shaikhzeep

One more question,

Is there another pump inside the fuel tank?

Thanks

Hilton

Yes in an 89 there is a second pump in the fuel tank.

It could be causing a hot-start issue if the fuel system is vapor-locking between the pumps. Checking it is running is a quick and easy test:

It takes all of 5 minutes to go test the in-tank pump.

1. undo the two 10mm nuts on the cover at the rear of the fuel tank to expose your fuel filter and main pump
2. use a 7mm or 8mm spanner to undo one of the connections on the main fuel pump. wrap a bit of electrical tape around the disconnected contact to prevent shorting and blowing the fuel pump fuse in step 3.
3. jumper the terminals in the fuel pump relay position (short jumper wire between terminals 30 and 87 in the fuel pump relay scoket)
4. go back to the rear of the car where you've removed the cover, and listen for the noise of the in-tank pump running

If you hear nothing, you'll need to deal with it regardless of the no-start issue. However, I'd say from my reading of the symptoms that the issue is more likely one of the above suggestions than a non-running in-tank pump.

Stromius

Why not test the Temp2 also with a multi meter when it won't start. Each blade to chassis ground. Search forum for specific values/temperature. Each time mine behaved like this I found Temp 2 out of spec...it was very obvious. YMMV

shaikhzeep

Good day Hilton,

Thanks for your informative suggestion.I will do the test for the inside tank pump to be sure it is healthy.

Stromius , i ordered already the temp switch and i will replace it in any way.

Hopefully by replacing the above suggested relays plus the temp switch will resolve the issue.

Thanks again

SeanR

Get some fuel pressure gauges and connect them to the front right fuel rail. Run the car then shut off and then see how long it takes for the pressure to bleed off.

Had one S4 that had a fast bleed off, it had a new fuel pump and replaced the check valve just in case. That was not it. The injectors were not leaking and the FPR and dampers held vacuum. Only until I pinched the return line coming from the FPR did I realize that it was bad. Put on a new fuel pressure regulator and the problem was resolved.

WallyP

shaikhzeep,

Perhaps some explanations will help make things more clear.

Most of us think that your car is getting too much fuel (most likely) or too little fuel (possible, but not likely) when you try to start it when it is at full operating temperature. There are several possible things that can cause this problem.

- Fuel might be leaking into the intake manifold after you turn the engine off. The most common cause for this is a leaking diaphragm in one of the three devices that control the pressure in the fuel rails. There is one pressure regulator and two pressure dampeners. Each of these is located on the fuel rails that feed the fuel injectors. Each has a small vacuum line attached that is connected to the intake manifold, and each has a cloth and rubber diaphragm inside, with fuel pressure on one side, and the vacuum line on the other side. If that diaphragm leaks, fuel will pass thru the vacuum line into the intake manifold. When the engine is running, this is not really noticeable. When you shut down a hot engine, this leakage continues until all of the fuel pressure is released thru the leakage. A hot engine requires much less fuel to start than does a cold engine, and the excess fuel will make it difficult to start the engine. The excess fuel will evaporate in a few minutes in the hot engine, so the engine will start after it sits for some time. The test for this problem is easy to do. Look on the fuel rails, and find all three regulator and dampeners. Pull the small vacuum line off, and rub the open end on your finger, then smell your finger. If there is fuel smell, or any trace of liquid fuel, the diaphragm is leaking, and that unit must be replaced. Test all three units.

- Fuel may be leaking into the intake manifold from a fuel injector. This is less common, and harder to diagnose. Just keep it in mind if you can find no other cause after checking everything else. Running a good injector cleaning chemical for a few eeks will often help this. In the USA, the more expensive version of Techron, or Seafoam are good choices that are available at most auto parts stores.

The Temp II sensor is the dual sensor on the top front of the engine, in the coolant crossover, that tells the LH ECU (the fuel injection Engine Control Unit or computer) and the EZK (the ignition ECU) what the coolant temperature is. (There are two independent sensors in the housing.) The LH ECU puts more fuel in when the engine is cold, and less fuel in when the engine is hot. If the LH side of the Temp II sensor is faulty, and tells the LH ECU to add more fuel, the engine will be difficult to start when it is hot. You test Temp II sensor by measuring the resistance in Ohms between the individual blades in the sensor and the engine (never from blade-to-blade). (You can also test this at the big connector on the LH ECU, near the passenger door.) When the engine is cold (room temperature), there should be 1,4 to 3,6 kOhms resistance, and when the engine is hot (80 C), there should be 250 to 390 Ohms resistance.

- If the fuel pressure check valve is leaking, the fuel pressure will be low for a few seconds when you try to start the engine. This is more commonly a problem when the engine is cold, rather than hot. The check valve screws into the fuel pump outlet. I doubt that this is your problem.

shaikhzeep

To SeanR and WallyP ,

Thank you guys.I will check what you suggested.

Thanks

newworld

so what was followup? op?

shaikhzeep

Good day gentelmen,

Finally we found the reason for car not running from the second time.We removed the plug in cylinder 3 and we found water presence.It is head gasket gone.

We removed the heads and the head gaskets gone.The car was idle for about two years and the water got so rusty that eaten away the gaskets.

Well we are in process of building up the heads.

Will update you guys in the end results.

Thanks

shaikhzeep

to WallyP,

You are right.I found one of the three pressure regulators diaphram punctured.I replaced three of them.Also, i found one of the knock sensor leads broken and i replace it with new one.

Thanks

docmirror

Not what I expected. After your answers to my questions this could hardly have been a failed head gasket. Glad you found it and are fixing.

shaikhzeep

Good day,

Well we build up the engine heads and started the car but the engine is running smooth.If you put your hand close to the tip of the exhaust you will feel the exhaust poping and not smooth.And no power on engine.It is weak.

We checked the sparks plugs cables and everything is okay.

What went wrong?

Thanks

auzivision

When you checked the spark plug cables, did that include checking the order they were connected?

docmirror

Popping and no power is often a sign of not enough fuel(lean condition) as the engine speed is increased. Check compression with a basic tester, and you have spark, so it would fall to the air to fuel ratio is not being maintained as you rev the car higher. The air fuel ratio is determined by a lot of things and will need to be troubleshot by an expert. Check for any vacuum leaks would be a good start, then fuel pressure in the fuel rail. After that it becomes a fuel metering issue which is much more complex.

SMTCapeCod

^^ "lean" condition.

Careful when running the engine that way- likely cause it to run hot and can result in detonation that can damage the internals.

I'd suggest re-checking wire harness for the throttle position sensor and the output of the sensor itself.

Also could result from a vacuum leak, for sure.