EX-Engine trouble! Huzzar!!!!!!!!!!!!!

Well after 5 years and varioud set back etc, I am trying to start my car.

I have been at this for a fair few weeks now and have worked through every thing I can think of.

Current state of play.

I have fuel, every injector is opening (wet plugs)

I have a spark to every plug.

Engine is in time, at TDC rotor points to lead 1 for plug 1.

Fire order is also correct.

Engine turnes over nice and quick.

Fuel meter head flap free.

Pump running ok.

new fuel.

Now on starting the car everthing appears to be correct but it makes no effort to fire, not even a stutter!

Is there one big thing I am missing?

If it was a warm up regulator fault, duff plug, duff injector etc…..I would get some reaction.

Ideas?

Thanks

Too much fuel, leading to flooding, leading to the bores being washed with fuel and losing their compression. Take out each plug and pour a teaspoon of engine oil into the cylinder. Then disable the fuel pump and turn it over a few times. Then enable the fuel pump but disable the 5th injector.

Thanks I will try that in the morning.

Chris

I have had a go at the method you mentioned,

The engine now has made a good attempt at starting, but never quite made it. Even with the 5th injector dissconnected it isn't long untill I need to do it again.

Why would oil in the bores help with commpression(to help correct worn rings?) and why would fuel cause a loss?

Am I looking at new piston rings etc…………

The engine was a good runner before it was removed from the car and has not been tampered with.

I have carried out a commpression test while cranking the engine, now I am not 100% sure how to do a test, but this is what I did.

With all plugs out I connected the guage and turned the engine over, for each cylinder.
results below

Cylinder 1=9bar (130.5 psi) 2=10bar (145psi) 3=9bar(130.5 psi) and then 4=6.5bar(94.5psi) Now pot 4 does not look good but on a re-test of 1 and 3 I only made 8bar?

Chris

Did you keep the throttle full open while doing the compression test?

First, happy holidays  :dance:  As for your problem, I have more questions or rather comments than I do help at this point. You sound like a level headed person so maybe Internet troubleshooting might work this time.

Your compression test shows that the engine should start, maybe it will run rough as that #4 cylinder is low, but it should at least run. Why number 4 is low could be a number of reasons and I'll skip any thoughts on that until it runs and you think it runs bad.

Fuel, and oil, fouled sparkplugs don't fire well and often will not fire at all. All to often even trying to clean them does not help or helps little. I would replace the plugs with either new or good used ones before trying to start it again.

The car sat for 5 years if I understand things correctly. The 5th injector (CSV) has a direct path from system pressure and if any air is in the line will self-bleed as it is electrical. The individual cylinder injectors are 100% mechanical and if air is trapped in the lines, evaporated or just drained out, they often can not clear the air by them selves. It could be the fuel from the 5th injector only has been fouling the plugs if you have been trying for weeks to start it.

Suggestions: May or may not get you going, but this is what I would do next if it were mine.
~ As stated above - replace the sparkplugs.
~ Bleed the air from the fuel injection system (if that is whats wrong) by doing one of the following.
Easy method (also does not always work) - inject starter fluid into the intake to cause the engine to run. This could take a few tries and you need to get it to make the engine speed reach more than an idle + work the throttle to cause the air sensor plate to lift a little.
Better method (alone) - remove the rubber boot from the air sensor, hook up a jumper for the fuel pump so you can turn it on/off from outside the car, get a magnet. Now with the boot removed and the magnet stuck to the air sensor center bolt, run the fuel pump and raise the air sensor plate. This will force fuel through the injectors and you should (might) hear them pop open or squeek. With this method you will not have to dry the cylinders, replace the boot and then start the engine.
Best method (requires a helper or start button) - Same as above with the rubber boot and magnet, also the jumper for the fuel pump if alone. If you have a buddy, have him sit in the car. This time you want to crank the engine while the pump is running and you raise the air sensor plate. You may not hear the squeek/pop of the injectors due to cranking, but the engine should start and then die. You can not control the fuel by hand so it dies. Again, replace the boot and the engine should now run.

You may ask why air would cause it not to start? Fair question. When the fuel returns into the indivual injector lines it tries to push out the air but the air becomes compressed. Because the injectors require something like 35psi or more to open, the compressed air just acts like a buffer and will not force the injectors to open. If you lift the air sensor while the pump is running, the fuel pressure is incressed and enough pressure is now behind the fuel to force open the injectors. Once they pop open and no more air is trapped they have no problems.

GrimyFingers said

First, happy holidays  :dance:  As for your problem, I have more questions or rather comments than I do help at this point. You sound like a level headed person so maybe Internet troubleshooting might work this time.

Your compression test shows that the engine should start, maybe it will run rough as that #4 cylinder is low, but it should at least run. Why number 4 is low could be a number of reasons and I'll skip any thoughts on that until it runs and you think it runs bad.

Fuel, and oil, fouled sparkplugs don't fire well and often will not fire at all. All to often even trying to clean them does not help or helps little. I would replace the plugs with either new or good used ones before trying to start it again.

The car sat for 5 years if I understand things correctly. The 5th injector (CSV) has a direct path from system pressure and if any air is in the line will self-bleed as it is electrical. The individual cylinder injectors are 100% mechanical and if air is trapped in the lines, evaporated or just drained out, they often can not clear the air by them selves. It could be the fuel from the 5th injector only has been fouling the plugs if you have been trying for weeks to start it.

Suggestions: May or may not get you going, but this is what I would do next if it were mine.
~ As stated above - replace the sparkplugs.
~ Bleed the air from the fuel injection system (if that is whats wrong) by doing one of the following.
Easy method (also does not always work) - inject starter fluid into the intake to cause the engine to run. This could take a few tries and you need to get it to make the engine speed reach more than an idle + work the throttle to cause the air sensor plate to lift a little.
Better method (alone) - remove the rubber boot from the air sensor, hook up a jumper for the fuel pump so you can turn it on/off from outside the car, get a magnet. Now with the boot removed and the magnet stuck to the air sensor center bolt, run the fuel pump and raise the air sensor plate. This will force fuel through the injectors and you should (might) hear them pop open or squeek. With this method you will not have to dry the cylinders, replace the boot and then start the engine.
Best method (requires a helper or start button) - Same as above with the rubber boot and magnet, also the jumper for the fuel pump if alone. If you have a buddy, have him sit in the car. This time you want to crank the engine while the pump is running and you raise the air sensor plate. You may not hear the squeek/pop of the injectors due to cranking, but the engine should start and then die. You can not control the fuel by hand so it dies. Again, replace the boot and the engine should now run.

You may ask why air would cause it not to start? Fair question. When the fuel returns into the indivual injector lines it tries to push out the air but the air becomes compressed. Because the injectors require something like 35psi or more to open, the compressed air just acts like a buffer and will not force the injectors to open. If you lift the air sensor while the pump is running, the fuel pressure is incressed and enough pressure is now behind the fuel to force open the injectors. Once they pop open and no more air is trapped they have no problems.

So on that same basis……..if your car runs out of fuel, you need to bleed the fuel system to get it running again?

Thanks for all the help paul_c and grimyfingers.

I tested the commpression with the throttle shut. Would this cause a problem?

I think the injectors is a fair point, the injectors have not been removed from the engine at all. But the fuel supply lines have, so there is possibly some debris in there or moisture got in during the lengthy re-build.

During attempted starting the plugs were generally very wet, but since I removed the 5th injector they have been certainly dryer.

I have fitted new plugs today and as I said it very nearly ran, but sounded to be missing on one cylinder.

I think fuel injectors are to be checked next.

Chris

chriswizz said

I tested the commpression with the throttle shut. Would this cause a problem?

The readings will be too low. Do it with WOT.

I will do that, I assume the throttle open will let more air into the cylinders. Therefore more air will be compressed.

Thanks

Have you checked that when your flywheel is on TDC and the rotor arm points to No1 that both of the lobes on the cam over No1 are pointing up, ie the valve's are closed. Shows where my thoughts are on Xmas Day.

So on that same basis……..if your car runs out of fuel, you need to bleed the fuel system to get it running again?

Hmmm. To be honest, although this is a fair question, I more or less expected someone else to ask it and maybe someone like you to do the explaining. But it is very simple and will explain. Not all cars have an in tank pump, transferpump, so just skip the part about that:
Fuel is drawn from the fuel tank either via a transferpump or direct from the main fuel pump. With models with transferpumps the fuel fills a kind of holding area which is the main pump housing. The main pump pushes the fuel forward to the engine through the check valve, accumulator, filter and fuel line until it reaches the pressure regulator and fuel distributor (metering head?). Skipping all the small passages and workings of the system, it is split-up into the individual injector lines and ends up at the tip of the fuel injectors.

So, what happens when one runs their car out of gas? The fuel to the main pump is stopped because the transferpump can not supply the "holding area" for the main pump or the main pump just runs dry in models with no transferpump. Pressure falls very fast to below the opening pressure for the injectors. This causes the injectors to close, the check valve on the fuel pump to close and the push valve in the fuel distributor to close. Now whatever fuel remains in the system, called residual pressure, is trapped and remains so until the system is again under enough pressure or it drains down due to any slight leaks.

So the answer is no, running out of fuel almost never requires any bleeding off of trapped air. That said, it is possible over time or with large enough leaks to require it, but the fuel in the injector lines is almost always the last to disapear. But it could require a new fuel pump as the fuel is what cools the pump and they burn up fast without any.

I have fitted new plugs today and as I said it very nearly ran, but sounded to be missing on one cylinder.

This sounds a little different than was first explaind, or I didn't read it right. This sounds more like it does start but runs very rough and dies.

It only sounds to be "nearly running " with the starter motor spinning, without that it stops, I am going to check the compression today with the throttle open, then look into the injectors.

Decided to check each injector.

I have made a test rig at work, I have regulated our mains 8bar(116psi) air pressure down to just below 40psi, with a one injector connected I ramped up the pressure to just over to 50psi, all the injectors opened and then closed as the pressure was shut off.

So I am happy the injectors are atleast opening.

I have now tested them on the car but out of the block, and let them open individually (with the car turning over and the injector hole blocked) and each does spray.

My question is, what should the spray look like?
I do get a spray not a jet, but it does appear to put a hell of a lot of fuel out istantly soaking the inside of the milk bottle.
Would I be exespecting a fine mist?

My theory is it is severly over fueling is so what could be the possible cause?

PS, 5th injector still dissconected.

Any assistance would be fantastic.

Thanks

Chris

Massively overfuelling, is a likely scenario, simply adjust the mixture screw on the metering head to reduce it (there's no other control!) I suppose it could be due to a duff WUR, to determine this you'd need to rig up a fuel pressure gauge and measure control pressure vs ambient temperature, and compare it with specifications.

i would tow start it,get it hot if it does run,let it cool and try it again,if its bore washed,it will go off a tow
Bert

When it tries to run do you get any backfires.

OOOOps - too late…
…check your injectors with this…

Injector test (pdf)

I'm with Bert, I'd tow it and see if it starts, then you can worry about sorting excess fuelling once you know its actually going