Rep Power: 0

I have a 2004 Honda Civic EX coupe. Sometimes it takes three attempts to start the car but then runs fine. I did a fuel pressure check on a new aftermarket fuel pump. When I prime the fuel pump it reads 40 psi. When the engine is started at idle it goes to 45psi. When I shut the engine off it goes back to 40 psi right away. If i wait about 20 minutes it goes to about 37psi. If i let it sit overnight it goes to 5 psi. Could this cause the hard starts? I had the same problem with another new aftermarket fuel pump, I noticed it had a different style fuel pressure regulator. It seems to me that 40 psi, primed, should be enough to start the engine or maybe not. Appreciate any suggestions. Thanks

 
Rep Power: 222

If you leave the key on for like 20 seconds before starting does it start ok?

 
Rep Power: 0

If I recall , I think I tried that before and it didn't matter. I decided to install a new fuel pressure regulator today. I'm going to test drive the car tomorrow and see if it starts better. Since I disconnected the battery I'll have to do the relearn process. If that doesn't work I'm thinking maybe I have a weak camshaft sensor. I've read that they can get weak and the ecm has to take over and correct the timing without throwing a code. hat's why the long start. The sensor is a Honda that I bought off ebay. I'll get back to you tomorrow.
Thank You

 
Rep Power: 222

Hopefully the sensor isn't a fake. Don't throw out the old sensor

 
Rep Power: 0

Well, installing the new fuel injection pressure regulator didn't help. I tried the 20 second starting procedure and it worked one time , then didn't the next. I forgot to mention i did an engine swap with a JDM engine. It's suppose to be the same, but maybe a little more horsepower. The original fuel pump worked okay with the old engine but not with the newer engine. It finally went out so I tried two new aftermarket fuel pumps. With the new fuel pressure regulator I just installed this makes a total of four regulators. So I doubt this is the problem. The engine sounds like it's out of time. I think I will pull the camshaft sensor connector and check the voltage then I'll have to take out the sensor. I wish now I had gone to the Honda dealer and bought one from them. When the engine was out of the car I went and changed the timing belt along with the sensor. I probably should have left the original one in there. Anyway , it will be awhile before I can get to it but I'll get back to the forum if I find out anything. Appreciate your input. Thanks

 
Rep Power: 222

Check timing before you throw more parts at it

 
Rep Power: 0

Will do. What I don't understand is that if the engine timing is off, how can the engine runs so well after it starts. Can the ecm make up for it and to what degree. Anyway, tomorrow I think I will check the camshaft connector voltage before I tear into the engine. One step at a time.

 
Rep Power: 0

Well, problem solved. I saw this You tube video on my particular engine, the 1.7, The mechanic claimed that aftermarket camshaft and crankshaft sensors will not work on this engine. They have to be genuine Honda sensors. So I went to the dealer and bought both sensors , it cost me plenty but it was worth it. The engine now starts like a new one. Now I can move on to other issues with the car. Hope this helps someone. Thank You