94 disco initial firing problems

[Rover3]

Well, I just got the rover back from the shop today. It now has a new starter, ignition switch wiring, and a new TPS sensor. After sitting overnight, I go to start it and it doesn't seem to fire without blimping the throttle. when it does start, it runs really rough for a few seconds and then smooths out. O2 sensors are good, has a good fuel filter, I can hear the fuel pump working although it whines quite a bit after a long ride, spark is good, no check engine light, and everything else seems to be working. Other than the starting prob, it runs great on the trail and the road, it is just the starting that is frustrating me because I have been trying to find the problem for quite some time.

Any suggestions on where I should look or things I should check would be great!

P.S. Is there any way of knowing when the fuel pump is going bad? Thank You Dweb!

 

[ShaunP]

You need to check the fuel rail pressure for leak down when the car is sitting. Could be leaky injectors,pressure reg or pump. If it seems rich when it starts the injector are leaking.

 

[Rover3]

I checked the fuel rail pressure after it was sitting for a few hours. I used a regular tire pressure gauge to check, and it registered 0 psi. I was also wandering if the plastic knob that says H on it should be tight? Thank-you for your help!

 

[ShaunP]

To prove if the regulator is leaking just clamp the spill return line back to the tank and see if it holds presure. My bet is you have a couple of leaky injectors, which flood the engine on start up.

 

[Rover3]

Shaun,
Thank-you for the replie, I'am not sure where the fuel pressure regulator is, is it the part that has the H on top of the knob and has silver rails attached to it? also, I was working with it today, and it would just turn over and over (same prob I had before I took it to the shop) and wouldn't fire for about 30min, worse than yesterday! Then something caught on and i stommped on the gas, and it finally fired up! I checked the pressure while it was running, and it read 32psi. I drove it around a while, came back, shut it off, restarted it after about 2 min, and it started with no problems! So basically, the problem is trying to get it started when it sits for a while.

Thank-you for your help shaun! greatly appreciated