Thread: Strange problem with 454 running rich

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I recently got myself a 69 El Camino with a 454 in it (not original), and noticed that it was running pretty rich. I took the temp of each header tube real quick looking for one that was not hot to see if I had a misfire, but instead I found that 3 of the 4 pipes on the drivers side were off the scale of my IR thermometer (about 1200 degrees or so) at idle with the engine warmed up. The other pipe on the drivers side and all 4 on the passenger side pipes were around 400 degrees, and the passenger side exhaust definitely smells more rich than the driver side. I took out all the plugs and the 3 'hot' ones were definitely running lean since they were light brown, and the rest were black and wet. I'm already going to get new plug wires for the car since they all look pretty worn and one of them has a burned up end on it, but why else would only 3 of the cylinders be running lean? Maybe the camshaft has some rounded lobes on it and the valves aren't letting in enough fuel?

Hmm, after tearing into the enging a little more I found that the distributor is waaaay out of time. So much that whoever worked on it last had to move all of the plug wires clockwise one post to get it to fire and the whole distributor body is clocked way over clockwise too so the vacuum advance is pretty close to the firewall. Sounds like I'll need to pull the distributor and drop it back in the right place and get the motor timed before I try to track down why I'm getting the rich/lean issue, no?

I finally have an update on my problem. I dropped the distributor back in after lining up the marks on the balancer and promptly found out that the balancer mark does not line up with TDC at all. Great. I was able to get the motor to fire after getting it as close to TDC as I could figure using a piece of wire stuck into the #1 spark plug hole to feel the piston. I let it warm up and tested the exhaust temps. They are all about 400 degrees now, but there is a pretty good misfire at idle and under power. I replaced the cap, rotor, carbon brush (it's an HEI), plugs, and wires when I retimed the engine so I was pretty sure that the misfire was not coming from the ignition. I adjusted the rocker arms with the engine still warm and now it will barely run. I've adjusted valves plenty of times before on small block motors and never had any problems, but this big block does not like what I am doing. I used the EO-IC method of adjustment where you adjust the intake when the exhaust is just opening and adjust the exhaust when the intake is closing. I've heard that this method may not work for extremely radical camshafts, and now I'm thinking that this cam is more radical than I thought. I was going to try to re-adjust the valves using the TDC method but since the timing marks are off that will probably not work as well. It's looking like I might have to take the timing cover off so I can make sure that the timing chain is set correctly, what model camshaft is in there, and mark TDC. But I really don't want to take the engine down that far... Any ideas?

get a TDC tool that screws in the spark plug hole, set it on #1 @ TDC, then either mark your dampner, or get the correct size timing tape for your dampner and put it on.

Oh awesome, I didn't know they made a tool for finding TDC! I'll get one ASAP so I can get my balancer marked and start fresh. Thanks Dave!

Not sure what size plugs your engine has, but here's a link to Summit and a TDC finder for plug holes...just pick the size to match your plug size...They have the timing tapes and pointers, too.

http://www.summitracing.com/parts/SUM-900189/

http://www.crankshaftcoalition.com/w...op_dead_center

Before you pull the timing cover...check the vibration damper!

That old rubber deteriorates over time.

I had one where the outer ring slipped on the vulcanized rubber.

try replacing the vibration damper, recheck TDC and your distributor location and then timing

I just wanted to thank everyone for their help. I got myself a TDC tool and found that the balancer had slipped or the timing mark on the front cover was wrong, but either way the mark was off by about 2 inches. I got the valves adjusted using the TDC method and re-timed the distributor and now if runs like a champ! Still a little rich, but I think the carb is jetted way too big. One day I'll get the carb jetted down and get the racey camshaft out of there along with some new pushrods (they look like they were a mix-n-match of leftover parts) but that's going to have to wait until I steal this engine out of my wifes El Camino and put it in my Chevelle!

One last thing. Tap into the fuel inlet line at the carb and install a tee. Run a 1/8" nylon pressure line up to the cowl just in front of the windshield. Temporarily affix a mechanical fuel pressure gauge to the cowl with duct tape, tie wraps or whatever (it's temporary) and monitor fuel pressure as you drive. No modern 4-bbl carb needs more than 5 psi at the carb inlet. More pressure than that will overpower the needle and seat and blow raw fuel into the intake manifold. If you observe in excess of 5 psi, install a regulator.

Oh ok, thanks again for even more info! I'll try the pressure gauge to see what this pump is putting out. I think I've got an old pressure regulator laying around somewhere, but no idea if it is still any good. I noticed that the fuel pump is the incorrect type for the car since it is a 3 line type with one of them plugged up with a bolt stuck in the end of it (real safe, no). I should probably just cut my losses and get a new correct pump and fuel pressure regulator just for good measure.