Fuel pressure problem

[stinkyonion]

I have a continuous fuel pressure gauge from the fuel rail to the dashboard. I have had problems with starting car, often 2-3 attempts, then runs fine. No CEL.

After turning off alarm, I turn key to start postion. Fuel pump cycles, but not long enough to reach full pressure, then cuts off. If I try to start at that point it usually wont. Then I turn key off and then on once or twice more, eventually fuel pressure will fully pressurize system. If I then press start key, it will start, and fuel pressure will maintain normal pressure. If I dont press start, all the pressure goes away over like 5 seconds.

I dont smell or see gas anywhere.

I would like to determine whether the leak is from the fuel pump area or the fuel rail area, but not sure how to isolate the two (assume I need fuel gauge to connect to fuel line quick connector, but cant find one at local stores). I assume likely the fuel pump area is faulty since no sign of gas. And curious what deterrmines when the fuel pump cuts off. Is it timed by the ecu or is the pressure regulator faulty and having it shut off early?

ANy ideas?

[25psi_Elise_Killer]

- Harbor Freight Tools - Quality Tools at the Lowest Prices

Fuel Injection Pump Tester

Quickly test the fuel pump pressure on most injector systems
Gauge reads 0-100 PSI, 0 to 0.7 bar
Includes flex hoses, fittings and instructions
Fits most systems (except for Bosch, CIS-Jetronic and GM throttle body systems)

[kverges]

I suspect it is a leaking check valve internal to the fuel pressure regulator or perhaps a leaking injector. Modern fuel injection systems should hold pressure, engine off, for hours and hours, if not days. Sounds like yours is not only bleedign pressure, but the fuel is actually draining back into the tank. If it is just the internal regulator module, I'd just live with it and prime the system.

[stinkyonion]

That Harbor Freight fuel gauge looks just like what I need. All the local stores just carry ones with a schraeder valve for domestic cars and no adapters. Ill buy and try and post results tonight. I saw professional ones on Amazon with a whole suitcase of adapters, but didnt want ot wait that long and they were like $200. Either way it looks like im going to miss the FVMC track event tomorrow.

Any one know what the gold colored bell thing is on the stock fuel rail? Looks like some kind of pressure related thing. New rail doesnt have anything like it. I had the fuel pressure issue before I changed fuel rails, only changed rails to get a port on the rail I could attach pressure gauge to so I could diagnose the issue.

[charliex]

that harbour freight ones doesn't have the right fittings for the elise, you can make it work especially if you've added different adapters.

they also carry the larger adapter set too, but none of them fit the elise stock fuel system either.

[25psi_Elise_Killer]

If you want to check for leaky injectors, get a flashlight and aim it at the injectors while the engine is on. Also, listen carefully for any "hissing".

I had some starting problems in my Honduh recently and thought it had to due to with the fuel system, but it just ended up being a weak battery. Check your battery voltage since that's relatively easy and painless to do while you're at it.

[stinkyonion]

I looked around the fuel rail and injectors with a flashlight, no sign of leak while running. Then I wrapped toilet paper all around the injector ports and started car for a while. The TP stayed dry. Listened carefully for leaks. Nothing.

Also checked all connectors between fuel rail and fire wall. All without leak.

Bought the harbor freight professional fuel gauge, no way to attach to elise just as charlie said. I could T into fuel line, but didnt want to have to wait for replacement fuel line so just going to return the whole kit.

So there is nothing left for me to do but remove rear liner and inspect fuel pump assembly. The probem is assuredly there.

Still wondering what that gold bell is on the stock fuel rail pictured above.

[fpitas]

My guess about the gold thing on the OEM rail is that it's a pressure/surge damper.

[25psi_Elise_Killer]

Try this, open your gas lid and have a friend put his ear against it. Turn the ignition to ON, but do not start the engine. You should be able to the hear the fuel pump prime itself.


Also check this thread since i had a few guys on here try to diagnose some fuel related issues on my Honda. The thread starts off on spark plug related stuff, but it ends up on talking about fuel problem diagnosis...
replacing spark plug wires & dielectric grease

[RCHAD]

you have a 60k dollar car and you are buying ANYTHING from harbor freight???????????????????????
sorry but after being a technician for 15 years i will never trust any garbage from public parts stores or tool suppliers!
to each his own but imho keep the garbage for the peb boys race cars
good luck

[kverges]

Harbor Freight carries many items suitable for hobbyists. My aluminum race jacks and cordless impact wrenches have been flawless for many many race seasons. Other stuff is indeed crap. For the hobbyist who checks fuel
pressure rarely the HF gauge is OK. Mine still works fine. My HF drill press I do use but only because my snaggle-tooth beaver died.