if i set the timing at 6 advanced and have to vacuum advance on then at 1k rpm it starts to backfire, so i take the vac advance off and it's alittle better then i start to retard it and i can get 5500 if i retard it 25 degrees, what the hell is the problem. The motor was fuel injection and i put a edelbrook intake, holly 670 carb, and vac dizzy.

 

It sounds like the distributor is not indexed correctly with the cam. Was the no. 1 piston at TDC on the compression stroke when you removed/replaced the dizzy? And was your rotor oriented correctly? It only takes being one tooth off to cause the problem you describe.

 

what do you mean, i checked the timing with a timing light. put the light on pos and neg of battery and then number 1 plug wire. I have just headers on right now and can hear the timing in the exaust, sounds lopy when i retard it

 

What kind of vacuum dizzy? duraspark or other.
What's your idle set at?
How about a vacuum guage. Beg, borrow, or buy one. It will help a lot.
Here's my thoughts.
1. dizzy or ignition problem (180 degrees off)
2. vacuum leak.
3. balancer slipped the ring and it's not on the right timing mark it it's old. (long shot)

If you put in a bigger than stock cam let us know.

 

i have a msd ignition and coil, dont know what kind of dizzy. idle is set at 800 but if i bring the timing to 6 degrees adv the idle go to 1400. vacuum stays at 22psi, stock cam. I know the ignition, coil, and dizzy work cause we were trying to get my freinds motor running and borrowed those out of mine.

 

So you put it at 6 deg. and it idles at 1400 rpm. What happens when you turn the idle down to say 900-1000 rpm at 6 degrees? Stalls?

Don't be afraid to got up to 10 degrees with a stock cam. Different motors like different settings.
22psi, You can pretty much scratch the vacuum leak off the list.

 

well i keep the idle at 800 but when i retard the ignition so that it will turn 5500 without backfireing the idle will keep going down untill it stalls

 

Try setting your timing to 8 degrees with the idle up to 900-1000. Then see if your getting any detonation. Pull the plugs before and after and let us know what they look like.

 

well they look horrible right now
1. glossy, metal clean, porcelean white at top but black in grove
2. black everywhere, tips are grey
3. same as 2
4. dull, tan
5. same as 2
6. same as 4
7. same as 4
8. same as 2

 

can anyone help me figure out what these plugs are trying to tell me?

 

They should all be tan like number 4. I'd try pulling the distributor again and checking TDC and make sure the firing order is correct. I'd probably try the wires first.

 

What year engine? What type of camshaft? What firing order are you using?

I agree with the above in checking the distributor indexing. At the same time I would also check the marks on the balancer. To check that use a long skinny small screwdriver down the #1 spark lug hole. Use either a starter button or turn it by hand until the screwdriver comes to the highest peak (this is only approximate). Now look at the balancer...is it close to TDC or is it way off. If you do it right you should be within 2 degrees of TDC either way...thus you mark a slipped balancer off the list.

If you are using a 5.0 HO engine...the firing order is 1,3,7,2,6,5,4,8 instead of the old faithful 1,5,4,2,6,3,7,8. It makes a huge difference!

Kenny

 

It came out of an 87 grand marquis, it has the rollor lifters but it's not the HO, tried both firing orders and the HO firing order wont even start. what do you mean about the distributor indexing?

 

first thing to check is the balancer, pull the number 1 plug and roll the engine over by hand until you can see the piston coming up you should be able to see it when it's pretty much at TDC if not then stick a bolt in there turn until it stops (turn by hand only and lightly) mark the balancer then turn the engine the other way until stop and mark the balancer again, exactly between those marks is TDC and it better align with TDC on the balancer. If it doesn't your dampner could be bad as it might have slipped the outer ring. and this will throw your timing marks clear off.
Basically until you check that the timing marks on the dampner are correct the timing light is useless in this situation and that really does sound to me like it's your problem. only other issue is are you sure you on the #1 plug? I have seen people try to time off #5 and wonder why it's wrong.

 

Will an efi cam work with a carb? I have been told that my carb'ed cam won't run with efi.