Engine Mechanical problem
1995 Oldsmobile Cutlass 6 cyl Two Wheel Drive Automatic
The car will crank with plenty of power but refuses to start. The battery is brand new and the connections are tight. We replaced the spark plugs and wires and checked that each one is firing.
We also replaced the fuel pressure regulator. Once we did so, the car ran great for two days and then suddenly behaved as though it was out of fuel. It would start, run about 10 seconds, and then sputter and die. Hoping that the gauge was wrong, I put in 5 gallons from a can. After two tries, the car started and I made it home. However, as soon as I turned it off, I attempted to restart it with no luck.
I tested the fuel pump relay and verified that it is working. I can not find if there is another fuse related to the pump. When I turn the key on, I can not hear the pump building pressure. At the time we replaced the regulator, we were following the recommended procedure to relieve the pressure in the fuel system by removing the relay. However, this had no apparent affect and the car continued to run. We had to disconnect a wiring link next to the fuel pump before the car finally ran out of gas on it's own.
We had a similar problem a week ago but the car finally started and we took it to a shop. They tested the fuel pump and told us the pressure was adequate. However, both the shop and myself have been unable to change the fuel filter because of how rusted the connection is to the fuel line. The shop said the filter should be fine for now. However, the car will not start at all now.
Use PB Blaster on connections that will break loose the rust so you can change filter but I would like to know what the pressure is at the fuel rail before you change filter and after you can go to autozone and they will loan you a fuel pressure guage and you can test this your self the location is on top of fuel rail no. 3,4,5 on diagram
January, 31, 2009 AT 11:03 PM
That is one of the few details I left out of my original message but I have already sprayed the fuel filter nut with PB Blaster several times with no improvement. I will try once more but honestly at this point, I don't believe I will be able to break it loose without damaging the fuel line. I have already been told that my only source for a replacement line would be at a junk yard.
What will the pressure readings tell you?
February, 1, 2009 AT 10:59 AM
There are 3 things you need for an engine to run 1-fuel / pressure 2-spark 3-compression I need to see if fuel pressure is strong enough also you can get a spark tester from auto zone or any other parts store (they're only about $5.00) it looks like a spark plug with a clip on the side you remove #1 plug wire and insert the test plug and have someone crank engine over and look for spark and lastly you ckeck for compression on all cylenders you can also borrow a compression tester from autozone if you get the compression tester let me know and I will talk you through testing
February, 1, 2009 AT 10:19 PM
Before replacing the fuel regulator, my friend helped me test the spark by pulling off each spark plug wire at the coil while I tried to start the car. At that time, all six were firing.
On a side note, I have gotten down by the fuel tank while someone turned the key on. Even with a screwdriver to my ear touching the tank, I can't hear a thing in the tank. I'm wondering if the pump has failed.
I will check into the compression tester.
February, 2, 2009 AT 9:21 AM
Ok you have spark thats good now we need to check fuel pressure since you cant hear the pump and compression fuel pressure Turn the ignition ON and check that pump pressure is 24-40 psi. (165-276 kPa)
Start the engine and allow it to idle. The fuel pressure should drop to 28-32 psi (193-221 kPa) due to the lower manifold pressure, please let me know reading on fuel pressure and compression also here is how to test compression
a screw-in type compression gauge is more accurate that the type you simply hold against the spark plug hole, although it takes slightly longer to use. It's worth it to obtain a more accurate reading. Follow the procedures given: Warm up the engine to normal operating temperature.
Tag the spark plug wires and remove all the spark plugs.
Disable the fuel and ignition systems.
Remove the air cleaner assembly and fully open the throttle plates by operating the throttle linkage by hand or by having an assistant floor the accelerator pedal.
Coat the gauge threads with oil and screw the compression gauge into the no. 1 spark plug hole until the fitting is snug.
Be careful not to crossthread the plug hole. On aluminum cylinder heads use extra care, as the threads in these heads are easily ruined.
Ask an assistant to depress the accelerator pedal fully. Then, while you read the compression gauge, ask the assistant to crank the engine two or three times in short bursts using the ignition switch. There should be four puffs per cylinder.
Read the compression gauge at the end of each series of cranks, and record the highest of these readings. Repeat this procedure for each of the engine's cylinders. Compare the highest reading of each cylinder to the compression pressure specification. The lowest cylinder reading should not be less than 70% of the highest reading. Examples follow: NORMAL: Compression builds up quickly and evenly to the specified compression on each cylinder.
PISTON RINGS: Compression low on the first stroke, tends to build up on the following strokes, but does not reach normal. This reading should be tested with the addition of a few shots of engine oil into the cylinder. If the compression increases considerably, the rings are leaking compression.
VALVES: Low on the first stroke, does not tend to build up on following strokes. This reading will stay around the same with a few shots of engine oil.
HEAD GASKET: The compression reading is low between two adjacent cylinders. The head gasket between the two cylinders may be blown. If there is the sign of white smoke coming from the exhaust while the engine is running may indicate water leaking into the cylinder.
If a cylinder is unusually low, shoot about a tablespoon of clean engine oil into the cylinder through the spark plug hole and repeat the compression test. If the compression comes up after adding the oil, it appears that the cylinder's piston rings or bore are damaged or worn. If the pressure remains low, the valves may not be seating properly (a valve job is needed), or the head gasket may be blown near that cylinder. If compression in any two adjacent cylinders is low, and if the addition of oil does not help the compression, there is leakage past the head gasket. Oil and coolant water in the combustion chamber can result from this problem. There may be evidence of water droplets on the engine dipstick when a head gasket has blown.
February, 2, 2009 AT 10:54 PM
I went to both auto zone and checkers but neither of them offer a fuel pressure gauge. I am still working on getting the filter off with no headway.
I bought a can of starter fluid and sprayed a bit in the air intake. The car started for a second so I am more and more convinced the problem is fuel.
As far as the compression test, how do you propose I do that since the car won't start, which I mentioned in my first post? It did run at the time we replaced the regulator and I got it home from the grocery store but since that day, it has not ran at all.
February, 3, 2009 AT 9:42 AM
You do not want the engine running when you pull a compression test it states that in my post telling you how to do the compression test as for the fuel filter you may be forced to change the line all you'll have to do is cut the line abiut 3 inches from filter and get a coupler thats fits the line and buy a new line about 1 foot long and using coupler install new line and filter just make sure you get a line the same size and has the same connection for the filter
February, 3, 2009 AT 9:22 PM
Well, first the good news. I took your advice and was able to replace the fuel filter by cutting the line and patching in a segment. It proved to be a tight fit because the fuel line makes a 180 degree turn right after connecting to the filter. I will have to monitor for leaks.
Now the bad news. The car still won't start. After hooking everything back up, I wondered if I left the filter unhooked at one end and turned the ignition on, should I get a stream of fuel? I tried it and got a pathetic dry response. So, it appears as though the pump has gone out. My only remaining line of hope is whether there is a fuse for the fuel pump. The only relay I found that was under the hood on the passenger side has tested ok. Is there some other fuse for a 95 olds or anything else I should check? I am certain the tank has gas.
Unless you have any other suggestions that can confirm/deny that the pump is bad, then I will be towing the P.O.S. To the shop and have them drop the tank.
February, 3, 2009 AT 9:36 PM
Ok under the rear of car near top of tank you will see a wire connecter going to fuel tank unplug and then turn key to on see if you get power to that point if you do then the fuel pump is bad if it shows to be bad then let me know and I will send the removal and install for you
February, 4, 2009 AT 11:19 AM
I know the connector you are referring to and will try to test it tonight. What voltage should I expect with the key on - 12V?
The first time we had to relieve the pressure on the fuel system before changing the regulator, we ended up disconnecting that wire coupling. When the relay was removed, the engine continued to run so we searched for another way to kill the engine and just by chance, I noticed that connector.