I'm trying to break in my new cam, and I've only been able to run it for about 3mins at a time. After fixing the fuel leak, we got it running fine, but then noticed #3 and #6 were glowing, so I shut it down again. What could be going on? Preload on the lifters to much, to little? Timing way off? (I did noticed that on first start up that it sounded like it was missing, turned the dist counter-clockwise alittle, and it smoothed out some, yet it's nowhere's near set correctly) Help!!!

 

Timing is way off and causing a lean condition.

 

only 2 primaries are glowing, so it means that those to cylinders are lean like mark above...

im sure timing being off probly hurts more but id suspect that fuel leak..there may be no fuel coming out but that doesnt mean that air isnt getting in

 

it is odd that you only have two doing it. quite possibly a difference in valve adjustment or a vacuum leak, but it is normal on 3rd gen f bodies to have this problem. when i'm breaking in a cam or even just doing an initial run in on roller lifter set up's i set up a fan in front of the radiator and one blowing on each header. having your headers glow when your revving for an extended period of time under a very light load is normal.

 

valves are out of adjustment maybe? Overly rich condition will cause it too but you would have smelled it.

 

I think its late timing, but that would'nt cause it to go lean it's just burning the mixture in the header instead of the combust. cham. and those two tubes are prob the first ones to get hot.JMO.

 

Check to see if the wires are crossed on those cylinders. 3 and 6 follow each other in the firing order.

 

id check that fuel leak u fixed...

air being sucked in through there will cause a lean condiditon..

i really think youll find the problem there,


is this tpi or carb?....tpi intake like lt1 intake have a rich lean issue

the fron cylinders will run rich and the rears will run leaner..i think that fuel line fix is making that worse

 

I don't think my fuel leak will be affecting this problem, the leak was in the fuel rail connection on a TPI system. I'll try again, playing with the timing more. Do you think shutting it off so many times will affect cam break in?

 

do this..start it the way it is..how long does it take for the 3 and 6 to glow?...
if the primaries glow, the combustion is happeing in the header meaning the timing is behind..or theres a misfire in that cylinder
if the timing is off then all the primaries will glow, not 2..maybe let it run a little longer to see if any others glow

i really dont think its timing related..only 2 are getting hot
either those 2 cylinders are very lean, or you have 2 wires crossed

 

Ok, back'd off the lifter preload alittle, and moved the timing some, got it running. Problem is, it has a misfire. I cant seem to isolate it. I've got the timing set at 8*, adjusted the lifters ( backoff until tap, tighten until stops, give 1/4 turn), and still has a miss. Turn on the A/C, and it really hates it. I've pulled off #1 wire while running, and no change, thought this was the problem, pull off #8, and it almost died, really made me think #1 was the problem. But then pulled #3, no change, #5 no change. OK, 3 cylinders can have the wire yanked, and no change in RPM's, what the hell!!!

 

so your runnin on 5 then...

what condiiton are the cap and rotor in?..

maybe u crossed the wires that u pulled?...the cylinder is basically dead so when u pulled the wire nothing changed

check the resistance on your injectors...you may have fried a couple..they should be 14-16 ohms

check them all, but mostly the 3,6,5..because there was no change in rpm when the wires were pulled..meaning the cylinder is dead..and check them becasue the primaries were glowing on those cylinders..possibly meaning that those 2 injectors were on there way out and now there crapped...cause no change in rpm when u pull the plugs..

 

I double checked the cap and rotor last night, today I guess I'll look at the plugs and wires. Funny, everything was just fine before the cam swap. Injectors are fine, I sonic cleaned them at work, and flo-tested them as well.

If you recall, I've had this miss since the very first startup, even when I had fuel leak problems and had to shut down. This makes me wander about a bad lifter. What do you think?

 

theres something more thats up the 1 bad lifter..you have 3 dead cylinders..

pull the plugs on the ones that dont fire..kill the fuel on the fuse block so the motor wont run..

crank it over and look to see if you have spark on that plug...do that to all 3...if theres spark, then theres no fuel...

check for spark..then well go from there

 

Please refer to my new tread "runs like a 4cyl"
https://www.thirdgen.org/techbb2/sho...hreadid=176121

I can pull all the wires off one side of the cap, and it runs on 4 cylinders. Or at least it was, now I just can't quite get it to kick over. I know I have fuel pressure, as my guage is hooked up while I'm trying all this. I just can tell for sure if each injector is working for certain or not.