92 Z28 5.7 need help no fire
#1
09-30-2015, 01:56 AM
92 Z28 5.7 need help no fire
I recently acquired this Z28 and I've always wanted one but no spark . I've got new plugs , plug wires, distributor cap and button, also replaced module in distributor no spark . Any help would be a blessing thanks
#2
09-30-2015, 10:57 AM
Welcome, Marc and congrats on the purchase.
First, verify with test light/meter and an assistant, the distributor is getting ignition power in both IGN & START positions.
No power, then jumper from battery positive post to HEI and she if she starts.
If she does, then losing ign power from ign switch to coil.
If you have power, remove dist cap and see if rotor button revolves.
No motion, timing chain broken and timing set behind water pump needs replacing.
Beware: if this event has happened, figure on a bent valve as SBC's are interference engines - valves do meet pistons.
While cap is off, measure pick-up coil resistance should be between 1000-1500 ohms with it disconnected from module.
All the above is good, pull a plug wire and hold 1/4 inch from ground and crank - should have a spark - blue is best.
Buy a Haynes manual - at least it's better than nothing.
First, verify with test light/meter and an assistant, the distributor is getting ignition power in both IGN & START positions.
No power, then jumper from battery positive post to HEI and she if she starts.
If she does, then losing ign power from ign switch to coil.
If you have power, remove dist cap and see if rotor button revolves.
No motion, timing chain broken and timing set behind water pump needs replacing.
Beware: if this event has happened, figure on a bent valve as SBC's are interference engines - valves do meet pistons.
While cap is off, measure pick-up coil resistance should be between 1000-1500 ohms with it disconnected from module.
All the above is good, pull a plug wire and hold 1/4 inch from ground and crank - should have a spark - blue is best.
Buy a Haynes manual - at least it's better than nothing.
#3
10-01-2015, 09:09 PM
92 z28
Hey thanks a lot for your help I'm gonna try that in a few minutes . One question though what the HEI?
#4
10-02-2015, 10:07 AM
Join Date: Oct 2007
Location: The 'Burbs of Chicago
Posts: 18,306
It's a type of "all in one" GM distributor that has the coil on top of the distributor cap. Easily evidenced by having no center external coil wire on top of the cap.
But, that's not what you have, unless someone has replaced the original distributor. Your coil, what you want to check for incoming power, is mounted externally, on the passenger side of the distributor.
But, that's not what you have, unless someone has replaced the original distributor. Your coil, what you want to check for incoming power, is mounted externally, on the passenger side of the distributor.
#5
10-09-2015, 02:49 PM
Idk
It's a type of "all in one" GM distributor that has the coil on top of the distributor cap. Easily evidenced by having no center external coil wire on top of the cap.
But, that's not what you have, unless someone has replaced the original distributor. Your coil, what you want to check for incoming power, is mounted externally, on the passenger side of the distributor.
But, that's not what you have, unless someone has replaced the original distributor. Your coil, what you want to check for incoming power, is mounted externally, on the passenger side of the distributor.
#6
10-10-2015, 09:21 PM
Welcome, Marc and congrats on the purchase.
First, verify with test light/meter and an assistant, the distributor is getting ignition power in both IGN & START positions.
No power, then jumper from battery positive post to HEI and she if she starts.
If she does, then losing ign power from ign switch to coil.
If you have power, remove dist cap and see if rotor button revolves.
No motion, timing chain broken and timing set behind water pump needs replacing.
Beware: if this event has happened, figure on a bent valve as SBC's are interference engines - valves do meet pistons.
While cap is off, measure pick-up coil resistance should be between 1000-1500 ohms with it disconnected from module.
All the above is good, pull a plug wire and hold 1/4 inch from ground and crank - should have a spark - blue is best.
Buy a Haynes manual - at least it's better than nothing.
First, verify with test light/meter and an assistant, the distributor is getting ignition power in both IGN & START positions.
No power, then jumper from battery positive post to HEI and she if she starts.
If she does, then losing ign power from ign switch to coil.
If you have power, remove dist cap and see if rotor button revolves.
No motion, timing chain broken and timing set behind water pump needs replacing.
Beware: if this event has happened, figure on a bent valve as SBC's are interference engines - valves do meet pistons.
While cap is off, measure pick-up coil resistance should be between 1000-1500 ohms with it disconnected from module.
All the above is good, pull a plug wire and hold 1/4 inch from ground and crank - should have a spark - blue is best.
Buy a Haynes manual - at least it's better than nothing.
Last edited by Marc Pierce; 10-10-2015 at 09:24 PM.
#7
10-11-2015, 09:09 AM
This system should not be complicated to figure out. Are you sure it is rotating? If it was in my bay first step would be disconnect the MSD box and get the system back to stock. It is not that I hate MSD it just all the trouble trees and tech guides don't know you have a MSD box.
Part 1 -How to Test the GM Distributor Mounted Ignition Module
Part 1 -How to Test the GM Distributor Mounted Ignition Module
Last edited by Gorn; 10-11-2015 at 09:13 AM.
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