Stalling
 

I had an issue with my cobra over the weekend that was odd, I had the car out and been trying to drive it every weekend, this past Sunday just tooling around for about 30 mins when I stopped at a light the car stalled. I was able to re-start it than got going , stopped at another light stalled again. The car runs fine at speeds but dies when stopped and just idling. The 428 has the Comp cam 294H cam with roller lifters, could the roller lifters be failing when the car is at idle(bleeding down), weak coil,...etc? The motor was running fantastic before the problem started, I was told that hydraulic roller lifters start to fail at around 3000-5000 miles (I have 4700 since the rebuild). I havn't had the chance to go over the motor and planned to do it this weekend, anyone had a similar issue?

cel,

Sounds more like something changed since the last time you drove it. Bad gas? Stuck float? A bit of dust in a carb passage? Lots of small things to check...

To your question, hydraulic roller lifters can last practically forever - hundreds of thousands of miles in factory installations. Mine are well past 40K miles and are doing fine in a 460-based engine.

If you have a carb, I'd make sure it was OK first. Then maybe the ignition?

Tom

If it were mine and it had a carburetor, the first thing I might try is raising the idle speed a hundred RPM or so to see if that helped. If it did, I'd recheck the idle mixtures and speed. My car's engine runs differently when the temperature changes a lot.

Fuel pump, fuel filter, percolation of fuel in carb......Or, perhaps we should ask what type of ignition system you have, and if you have an aftermarket control box under the hood.




Bill S.


PS: To be honest, you did not offer enough information in your initial post. Outside temp, what temp was the motor at, what carb do you have, what ignition do you have, just to name a few.

As a general rule, hydraulic roller lifters will go 100's of thousands of miles...

Solid roller lifters are the ones you have to keep an eye on.

A 294H cam is a flat tappet cam, so you don't have roller lifters at all.

The temperture was in the mid 80's the ignition box is a Street Fire with an MSD 8594 distributor, the motor was running at around 185'. As stated in the post the motor has been running great, I did take the car out on Saturday with no issues, and I did gas up that Saturday after use.

I would be looking at a fuel in the float bowls percolation possibility first.

If it is happening, you should see some visible signs of the problem with fuel boiling out the various vent tubes and air bleeds on the carb. If this is the problem, a nonmetallic spacer between the manifold and the carb can be used to isolate the carb from some of the heat and somewhat mitigate the percolation problem. The better the insulation, the better the mitigation.

These engines operate on fuel, air and spark. The air component is pretty much handled by the cam and engine displacement. That leaves fuel and spark as domiciles for potential gremlins.

If you have good fuel delivery with proper idle fueling and speed settings, and you are not experiencing a percolation issue then you are down to an ignition problem, and as Sherlock Holmes was want to say, " When you have eliminated the impossible, whatever remains, however improbable, must be the truth." You might well find the gremlin in your ignition system.

My money would first go to a percolation problem, then to idle speed and fueling, before pursuing an ignition issue. Whatever the issue is finally determined to be, my money would be on one of those with percolation in the lead.

Duplicate post

Some more info will help.
What induction system, carbs? EFI?
Gary

Fuel percolation is still a potential issue, but if the street fire box is mounted in the engine compartment, that too could be the issue. Start with the fuel filter as a simple maintenance item. Then look at the rest.




Bill S.

Stalling while braking and stopping can also be the result of a misadjusted carb float.

This is pretty much the situation with every engine that develops problems. It is not necessarily indicative of anything other than your engine not having a problem before it had a problem.


There is an amazing number of what we might call low-information/low-experience experts roaming about who are eager to share their misinformation. These two attributes, low information, and low experience are usually linked at the hip and accompanied by above-average conviction. Your belief that you were using worn-out hydraulic roller lifters is a data point that is an excellent example of this phenomenon.

If you are not experienced in working on and resolving these sorts of issues, it is to your advantage to engage the services of a reputable service provider who is and let him fix the problem for you. If you want to become increasingly knowledgeable and perhaps assume more of a hands-on type of ownership and maintenance posture, ask him what went wrong and how he fixed it. A reputable shop will give you good answers to both questions.

If none of this seems acceptable to you, we are dealing with a different situation. You have purchased a specialized vehicle that requires more than average attention to detail and maintenance, depending on how it was built and by who. You cannot provide this level of service and maintenance and are reluctant to pay for it. If this is true, you have purchased the wrong car and probably should sell it to someone else sooner rather than later.

This Ain't It, But I'll Post it Anyway
 

Had you just recently changed out your battery you would have mentioned it, so this is not likely to be your problem. But I'll post it nonetheless because there may be some guys out there that are transitioning to AGM batteries and this is not something you read about on the forums.

I hadn't had to touch my idle in years and my FE idles nicely in the low 700's. A perfect "rumpety rump." A few weeks ago I put in a new Interstate MTZ-47/H5 battery. That battery is an AGM battery, as opposed to flooded, which brought about the need for an idle adjustment.

My engine actually stalled at a stoplight on its first run with the new battery because it was idling noticeably lower. Why would this happen? Because the internal resistance of an AGM battery can be as low as 2%. A flooded battery is usually up around 10-15%. This lower internal resistance means an increased battery voltage output along with a higher amperage draw while recharging. The higher amperage draw creates a higher load on the engine from the alternator, which reduces your idle, if you have a carb. If you happen to have an aluminum flywheel, balancer, water pump, pistons, valve train, etc. then the lighter your rotating mass the more you'll notice an increased drag at idle from the alternator. A small turn of the screw fixes the problem. So, that's your snippet of information on AGM batteries for today.:cool:

When I first put my ERA on the road it stalled at stops. It has a 427 dual quad intake with a couple of Holleys that mount backwards. I quickly figured out that with the backward Holleys some changes in float levels was going to be necessary and that consisted of raising the secondary levels slightly (towards front) and lowering the primary levels slightly (at rear). Stalling issues went away after that. You probably just need to lower your secondary float level a little and make sure you have the baffle piece in the vent opening at the top of the bowl (in the metering plate). Raising your idle speed slightly might help too, if you have it set pretty low.

Its usually some gunk in the fuel mixture screws. Do what he does at the start of this video with an air hose and this trick works on all brand of carbs that have mixture screws. I fixed 2 old Ford Trucks that would constantly stall and it worked even on stock rotorcraft brand carbs. Let mw know if this cured the problem.