Hi. I have a 92 Honda Acoord. When I start it (cold or hot) it runs on maybe 3 cylinders for a minute and then runs fine. I did a tuneup on it and the problem went away for a few days and now it's back. The CEL does not come on when it does this. The distributor, coil and tuneup have been done. When I start it, it will sometimes clear up after only maybe 10 seconds. Other times it take a solid minute give or take. It's very frustrating because the car is loud due to a hole in the muffler. Muffler being replaced next weekend. Any ideas? Any help would be greatly appreciated. It is currently at 317k miles. Original engine and Auto transmission. It's always had rhe timing belt and water pump replaced at regular intervals. Thanks in advance.

 

Your type of problem will require some testing to figure out the root cause. I think timing can be ruled out, because a timing belt issue would happen at all times. Is the check engine light turning/staying on when driving?

One explanation is the fuel pump check valve has failed, so your fuel rail is losing pressure when you shut off the car. Then your engine will run poorly until the fuel pump rebuilds pressure in the rail. A quick test is to turn the key to the II position, but don't turn the key to start the engine. Wait until the check engine light does the bulb test and you can hear the fuel pump turn on for about two second to pressure the rail. Repeat several times, then try starting the car. Let us know if the engine runs better or recovers quicker. You can also measure the fuel pressure. The 90-93 accords have a port on the fuel rail where you can connect a pressure gauge. The challenge is finding the right adapter to fit. I think the parts stores have fuel pressure testing kits as loaner tools that could have the correct threaded adapter. The harbor freight kit might have a proper adapter as well. I do not suggest going through the hassle/expense of dropping the gas tank to change a fuel pump unless you know you have a fuel pressure problem. You could go through all that work and not resolve the issue.

When first starting up the car, pull a spark plug wire from one cylinder at a time. Do this quickly, as an ungrounded spark plug for prolonged periods of time can short/damage the coil. If the engine doesn't stumble, then you at least figured out if you have a problem cylinder. It is possible that this is a universal issue and all 4 cylinders are contributing. If one cylinder is causing the problem, then it could be a fuel inector, spark plug, or a compression problem specific to that cylinder that you can troubleshoot.

 

@PAhonda Thank you for the info/advice. Since then, I have checked compression and all 4 cylinders are similar. They range between 192-188. I do not have a cel on while driving. I went as far as replacing 1 plug wire at a time and 1 plug at a time. I also replaced the cap and rotor. All with the same results. I will check the fuel pressure next. The old girl just hit 317K. I've owned the car since 1997. I cleaned and adjusted the fitv so it does not have the rpm surge anymore. I went as far as testing the cooling system. It held 15 psi for almost 1 hour and I figured that was long enough to determine the cooling system is sound. I'll do as you suggested and test fuel pressure. My daughter works at harbor freight, so I get a nice discount. Thanks again for the advice/suggestions. I'll reply back when I test the fuel pressure and will also try the key thing when I leave for work to see if that makes a difference.

 

I would also recommend testing the TW sensor if bad it could make car run richer than normal