My girlfriend's 2003 Honda CRV with 182k miles has an intermittent hard start but does not throw any codes. When I say hard start, we have to turn the key back to accessory and then turn it back to ignition two or three times before it will start. The crank sounds different when it has the hard start episode, and I have heard a clanking noise when releasing the key back to accessory after cranking the starter. Here is a bit of history.
When I started dating her a year ago, I noticed that the vehicle had a slow crank. I told her something was wrong, and she said that it had been getting progressively worse over the prior couple of years and thought it was the battery. I had it tested, and they said the battery was fine.
Over the past year, the slow crank turned into not catching fire every so often. About a month ago, the problem happened a couple of times in a week so I had the battery tested again, and now, they said the battery was bad (low amps). We replaced the battery, and it cranked quickly for about two or three days and then had the hard start happen again.
Started poking around online and found that the starter was the most likely cause. I had the starter tested, and the guy said that it was good but that he thought the problem was the starter from listening to the slow crank. He said he had seen this a few times on this model Honda. Replaced the starter. Cranks like new, but the intermittent hard start is still there and cranks slower during these episodes.
Once it finally does start during a hard crank, the engine idles rougher than usual and often dies unless the accelerator is pressed. When pressing the accelerator at a constant RPM, i.e. 3000, during one of the episodes, it misses every so often. However, if the accelerator is pressed and held at 5000 RPM's or above, the RPM's begin to rapidly fluctuate up and down. If she drives the vehicle after finally getting it cranked, it begins to run normally fairly quickly.
We can hear the fuel pump
prime when the key is turned to the accessory position, and I have ruled out a leaking fuel injector.
My girlfriend seems to think it happens more when the vehicle is parked nose uphill or on level ground but that the engine has not cranked hard with the nose pointing downhill.
I have replaced the plugs (about 5k miles ago), battery (about two weeks ago) and starter (last week). I have run Seafoam through the oil (still in there after about 100 miles) and in the gas tank during the last fill, which is at about 1/4 of a tank now. I have checked the ground from the battery to the chassis and power from the battery to the starter. Everything is tight. I have not pressure tested the fuel system or voltages because the problem is intermittent rendering any testing a waste of time unless I just happen to be testing any given electrical or fuel system component during a hard start. I can't really run around with testing equipment and hook it up every time the vehicle is cranked. It could take a year to actually hit the right component.
I have not, but plan to, replace the fuel filter under the hood and have considered replacing the EGR valve. I have not taken it to the dealership or any other mechanic because the problem is intermittent without throwing any codes. In other words, I can guess as well as anyone can and have an interest in not continuing to throw money at it.
The hard crank issue seems to have a range of potential causes from what I have read online, but I have not read any post that includes the rough idle, missing and surging. To be clear, the rough idle, missing and surging does not happen when it cranks normally.