wire going to positive on coil. Existing blk/white and grn/white resistor wires jumpered together Spark plug wires are correctly numbered 153624 in a counter clockwise direction from the mark on the cap. Thanks, Chris Edited April 20, 2013 by grannyknot Link to comment https://www.classiczcars.com/topic/46323-did-i-wire-this-wrong-no-spark/ Share on other sites More sharing options...
grannyknot Posted April 20, 2013 Author Share #2 Posted April 20, 2013 Okay, solved one problem, I removed the grounded black wire from the neg side of the coil and it starts right up but only runs for 1-2 seconds then shuts down.Re-starts easily but shuts down again in 1-2 seconds, it's got to be electrical, the fuel pumps works just fine.Chris Link to comment https://www.classiczcars.com/topic/46323-did-i-wire-this-wrong-no-spark/#findComment-421058 Share on other sites More sharing options...
Zed Head Posted April 20, 2013 Share #3 Posted April 20, 2013 Are you using carbs or EFI? The problem sounds typical of the fuel pump contact in the AFM switch not completing the circuit, due to low air flow or being out of adjustment. Or, if it's a 78 or later system, the oil pump switch or alternator are not feeding the right fuel pump control relays. Link to comment https://www.classiczcars.com/topic/46323-did-i-wire-this-wrong-no-spark/#findComment-421059 Share on other sites More sharing options...
grannyknot Posted April 20, 2013 Author Share #4 Posted April 20, 2013 More info, if I mash the gas pedal and keep the revs at 4000 I can keep the engine running but as soon as the revs come down under 4000 rpm the engine dies and there is a kind of back fire through the carbs and a bit of smoke coming out of the air filters but no flame. I didn't touch the timing from when it was running last but I did block off the vacuum advance on the distributor. Link to comment https://www.classiczcars.com/topic/46323-did-i-wire-this-wrong-no-spark/#findComment-421060 Share on other sites More sharing options...
grannyknot Posted April 20, 2013 Author Share #5 Posted April 20, 2013 (edited) Zed, I'm using carbs, triples SK/OERs. I haven't adjusted them since the engine ran last fall. I have purposefully disconnected the Oil pressure switch so that couldn't mix things up. I have the fuel pump running off of the blk/white ignition wire and it is running.It runs at 4000rpm but dies if I go under that with back firing through the carbs, that sounds like a timing problem to me but I can't see how that would be, I haven't even losened the distributor base. Edited April 20, 2013 by grannyknot Link to comment https://www.classiczcars.com/topic/46323-did-i-wire-this-wrong-no-spark/#findComment-421061 Share on other sites More sharing options...
Zed Head Posted April 20, 2013 Share #6 Posted April 20, 2013 Figgers. Since you've confirmed spark (it stays running at 4000 RPM), you might draw more attention with a new title containing the word carburetor. The carb guys and the wiring guys tend to be two different groups. Good luck. Link to comment https://www.classiczcars.com/topic/46323-did-i-wire-this-wrong-no-spark/#findComment-421062 Share on other sites More sharing options...
grannyknot Posted April 20, 2013 Author Share #7 Posted April 20, 2013 Please disregard this thread as I have solved the original problem, I'll start a new thread concerning the current problem.Thanks,Chris Link to comment https://www.classiczcars.com/topic/46323-did-i-wire-this-wrong-no-spark/#findComment-421063 Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now