Big Problems - help please - can't get it running right

Paul Perreca

New Member
Mar 30, 2005
1,085
0
0
it runs, it does not idle AT ALL - when you let the R's go down and than you get them back up it backfires n puts and backfires - the spark plugs are black and they are bran new, the thing is running rich as all hell - what in the HELLLLLLLLLLLLLLLLLLL am i supposed to adjust?? i figured i'd look at the surging idle checklist, but honestly, i have no idea what the **** any of that **** is and i don't know how to adjust it- i am at a complete, full days wasted loss
 
the firing orders has been double n triple checked lol - Mr. Yount... Shortblock - E-303 camshaft, Edelbrock RPM heads - cobra intake, 70 mm throttle -

MASS AIR CONVERSION - 76mm C&L MAF -

we just put the engine in, and have been hooking things up for about 3 weeks - finally started it today, and it started, runs good when you keep the throttle into 2000 RPMS - when u let off - it dies - when you move the R's around, the exhaust AND intake (right by the massair meter) pop and backfire n do goofy **** - Must have some answers, will not sleep until it runs good lol help guys, appreciate everything !!!

and NO it was never running right, this is a bran new 302 shortblock that we built, and this is it's first firing up - and the spintechs sound goddamn mean by the way, at 2000 R's, the spintechs humm "beeeeeeeaaaaaasssssttttt" lol

But anyway - aside from the gay mufflers, i gotta get this thing in check, before i have to have a professional look at it - thanks again guys!!
 
Paul, sounds like you have a vacuum leak. What gave it away was the lean pops you hear through the MAF. Vacuum leaks in an EFI car = a lean condition since you are letting in unmetered air.

When I first got my 347 running I had the exact same issue. Lean pops and it wouldn't idle. I ended up not capping off one of the many vaccum ports on the upper manifold and i had a leak at the lower manifold too.
 
sounds like you got a lower intake leak. plugs are pry black from oil lrrking into intake ports on head. pull your dipstick and see if your oil smells like gas. if it does you know thats the problem.
 
Check the timing or at least mess with the timing so you can get it run. After that check hard and close for vac leaks. Popping thru the intake sounds like it is a timing issue. Start there and see what happens.
 
spittinstang said:
sounds like you got a lower intake leak. plugs are pry black from oil lrrking into intake ports on head. pull your dipstick and see if your oil smells like gas. if it does you know thats the problem.

does this mean i am totally screwed and have aloootttt more work to do? damnit dude - if my oil smells like gas i'm comin after you, and thankin u lol i will check asap -

and Grn92LX - when u say lean, what do u mean by that, because thought i was getting TOO much gas - where the hell do i look for a vac leak? i have all my smog stuff plugged off, and the heads don't have any smog stuff, and the intake is all hooked up - could i have vaccuum lines mixed up? in wrong spots? help - lol
 
Paul Perreca said:
and Grn92LX - when u say lean, what do u mean by that, because thought i was getting TOO much gas - where the hell do i look for a vac leak? i have all my smog stuff plugged off, and the heads don't have any smog stuff, and the intake is all hooked up - could i have vaccuum lines mixed up? in wrong spots? help - lol

Start spraying carb cleaner around where the lower intake meets the head or any other suspected area. When I say lean, meaning not enough fuel.

Are you sure you followed the cobra intake vacuum line routing properly? There is a nice helpful pic floating around the net.

You could also have the rockers adjusted wrong.
 
Did you degree the camshaft upon install? Did you do the maf conversion as a part of the changes? As mentioned above, when you do that the MAP (manifold absolute pressure) sensor becomes a BAP (barometric absolute pressure) sensor and the vacuum port should be left open to the atmosphere, not plugged into the manifold like it is with the speed density system.
 
good tips - will definately be checking up on this stuff - i hope the rockers are correct, and we did not degree the cam, it just went right in lol - neway - seriously appreciated - i'll get back to you on progress on wednsday, because we are too busy to worko n it again till then lol
THANKS!
 
Paul..first check your TPS setting. Next pull the codes with the engine off. Next check all your vac lines to ensure they are connected..all of them including canister and PCV. If you didn't degree the cam did you install it dot to dot? Are you sure you did all the required wire swaps for the Mass air conversion..double triple check your wires. Did you get the grounds in place and secure on steel surface, not painted?Is the orange ground wire by the passenger firewall connected? All I can think of for you to check..but keep at it.