I had a friend of mine who is a GM mechanic take a look at my car to find out what the problem was, he put a fuel pressure guage on it, and he told me I need a new fuel pump. But, i did the same thing, and with the key on, the pressure is 42 psi, and the engine running at idle, the pressure is 36 psi, and it does not drop. These fuel pressures seem to be in line with the required pressures for the fuel pump to be functioning properly. My problem is that my car is hard to start, usually have to turn it over twice for it to start right. If my fuel pump is functioning properly, is it possible that my hard starting problem is caused by 1 or more leaky fuel injectors? Anybody that has experience with this type of problem please chime in!

 

Could be your fuel filter.

 

Could be your fuel filter.

 

I'm also having a problem, but my car runs really rich. Just tested the pressure and it was sitting at 40 without going anywhere. It was scanned last night and one o2 sensor wasn't functioning perfectly but would that be causing me to lose over 100 miles per tank?

 

Don't think you'll lose 100 miles per tank because of 1 bad o2 sensoe!

 

The barametric pressure was a little high he said but I don't know what that is or how to change it (lol). I don't know what else it could be? If pressure is normal and its not leaking gas then what else? Already changed the filter, plugs and wires.

 

One possibility could be the EVAP canister in the driver's fenderwell. If this is malfunctioning, it could cause vapors to leak back into the intake manifold causing a rich condition. If you have a Hayne's manual, it should show you how to check it! But I hane my own problems, so anybody pleas help me out!

 

Its not throwing any codes at all it was hooked up to a Tech 2 scanner (the ***** scanner) and it showed nothing.

 

What happens to the fuel pressure when you turn off the key? It should drop only slightly on shutoff, and then bleed down very slowly. If the pressure drops rapidly on shutoff, it may be a problem with the check valve in the fuel pump. That could also be due to leaking injectors. Both conditions can cause a hard start. You can check for leaking injectors by pulling the fuel rails with the injectors still attached, and turning the key on to pressure the system (or use the fuel pump prime connection near the PCM). Do not attempt to start the engine with the injectors out of the manifold, and don't do this when the engine is hot. If the injector(S) are leaking, you will see the drips.

You also need to check your fuel pressure at WOT. Put the "test gauge" on and tape it to the outside of the windshield so you (or your passenger) can watch it while you drive. The fuel pressure should stay within 2psi of the "turn on the key" or "no vacuum" value at WOT, all the way to redline.

You can also check the pressure at idle, first with the vacuum compensation line disconnected (41-47psi meets spec), and then with the vacuum line reconnected (approx 6-8psi drop from "no vacuum" pressure).

 

If the check valve in my fuel pump is bad, and this is causing the hard starting, I know Aeromotive sells an inline check valve. If I were to install this inline check valve, could it fix my problem. Don't get me wrong, I'm ready and willing to install the fuel pump and injectors that I got, but it would be nice to find an easier way to fix it!

 

i just whent through this whole thing with my car, got the injectors professiannly cleaned(by myself at my work) new fuel pressure regualtor, and fuel pump, then replaced the number 1 injector cause it was leaking, no more problems!

 

Still interested to know if the inline checkvalve will work!