Help!! Engine Miss

[Nitroman]

Strange that it ran fine on the dyno, only to put it in the car and something fail.... I had one that popped and cracked really bad but only under a load and further upstairs(3,000 and up). You mentioned that you literally replaced every ignition component in the system, even said you tried another distributor... Did you by chance try just a straight up HEI of some sort to hooked straight to the battery to eliminate anything else in the car ?? It's possible to come up with multiple bad boxes. What box was used on the dyno ?? One from your car ? Or one that was already there ? I don't think changing the switches did anything to you, the addition of ground wires I suspoect is because the new ones are lighted... I was gonna suggest magnetic pick-up until you said you tried the whole dist. Hmmm... this could prove to be interesting, especially since from the looks of things, you've been fighting it for better than 2 MONTHS !!! As they say "I'd rather be racing !!!"

Maybe go back and make SURE your big red & black to the battery are intact from end to end.

Just trying to help.

[Ben Kallies]

Dion,

I sent the carb back to Deano and made him aware of the issue. He completely disassembled the carb, and checked all of the passages. Everything looked good.

Dirk,

Thanks for the offer to help. I've got family in LaCrosse - beautiful area. Ground wires are my current focus. I'll be changing some things around even if it doesn't prove to be my problem.

Nitroman,

I plan to eliminate the vehicle wiring from the equation one way or another in the testing process. I think I'll start with what Alan suggested and run all MSD wiring straight to the battery to eliminate the rest of the vehicle wiring from the equation. If that doesn't do it, the next step is an HEI to eliminate the ignition as well. The second MSD box that I tried was brand new, and will be in retested in another vehicle this weekend or next, so that will confirm whether or not that box is good.

-Ben

[Ben Kallies]

Well, it's winter in WI, and I had to put my car to bed without having found a solution to the mysterious engine miss. I did however, make some progress in November.

I installed a brand new HEI distributor with a single wire going direct to the battery. In theory, this should eliminate the entire ignition system from the equation. Needless to say, the problem persisted.

With the HEI still in place, I installed another carburetor that Dean Oliver was kind enough to let me try. The carb was fresh, and set up for a small block, and a bit leaner than my other carb. With this setup, the miss was definitely less severe, but persisted nonetheless.

Feeling pretty confident about the state of the ignition and fuel system, I turned my attention back to the engine. I pulled the covers, and checked and reset all the valves. #4 intake was bit loose, but the rest looked good. I can't think of any other mechanical issues that would cause a miss like this.

I've got a couple of months to let the brain gears turn before I can go back to actually working on the car (damn non-heated garage), so I'd love some input regarding a good springtime game plan. We'll get it figured out eventually. Thanks

-Ben Kallies

[Greg Reimer 7376]

I thinkI'd start looking for a flat cam, especially an exhaust lobe.

[MAURICE BLENDHEIM]

Ben... I would start with a compression test. You mentioned intake lash, any chance something didn't fall into the intake manifold between the dyno and chassis (maybe paper towel or a piece of rag) I would have a look at that intake valve spring also. From what I read it is a miss load or no load. For the heck of it check it again... 1-8-7-3-6-5-4-2. Good Luck!

[Pvt Parts]

Two issues that I ran into with similar results. Super Stock Corvette.... fresh motor with engine miss. Looking at it at the track and thinking about pulling it out. I looked down and pulled on the main starter wire, the big one on the solenoid with the battery cable attached to it. It was loose, real loose like someone forgot to tighten it on install. Tightened the nut and the problem was fixed.

New Jerry Haas Comp car. Fouling plugs and killing coils in 4 to 5 runs. Chased the problem for half of the season. Finally drilled two holes in the frame tubes and ran a #10 wire from the frame tubes to each head under the header bolt. Problem fixed.

Maybe this will help. Good luck.

[Adger Smith]

You have a PM

[dartman]

Originally Posted by Ben Kallies

Dion,

I sent the carb back to Deano and made him aware of the issue. He completely disassembled the carb, and checked all of the passages. Everything looked good.

Dirk,

Thanks for the offer to help. I've got family in LaCrosse - beautiful area. Ground wires are my current focus. I'll be changing some things around even if it doesn't prove to be my problem.

Nitroman,




I plan to eliminate the vehicle wiring from the equation one way or another in the testing process. I think I'll start with what Alan suggested and run all MSD wiring straight to the battery to eliminate the rest of the vehicle wiring from the equation. If that doesn't do it, the next step is an HEI to eliminate the ignition as well. The second MSD box that I tried was brand new, and will be in retested in another vehicle this weekend or next, so that will confirm whether or not that box is good.

-Ben

have you tried a different carb?

[Adger Smith]

Ben,
I built a new engine for a customer and it missed and popped from the very first time we started it. Took it out of the car and put it on the dyno and all was fine. Changed everything in the car we could think of. The last thing we changed was the master cut off switch. We should have changed it first.

[Pvt Parts]

Originally Posted by Adger Smith

Ben,
I built a new engine for a customer and it missed and popped from the very first time we started it. Took it out of the car and put it on the dyno and all was fine. Changed everything in the car we could think of. The last thing we changed was the master cut off switch. We should have changed it first.

Now that you mention it, I've heard of that happening before.