Home page
SPONSOR AD

Topic: Dead, fuel but no fire!

in Forum: C3 Engines

Dead, fuel but no fire!

Posted: 9/1/08 7:07am Message 1 of 11
Limited Member
Send PM
Little Rock, AR - USA
Joined: 7/10/2007
Posts: 123
Vette(s): 1982 Collector Edition

  My '82 died on the freeway yesterday and after the tow it is safely in my driveway. That's the good news, the bad news is I'm stuck! I have fuel from my nozzles, and 12V to the coil. How can I check the ECM? The fuses are good. Any suggestions on troubleshooting the coil or rotor or distributor if it isn't the ECM?

Dead  terntes



SPONSOR AD:: (Our Sponsors help support C3VR)

Dead, fuel but no fire!

Posted: 9/1/08 7:39am Message 2 of 11
Profile Pic
Lifetime MemberLifetime Member
Moderator
Send PM
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
If the injectors are firing, that means the ignition module is sending a "crank" signal to the ECM. Ign. module failures are extremely common on HEIs, so even tho it appears to be functioning, it may not be functioning correctly.
Coils can also take a dump at any time, tho they normally give some warning, in the way of running rough/missing.

Have you removed the cap to look at the rotor? The tip of the rotor may have broken off...or the tip of the coil terminal in the top of the cap...that's fairly common, too.

Also...try dis-connecting the 4 wire connector from the distributor...NOT the power into the dist from the cap, but the other harness. This is the EST(Electronic Spark Timing) module harness. If that module goes kerput, it will cause a no spark. Unplugging it will confirm whether or not it is bad. If you unplug it, and the car then starts, the EST module is bad...
You can drive the car with the module un-plugged, but you'll need to put some black tape over the "Check Eng" light...Adams' Apple2008-09-01 07:51:43


Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Dead, fuel but no fire!

Posted: 9/1/08 7:59am Message 3 of 11
Limited Member
Send PM
Little Rock, AR - USA
Joined: 7/10/2007
Posts: 123
Vette(s): 1982 Collector Edition
Joel,
  We can always count on you! I've been through the distributor visually, nothing obvious. There was some continuity through both terminals of the coil, but not much, I'll check again and measure, the manual says it should be near zero, I could hear the beep, though.
  My car did run a little rough about five minutes prior to shut down, although it has been running great lately. While I had the distributor off I forgot to check for a broken timing chain, I'm going to do that now as I go through everything again, Especially the EST.
Thanks,
Terrence



Dead, fuel but no fire!

Posted: 9/1/08 8:08am Message 4 of 11
Limited Member
Send PM
Little Rock, AR - USA
Joined: 7/10/2007
Posts: 123
Vette(s): 1982 Collector Edition
Disconnecting the 4 wire harness stops the fuel nozzles from spraying, is this correct? More good news, my rotor turns when I crank the engine!
Terrence



Dead, fuel but no fire!

Posted: 9/1/08 9:27am Message 5 of 11
Profile Pic
Lifetime MemberLifetime Member
Moderator
Send PM
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Well CRAP! I fergot one IMPORTANT thing...when you dis-connect the EST connector, you have to jump terminals "J" and "G" together on the vehicle harness for it to start! You have to do this AT the EST module connector...
We used to jumper two wires right at the vehicle harness connector(not the distributor harness) by the distributor to make them run, but I forget which wires...I know one of them was purple, and I think the other was white. I'll have to get out a wiring diagram and check but you could try that real quick to see if your injectors come back to life...
Sorry...I ain't quite awake yet...Adams' Apple2008-09-01 09:29:16


Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Dead, fuel but no fire!

Posted: 9/1/08 9:42am Message 6 of 11
Limited Member
Send PM
Little Rock, AR - USA
Joined: 7/10/2007
Posts: 123
Vette(s): 1982 Collector Edition
I've ordered both coils from the auto parts store warehouse and they should be in by 1PM today; while I'm waiting I'll try the test on the harness. I'll let you know!
Thanks,
Terrence



Dead, fuel but no fire!

Posted: 9/1/08 10:23am Message 7 of 11
Limited Member
Send PM
Little Rock, AR - USA
Joined: 7/10/2007
Posts: 123
Vette(s): 1982 Collector Edition
My connectors are DCBA, with D-black (ground), C-brown, B-purple, and A-white. I've tried a bunch of combinations at module and harness and can get no fuel spray. When I re-connect the harness, the  nozzles spray good, either my jumpering is no good or my combinations are not right. I tried purple and white first.
terntes



Dead, fuel but no fire!

Posted: 9/1/08 10:40am Message 8 of 11
Profile Pic
Former Member
Send PM
Cramerton, NC - USA
Joined: 8/22/2006
Posts: 1094
Vette(s): black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion
OK guys, trying to learn something here.  I have found reference to the Electronic Spark Control Module in the service manual and found a diagram of it in the  assembly manual but cant determine what part of the car the diagram is showing and I've found pictures of it on ecklers site but still can't find it on my car.  Where in blazes is it located on an 82? Wacko


Dead, fuel but no fire!

Posted: 9/1/08 11:47am Message 9 of 11
Limited Member
Send PM
Little Rock, AR - USA
Joined: 7/10/2007
Posts: 123
Vette(s): 1982 Collector Edition
SUCCESS! Merely a bad module, located under the rotor inside the distributor. My coil was good. For less than $20 American, I am a happy camper. A 'volunteer' at the auto parts corroborated the jumper theory. He said jump the A&C connectors at the module, as that is usually the culprit on the module. They tested mine at the auto parts store and it failed in every catagory.
Thanks again for all the help!
Terrence.



Dead, fuel but no fire!

Posted: 9/1/08 12:02pm Message 10 of 11
Profile Pic
Former Member
Send PM
Cramerton, NC - USA
Joined: 8/22/2006
Posts: 1094
Vette(s): black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion
Yep, I know where the ignition module is located but where is THIS located?
 
Found the answer, behind the drivers seat near the ECM... Guess I should have dug a bit deeper before asking.  I didnt see the "illustration" link the first time.
Crossfire19822008-09-01 12:03:58


in Forum: C3 Engines


SPONSOR AD: (Our Sponsors help support C3VR)