Fuel injector leaking

[geniushanbiao]

Finally I solved my '99 2.0's hard starting problem. Before it acted like this: cold start OK but not very smooth. hot start, if I start it right after shut down within a few minutes, it starts VERY good but after a few minutes, it becomes very hard to start and always needs 2-3 attempts. Also I can smell some fuel odor from exhaust right after start. It doesn't help if I pump gas and I measured vacuum it shows OK. So I believe it's not the intake system problem. The car doesn't suffer from power loss and I replaced with a new fuel pressure regulator(of course a filter) so the fuel line should be OK. I hooked up VAG-COM cable and read the data everything seems to be fine. So I suspect there were one or more injector(s) leaking. Replaced all four injectors yesterday and this morning it starts perfect. Will continue to see if it's good.

However I'm wondering if this car's injectors fail so often? It only has 116000 miles on it. I had some other cars like a 94 civic 220000miles, 02 accord 160000miles, 01 echo 170000miles all of them were using factory injector no one has any problem.

[MyOtherRidesAVette]

There is a specific diagnostic method (pressure testing of the fuel system), as described in the Bentley, to determine if there is fuel rail or fuel injector leakage. How did you determine you had an injector(s) leaking?

M.

[simonsi]

Originally Posted by geniushanbiao

It doesn't help if I pump gas

Just FYI on old carb systems pumping the gas would literally pump gas through the carb, pumping an Fi does nothing, if the ECU does or doesn't want to add fuel it will, pumping may just trigger some ECU mode if anything

[MyOtherRidesAVette]

Originally Posted by simonsi

Just FYI on old carb systems pumping the gas would literally pump gas through the carb, pumping an Fi does nothing, if the ECU does or doesn't want to add fuel it will, pumping may just trigger some ECU mode if anything

I gave up trying to explain that to ppl a long time ago, old habits die hard, I guess...

[geniushanbiao]

Originally Posted by MyOtherRidesAVette

There is a specific diagnostic method (pressure testing of the fuel system), as described in the Bentley, to determine if there is fuel rail or fuel injector leakage. How did you determine you had an injector(s) leaking?

M.

As mentioned above, I eliminated a lot of possibilities and ended up at fuel injectors problem. A lot of symptoms helped my determination. First it's the hard start problem, and after I got the car I tried to clean the fuel injectors twice(using carb cleaner to clean the lower port)after each cleaning the car started perfect for the first time, then bad from then on. Also, each time I open the intake manifold I smell a lot of gas odor from inside the intake. I think the last one makes me to believe at least one fuel injector leaking because it's not supposed to have such a big fuel odor in the intake. Also, the car is eating gas a lot(20mpg combined). Further, each time I start the car I can smell gas odor from exhaust which indicates a very rich mixture. This is also reflected on the fault codes that it has a P0172 code.

[geniushanbiao]

Originally Posted by simonsi

Just FYI on old carb systems pumping the gas would literally pump gas through the carb, pumping an Fi does nothing, if the ECU does or doesn't want to add fuel it will, pumping may just trigger some ECU mode if anything

Yes I know about this. I tried to let the car start by itself and after 3 attempts it still cannot be started I tried to pump gas a little. On other cars I serviced, if there's something wrong with the intake system(like throttle clogged or idle valve sticking), pumping gas would really help to start but on this car even if I floor the gas pedal it doesn't show any help even a little. I just wanna isolate the problem from between intake air system, fuel system and electrical system.

[geniushanbiao]

By the way, where can I get the old injectors tested? I believe there are 2 or 3 injectors still good and I wanna identify them...

[MyOtherRidesAVette]

Could the gas fumes in the intake not also be a leaking fuel rail? Would leaking injectors show up in the exhaust? Somebody...

I haven't a clue about testing injectors, try Googling "testing fuel injectors" or maybe better "bench testing fuel injectors", and see where that leads.

My shop always trys a GM additive first to clean them, but then when they tell me they're bad, I just lay down abt $1800 and replace them. (lol) I think that's what the last set cost me in a big block.

M.

[geniushanbiao]

Originally Posted by MyOtherRidesAVette

Could the gas fumes in the intake not also be a leaking fuel rail? Would leaking injectors show up in the exhaust? Somebody...


M.

Do you mean fuel leak from regulator to the intake? I already replaced the regulator with a new one and I can't smell any fuel odor from the vacuum link of the regulator right after shut down. Besides that, I can't think of any other way that fuel can be leaked from rail into intake except injectors...

[MyOtherRidesAVette]

Originally Posted by geniushanbiao

Do you mean fuel leak from regulator to the intake? I already replaced the regulator with a new one and I can't smell any fuel odor from the vacuum link of the regulator right after shut down. Besides that, I can't think of any other way that fuel can be leaked from rail into intake except injectors...

Can't answer that, Bentley simply indicates that a bleed down in pressure is the symptom of a leaking fuel injector OR fuel rail. Somebody...?

[Stlbug]

I am currious, if you have a couple of injectors leaking under pressure, where is the gas going? I hope not into the oil, that could be bad. If you are smelling a rich fuel mixture, that should'nt happen either, the EGR valve should take care of that. hummmm ,what an enigma

[simonsi]

Originally Posted by MyOtherRidesAVette

I gave up trying to explain that to ppl a long time ago, old habits die hard, I guess...

or a sign of desperation

[geniushanbiao]

Originally Posted by MyOtherRidesAVette

Can't answer that, Bentley simply indicates that a bleed down in pressure is the symptom of a leaking fuel injector OR fuel rail. Somebody...?

I think the fuel rail simply means to leak out to the air...

[geniushanbiao]

Originally Posted by Stlbug

I am currious, if you have a couple of injectors leaking under pressure, where is the gas going? I hope not into the oil, that could be bad. If you are smelling a rich fuel mixture, that should'nt happen either, the EGR valve should take care of that. hummmm ,what an enigma

This beetle doesn't have EGR valve I think....At least I can't find it.

Of course the injectors leak fuel into the intake...The injectors leak after engine shut off and this time the EGR valve is closed. And I think the EGR valve won't open until rpm is over 1500...

[Stlbug]

Ya know, I dont know if the bug has an egr valve per say but it does have a runover selenoid or some thing, anyway it 's got to have something that does what an egr valve does.

[savethebluths.org]

I know im jumping in late but your EVAP emmisions valve might be busted, it sounds like what the car does when it goes bad.

[geniushanbiao]

Originally Posted by savethebluths.org

I know im jumping in late but your EVAP emmisions valve might be busted, it sounds like what the car does when it goes bad.

Well the fact is that I replaced all 4 fuel injectors and this solved the problem completely. Now I've run over 200miles and got over 10 starts no hard start no trouble code no check engine light so far. So I think my problem is not in the EVAP system. BTW, if there's something wrong in the EVAP system the computer would set a EVAP trouble code right?

[MyOtherRidesAVette]

Originally Posted by geniushanbiao

Well the fact is that I replaced all 4 fuel injectors and this solved the problem completely. Now I've run over 200miles and got over 10 starts no hard start no trouble code no check engine light so far.

Excellent!

[Stlbug]

I guess we should be thankful that it has only 4 injectors,it could have been 5or6 or.......

[MyOtherRidesAVette]

Originally Posted by Stlbug

I guess we should be thankful that it has only 4 injectors,it could have been 5or6 or.......

Say it ... 8! As in 454 BB, been there done that!