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I looked at info for 3.1L vinM Buick regal. fuel pressure key on engine off, 40.5--47 psi. Can you check the vin? The fuel pressure specs I have for 3.8L engine are even higher than the 3.1L.
You will get a fuel pump prime, key on engine off. You need to make sure fuel pump runs with engine cranking.
My hearing is no good, I can't hear fuel pump with engine cranking.
Sometimes If fuel pump brushes are bad, the fuel pump may run intermittently. Sometimes you can bang on bottom of gas tank when trying to start and the fuel pump will take off running.
No. it wouldn't keep it from starting. If the engine cranks but won't start, probably gas or spark (ignition) related. Do you hear the fuel pump in the tank turn on for a couple of seconds, when turning key to on, not start? If you cannot hear the pump, better check if you are getting gas up to the engine. Maybe the fuel pump quit, or the pump circuit needs looked at. The pump should briefly turn on with key on to pressurize the fuel system-the fuel line and the fuel rail where the injectors are. Then the pump will turn off, and only come back on again when the engine is cranking, and stay on when running.
Correct fuel pressure is important for easy starting, and good engine performance. Have the fuel pressure checked against the specification for your vehicle. If fuel pressure is good, check the ignition system-check for spark.
no starts. cranks perfectly, full cranking speed, not 1 rpm but nearer 300.
ever do the 60k tuneup in the book.?
assuming the service was done and all cyl. are over 150PSI (WOT)
then we check spark first, not fuel..
The ECU brain cuts fuel (by design) any time spark is gone.
here is the proper flow:
1: throw, wild guess?, compression is good,. cam belt slip??????
is cam shaft turning,? look down oil fill hole. is it?
2: i check spark it's bad. (fix spark)
2a: i check spark its good', on all 4 cylinders not just 1.
3: spark was good. cam spins, pray compression is ok....
4: i connect scan tool, i crank for 5 seconds and see RPM rise ,good
i see ECT at say 50f (garage temp) and might see DTCs get thrown as i crank? , i see P0340 or p0355 ( one is dead CKP and other is CMP)
in my case no DTC thrown cranking , and i have spark and ECU
communicates. (key point) we alway s do that ,the tool is $9 (ask)
5: i then look at spark tips, they are:
1: soaking wet, its flooded, (spark was good but they are 10 year old.
2: dry, no fuel all spark tips day.
your engine has 4 cylinders, and all four most not flood or run dry.
i can listen to any cold start and hear gross misfire. but.....
if they are bone dry, i check voltage to the fuel pump.
it must be 12vdc cranking , 1/2 the cars you must crank. to get the pump to run ,(ECU hard logic!)
say I have 12vdc cranking
i check he fuel pressure, its not 30psi, its 5 psi (bad)
i rap the side of the fuel pressure regulator and it now is 30psi.
car starts. the reg was stuck wide open(its bad)
ok, still no start. or good pressure. Good is 30.
let say it was 60psi, i find i forgot to replace my dirty and packed up fuel filter
at the 60k mile service point. ( did i save $10 ? , no)
pretend filter is good..... pressure way low.... (examples)
so i read my FSM and it shows this shunt test, i then block (pinch)
the Fuel return line at the Fuel press. regulator.
i see 60psi, the pump is good. (do only for 5seconds ) (2 man test)
i see 10psi, the pump is bad ( of i have 12v at pump cranking,.....)
all this are pump tests there are 6 tests. not counting the injector balance test.
this is my order you can do it backwards, but will most the time have to start over, and cuss a $200 pump change , in vain.
here is the scotty way.
wont start, spark is good, tuneup done. sparks all 4 are wet
this is called flooding, the operators guide, says.
crank with the throttle open (WOT) car starts, it was flooded.
can happen in N.Canana (especially summer fuel in tank)
now car runs find and fresh fuel , 10 x better.
if no , post car keeps flooding, we can work that too.
is fuel pressure at 60psi, bingo, ask.
The crank sensor is a good candidate. Pretty common failure on jeeps. To clarify, the fuel pump is on all time during engine cranking, and during engine running. When the engine cuts off, the pump will also be stopped. But, you will not lose pressure in the fuel lines and fuel rail immediately. The check valve in the pump is supposed to hold fuel pressure in the system for a good time-about 20 minutes. The pressure should bleed off very slowly.
Your fuel pump and fuel system is probably good, but if you really lose prime (or pressure) that quickly, then there is a problem. Best way to check is with a fuel pressure gauge after the engine cuts out. Or, if you have the test port schraeder valve on the fuel rail (looks like a tire valve), you can use a screwdriver to press the center of the valve. If gas squirts out, you do have fuel pressure, prime is not lost, fuel system is good, and you can assume problem is in the ignition circuit, not a fuel problem. Probably the crank position sensor. Good luck, Casey.
I think you've identified your own problem. In your description of the problem, you indicate "no fuel pressure on rail".....
First things first, try replacing the fuel filter. If this doesn't do the trick, make sure the fuel pump is actually pumping (you indicated that you hot wired it with a 12 volt DC supply and it ran). Running is one thing....pumping fuel another. To properly identify issue you need to know the cranking fuel pump pressure. If you can get it to start it would also be a very good idea to check out the fuel pressure regulator.
When you turn the key to the "ON" position (don't crank it, just to to the position where it would run) do you hear a few seconds worth of pump motor activity?
If it tried to start when you introduced fuel into the breather, then I think it's safe to say you have some sort of fuel delivery issue.
You need 3 things.
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors.
You may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start. Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems. One test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem. Run the full fuel pressure test and post back pressures. Here is the guide lines on testing.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Also you mentioned that you replaced the fuel pump, it's common for the $15.00 wire harness from the fuel pump to the frame will break and there is a bad connection till the wires heat up. You can try this trick, turn your ignition on for 30 seconds "engine not running" and then turn it off for for 5 seconds and then try to start. This will energize the fuel line if the fuel line check valve is bad which is a part of the fuel pump and will heat up the wire harness which will make a better connection and see if the engine starts easier. Regardless, inspect the wire harness for corrosion and the ground is good. Good luck and keep me posted.
you have pressure bleedng off due to a bad check valve in the fuel pump or a bad pressure regulator (on the fuel rail) letting pressure bleed off.
When you turn the key on & off, it starts the fuel pump for 2 seconds each time. The pump turns off after 2 seconds unless the engine is running. The pump runs all the time during crank mode.
But you need 40 psi when you start cranking so the injectors can spray fuel into the cylinders.
please rate as fixya if this identifies your issue. Good luck.