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Ya i have checked the omh in the injectors and all is fine i could do the noid test and maybe the leak down test now when i get the kit. Thanks for the reply lads.
If I read you correctly the fuel pressure dropped off after shut down, this really shouldn’t happen as it should hold pressure in the line for some time after you shut the engine off, if it doesn’t then there could be a problem with a leaking injector OR the check valve in the fuel pump is faulty. To isolate the injectors try shutting off the engine while you have the fuel return line and feed lines pinched, this will isolate the fuel rail and if you have a leaking injector then pressure will drop quickly, if it stays constant I think we can put the fuel injector theory to rest. Lets also keep in mind that air is also important for proper engine operation and if you have any air leaks in the tube that goes from the air cleaner to the engine this will mess up the MAF reading and cause the fuel mixture to be off, the computer would not be able to pick this up either. Since the car sat for so long I think this is worth looking into. I’d also like to add that if you have a sticking IAC valve it will not allow the proper amount of air into the engine which can also cause it to stall, once again something that might not be picked up by the computer. You might try tapping on the valve with a screwdriver handle or something to see if the problem changes or goes away, if you find one here I would recommend replacing the valve instead of cleaning it as I haven’t had much luck cleaning them. Keep us posted.
Well i didnt have the fuel pump tester connected between the fuel filter and the injectors when testing it. I connected it to the fuel return line
so that would affect my results would it????????.
So decided to go at the car today.
Disconnected the fuel pump relay, cranked the engine and did not start thats normal least we know that works ha.
Reconnected the fuel pump relay, cranked it and it started poorly…..
The preasure gauge showed me the needle was jerking rising up towards normal preasure but did not reach normal preasure engine still poor.
So turned offf engine and preasure droped immeadiatly.
Disconnected the fuel pump relay and cranked engine car started perfect till it shutdown when ran out of fuel..
Reconnected the fuel pump relay and cranked engine engine ran poorly i forget now what the preasure was but i would say it was the same as the first time it
ran poorly untill about 4 or 10 seconds the engine starts to run fine and preasure builds up to normal and then when i turn off engine the preasure drops
immediatly.. So am i wrong by saying my cars gets flooded lads…..
You really haven’t confirmed that, the pressure drop is a concern because it should be able to hold pressure for at LEAST 30 min after shut down, if not there is a leak somewhere, it COULD be an injector but you won’t know till you isolate it. The drop in fuel puressure after shut off is a point of interest however and a good clue as to what is happening.
Ya well good advice their eric the car guy, the preasure is holding in the injectors after about five minutes the preasure will drop slowly very slow now and will
continue to drop and just leaving it drop away their now thats with the return line pinched.
When its not pinched the fuel drops straight away..
Now i tried to compensate the preasure gripping the return line with the vice grip adjusting it for the right preasure but not with much success as the car did
start poorly.
So does this mean my fuel pump is faulty and is it worth chancing a second hand one because i can always bring it back if it dont work and try another one
budget is tight.
Its sounding like the check valve in the fuel pump is faulty if your testing methods for the fuel injecotr leak down are correct.
Ya it sounds like that aswell to me so is it a good idea to buy a second hand fuel pump or a new one. Only then i will find out the problem at hand if it takes me
out of the woods. Although i did try to hold the preasure and start the car but did not help using a vice grip on the fuel return line or would it make any dent on the
preasure????????
Did you cross reference the testing specs from your fuel pressure test to factory specs? You wasnt very precise in stating what the KOEO PSI was.
And if you did buy a used fuel pump, you may have the same issues…
Ya thats true well my my cross referance wasnt great because my fuel measure went off calibration due to it not been able to hold the high preasure when i gripped
the return line (cheap tool) but i could manage to get readings such as when the engine shutdown the preasure would drop and build up when i turned it on
and the results were the same before it went off calibration but i could see that i think their was a drop in preasure of maybe 5- 8 psi before reaching normal
preasure
that is the car started running fine. Thats my own way of telling. But what about too much preasure would that affect the engine when i gripped the return line
with the vice grip engine ran poor. I know its not a great way to test things.
It does sound like an issue with that check valve, the only way to ‘fix’ it is to replace the pump as you suggest however. You might try starting it by cycling the key a couple of times without cranking the engine but I’m not sure if it would be able to build up pressure based on what you have reported and if that is the case that technique won’t work. Since the problem does seem to be fuel pressure related lets not forget aobut the fuel pressure regulator also, I can’t remember if it’s been suggested or not but it’s a good idea to pull the vacuum line to check for any fuel that might come out just to be on the safe side, not a bad idea to remove the vacuum line as the engine is running just to see if the pressure goes up like it’s suppose to, if the pressure doesn’t change as you might also have a problem there.
Well i disconnected the fuel regulator hose is that what your on about and watched the fuel preasure drop by 10 psi and increase when i put it
back on. I changed that regulator before but i cuold see no differance but i could put the old one back in and still replace the fuel pump anyways? Then try and
solve this problem, and i also appreciate the help im getting so far thanks………..
Also thats a good video on how a fuel pump works.
I was just thinking their my fuel gauge is connected after the regulator so this my work the opposite way??????????????? It was the only way i could hook up
my fuel gauge for readings……………………
I ve also picked up a second hand fuel pump not two sure what engine off but looks to be of spec to mine listed on the book so i mite go and take out my
own pump tommorow and try drain most of the petrol out before i do and disconnect the battery and have a look to see if its similar and if so i will swap to
see how it goes and i will be carefull because i do know it can be dangerous.
That’s not how a fuel pressure regulator is suppose to work, the pressure should go UP when you remove the hose at idle not down, perhaps the fuel pressure regulator is the problem and has been the whole time, if your readings are correct when you go to accelerate the fuel pressure will drop and starve the engine for fuel.
I think i missed sumthing you said to isolate the problem in the fuel leak i never griped the fuel return line and the feed line i just have done it now after changing
the fuel pump, the preasure is now droping very very slow but going down all the time 10 psi every 30 mins…………………………….
Oh ya happy holidays too
Even if that’s the case based on your readings it looks like you have a problem with the fuel pressure regulator, I would start there and recheck for your symptoms, if you still have them then I would look to doing the testing of the fuel pump again. Fuel pressure should go up if you remove the vacuum line from the fuel pressure regulator not down.
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