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2003 Civic EX runs for 15 seconds, then stumbles and dies
Recently purchased a 2003 Civic that needed a head gasket. I've done many of these on other cars, so this is nothing new in terms of procedure. I verified timing was correct and got it all replaced and buttoned back up. The problem I'm having now is that the car fires right up, runs about 10-15 seconds, then stumbles and will die or almost die, then recover like nothing happened, go for another 10-15 seconds, and repeat the process.
Prior to the head gasket repair, I was getting a misfire in cylinders 2 and 3 which is now gone and I'm no longer losing any coolant. Prior to changing the head gasket, the car was doing this also after I pulled it home on a 2 wheel dolly. I unplugged the crank sensor connector and its very clean and no signs of corrosion and it does the same thing, but without actually dying, just runs well, then starts to stumble, and then will recover after going down to 2-3 hundred rpm.
If i flutter the accelerator, i can get it to stay running for the most part but its not happy until it dies or almost dies and then it recovers.. if it dies, it starts right back up again. I can check the fuel pressure later as well.
No CEL, no vacuum leak sounds. I've gone back over the engine and can see nothing unplugged. Oil is slightly overfilled, but not bad. I am going to change it later, but doubt that's the problem. I could buy a new crank sensor for $100 (denso), but am not sure that's the issue.
Battery is charge and easily starts the car. I triple checked the timing and its spot on with the word "up" in the correct position and the timing marks on the camshaft right at the edges of the head when the notch on the crankshaft is in the correct position.
Re: 2003 Civic EX runs for 15 seconds, then stumbles and dies
Took off the throttle body and it was pretty clean. Also took apart the IAC valve and cleaned it a bit with q tips and lots of throttle body cleaner. Plugged it in and cycled the key to the run position and validated that the IAC valve is turning and operating like it should. I'll put it all back together here in a bit and see if there are any changes. If not, I have the new denso CKPS on order and can put it in if need be. Aside from that, I dont know what else to look at. I guess I could do a compression test but it starts and sounds good. I know its putting out exhaust because its burning off the assembly lube and oil from my top end reassembly and putting out smoke.
Re: 2003 Civic EX runs for 15 seconds, then stumbles and dies
Originally Posted by slag
Anyone? I also cleaned all the grounds on the frame and engine and it didn't change anything.
It's only been four hours, we all have day jobs!
I have never heard of something like this happening before, struggling to come up with any ideas. I would definitely check fuel pressure and maybe check for an exhaust restriction. You could try swapping the crank sensor since it isn't too hard to do but I don't know if that's it. I would have thought unplugging the sensor would have made the issue go away.
You A/C compressor isn't kicking on every 10-15 seconds is it? Maybe it is failing.
Re: 2003 Civic EX runs for 15 seconds, then stumbles and dies
no, AC isn't kicking on. i can remove the exhaust manifold easily enough since I just had it off for the head and see if it runs better. I'm with you, I would have thought the crank sensor would have made the issue go away.
Re: 2003 Civic EX runs for 15 seconds, then stumbles and dies
Looks like its the exhaust plugged up. I disconnected it at the block and it ran well for a few minutes before I turned it off. So, I'm going to go hunting for a cheap replacement exhaust.
Actually, that's not true. It wasn't the exhaust. The fuel pump was going out. Once I put a fuel pressure gauge on the fuel rail, I could see the fluctuating fuel pressure. Bought a replacement pump, swapped out the internals, and its been working great for a hundred miles now.
Re: 2003 Civic EX runs for 15 seconds, then stumbles and dies
To test my fuel rail/pump pressure, I used a harbor freight fuel pressure tester kit I already had on hand. I removed the quick connects from both ends of the incoming fuel line to bypass the flexible factory hose, then used a couple sections of fuel line to splice in and clamped them to the fuel rail. the factory pump that was in there was fluctuating 5-6 psi and was jumping all over the place. The replacement is rock solid, no movement, and I gained 2-3 psi on the gauge. Car idles perfectly now.