- This topic has 9 replies, 6 voices, and was last updated 12 years, 10 months ago by
.
-
Topic
-
My girlfriend has brought to my attention that when she starts her car it usually starts after one or two cranks, but sometimes when she goes to start it it will take about 2 or 3 seconds of cranking before it starts. Sometimes it happens when the car is cold and sometimes it happens when the car is Warmed up. We are both wondering what could cause this to be happening. Based on what I know about cars I would think it would be either fuel pump or something to do with the ignition or starter. The car has approximately 63000 miles. It also has the 3.1 SFI V6
-
Replies
-
Hi viper1230,
Two things come to mind. Before starting the vehicle, cycle the key to the “on” position and wait for 3 seconds. This will engage the fuel pump system. Afterwards, turn the key off. Repeat this process two more times. Once all this is completed, start the car and see if the same symptoms occur. A leaky check valve in the fuel pump delivery system could produce what you are experiencing.
Also, you may want to clean the air charge temperature sensor. This is a two-pin connector sensor that should sit somewhere in the air filter or air duct leading to the throttle bottle. Use a cleaner like electrical contact cleaner or MAF sensor cleaner on the sensor, as the housing is plastic. It is not uncommon for this sensor to get dirt and pollen build up on it, and an inaccurate temperature reading is produced which will influence the ECM and the fuel delivery system during start up.
Good luck and keep us posted.
+1 on BigC’s post.
You would need to use a fuel pressure test gauge to verify the above issue but BigC is right on a possible fault fuel pump check valve.
Also on that particular vehicle, do not rule out the fuel pressure regulator. It is vacuum operate
I checked the FPR and the is no problem with it. I haven’t had a chance to check fuel pressure. I’ll keep all of ya posted.
Here is a video that I did on ‘What’s inside a Fuel Pump’ that might shed some light on the check valve issue.
I just did a test on the fuel pressure and it read 59psi exactly when just the fuel pump was on and the pressure did not decrease and when the car was running it read 52psi, again with no drop or gradual decrease. Any other suggestions on what it could be? Thanks for the video Eric, I have watched all your videos and they are very helpful!
Some other things that come to mind for hard starting is carbon buildup on the valves, and maybe a flaky ECT sensor. Is it running properly otherwise (not rich, no hesitation, fuel consumption is normal, etc.?
I think Eric did a video showing the FI cleaning system a while back. As for the ECT, should be easy to test – just measure the resistance at various temps and make sure it’s within spec.
Ya the car runs perfectly with no problems. Just every once in awhile I will just have to crank it for a few seconds before it starts, but when it does start after the long cranking it runs perfect. Maybe the car is just being difficult lol!
The fuel pressure test that you want to do is before you crank the engine after it has set overnight, this will tell you if it’s bleeding down or not, you know it’s not an issue while the engine is running just when you start it after it sits. Another check is to try and cycle the key to the ‘run’ position a couple of times while you count to 3 to ‘prime’ the system before you attempt to crank the engine, if this works then the fuel pressure may be bleeding off due to the check valve being bad causing the long crank on start up sometimes.
- You must be logged in to reply to this topic.