Cranks but no start
Thread Starter
Pro
Joined: May 1999
Posts: 538
Likes: 1
From: Tijeras NM
Cranks but no start
this is a straight carburated engine, offroad only. it's in a C4 tho. anyway, it was running fine, now it cranks fine but wont start. there fuel going into the carb, and there's spark at the plugs, but it will not fire - not even try to. any ideas? i've cleaned the plugs, gapped them at 40 but still nothing. it used to run at a gap of 45.
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: Cranks but no start (ZR1Rob)
this is a straight carburated engine, offroad only. it's in a C4 tho. anyway, it was running fine, now it cranks fine but wont start. there fuel going into the carb, and there's spark at the plugs, but it will not fire - not even try to. any ideas? i've cleaned the plugs, gapped them at 40 but still nothing. it used to run at a gap of 45.
[Modified by Glock'94, 1:22 AM 12/30/2001]
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: Cranks but no start (ZR1Rob)
you can visually see the fuel going down past the throttle blades? Smell fuel? Stick finger down air horn and pull it out wet with fuel? Color and distance jumped of spark? What kind of dist? We are hungry for more info :D
Thread Starter
Pro
Joined: May 1999
Posts: 538
Likes: 1
From: Tijeras NM
Re: Cranks but no start (89 Paul in cal)
first, this is not a zr1, it is an '84 that now has a stroked small block with about 550 hp for offroad use only.
anyway, it has a mallory IV ignition and a magnetic breakerless distributor. there is spark as ive pulled plugs and checked for spark jump to the block as i crank it. the holley 700 double pumper will feed fuel when the lever is pulled. so that is not the problem.
i have been wondering if there is too much oil in the pan because it doesnt have a dipstick. i had pulled a plug out to put an oil gauge in, but forgot to put the plug back in after testing, and jed clampett would have been impressed with the gusher i created. so i put in another quart and that may have been too much.
the plugs are wet, but maybe they have oil on them as well as fuel. i'm going to go outside now and drain a half quart and try again. maybe oil splash is screwing up the ignition mixture. i'll let you know.
anyway, it has a mallory IV ignition and a magnetic breakerless distributor. there is spark as ive pulled plugs and checked for spark jump to the block as i crank it. the holley 700 double pumper will feed fuel when the lever is pulled. so that is not the problem.
i have been wondering if there is too much oil in the pan because it doesnt have a dipstick. i had pulled a plug out to put an oil gauge in, but forgot to put the plug back in after testing, and jed clampett would have been impressed with the gusher i created. so i put in another quart and that may have been too much.
the plugs are wet, but maybe they have oil on them as well as fuel. i'm going to go outside now and drain a half quart and try again. maybe oil splash is screwing up the ignition mixture. i'll let you know.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: Cranks but no start (ZR1Rob)
If you have spark, then use your timing light to determine that it is occurring at the right time. Pull all the plugs and wash the gas/oil off and dry them, then replace. Wet plugs won't fire.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Cranks but no start (ZR1Rob)
Checked compression? If it was running I doubt it's your problem, but a friend and I beat our brains out for a long time over no compression. Turns out his valves were too tight.
Again, I doubt it's the problem, but it wouldn't hurt to check.
Again, I doubt it's the problem, but it wouldn't hurt to check.
