General Fuel rail pressure testing.

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General Fuel rail pressure testing.

I did the same test as you, these are my results.
The Mode Test 3 100 Impulses 3.5 ms.
Press the petrol pump 49 psi.
Fuel injector is IWP 116 from a Punto 1.2
 

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I did the same test as you, these are my results.
The Mode Test 3 100 Impulses 3.5 ms.
Press the petrol pump 49 psi.
Fuel injector is IWP 116 from a Punto 1.2


Hi pandablu,

Thanks a million for your test results.Would it be safe to say that the three

paragraphs represent

Pulse 1 in the first paragraph

Pulse 2 in the second paragraph, and

Pulse 3 in the paragraph. I hope I have this right.

I only used pulse 1 setting across the 4 injectors.

If I have this right, then comparing my results and your results in column/

paragraph 1 I'm losing around 5 psi, and your results show around 10 psi.

It would look like my injectors could be slightly blocked and need cleaning.

At this point I don't know the exact model of injectors installed, and to be

honest never really looked. Even though the car goes like a bullet further

investigation is needed, and if cleaning does bring my readings closer to

yours pandablu, then things can only get better.

100 mph..................UP the HILL!!!!!

Will you confirm for me pandablu when you get a chance, that I'm reading

correctly your test results. Making comparisons between same engines

really helps out. Thanks pandablu.
icon14.gif


John.
 
Hi pandablu,

Thanks a million for your test results.Would it be safe to say that the three

paragraphs represent

Pulse 1 in the first paragraph

Pulse 2 in the second paragraph, and

Pulse 3 in the paragraph. I hope I have this right.

I only used pulse 1 setting across the 4 injectors.

If I have this right, then comparing my results and your results in column/

paragraph 1 I'm losing around 5 psi, and your results show around 10 psi.

It would look like my injectors could be slightly blocked and need cleaning.

At this point I don't know the exact model of injectors installed, and to be

honest never really looked. Even though the car goes like a bullet further

investigation is needed, and if cleaning does bring my readings closer to

yours pandablu, then things can only get better.

100 mph..................UP the HILL!!!!!

Will you confirm for me pandablu when you get a chance, that I'm reading

correctly your test results. Making comparisons between same engines

really helps out. Thanks pandablu.
icon14.gif


John.

Hi,
I would not rely too much on pressure drop as an indication of injector flow rate. There are too many variables including trapped fuel volume and elasticity of flexible pipes. The fuel trim values will give you a better idea if flow is close to what the engine ECU expects the injectors to deliver. Only way to check for sure is to pull the injectors and squirt a known number of timed pulses into measuring cylinders and visually check the spray pattern (with fire precautions).


Robert G8RPI.
 
I did the second test. The device in Mode 2. In the first test it was in Mode 3.
 

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Last edited:
Hi,
I would not rely too much on pressure drop as an indication of injector flow rate. There are too many variables including trapped fuel volume and elasticity of flexible pipes. The fuel trim values will give you a better idea if flow is close to what the engine ECU expects the injectors to deliver. Only way to check for sure is to pull the injectors and squirt a known number of timed pulses into measuring cylinders and visually check the spray pattern (with fire precautions).


Robert G8RPI.

Hi Robert G8RPI,

I see where you are coming from alright. The ECU is the brains that make the

settings, which include injector pulse width. And as you say, if pulse width isn't

enough it'll just keep them open longer next time round.

But as you also point out, removing the injectors would confirm the condition

of the injectors for spray pattern and so on. It may come to that yet must have a

cup of coffee and make the decision.

Thanks Robert for the advice. One can never know everything all of the time.

John.
 
I did the second test. The device in Mode 2. In the first test it was in Mode 3.


Hi pandablu,

Your second test on Mode 2 looks very consistent....100%.

I take it your car is running very well? With those figures I'd be surprised

if it wasn't. I also take it under quick acceleration you have no hesitation,

stumble? Responds well.

As Robert points out the ecu will make corrections where needed.

Looking at a good few utube videos with guys using the fuel injector tester

at Pulse 1 setting they expect to see a pressure drop of around 10 psi.

Very much like the readings you're experiencing...........on the ball as they say.

Do you use the tester often and on other makes of cars?

I ask because you'd see the pressure drop readings on a different range of

engines.

How did you overcome the connection to your schrader valve, or am I

missing something obvious. Don't worry pandablu..............something could

be staring at me and I still wouldn't see it!!!!

I've only used the tester once as it only arrived a little while back, so I

might not be fully up to speed yet. But getting there.

Thanks pandablu for your test results, nice to see how others are getting on.

John.
 
My car works on LPG and the problems were with the flow of LPG
injectors.The car goes well,accelerating well.
I have some problems with the timing belt,i do not know how to adjust it.
I removed the schrader valve with a copper pipe 6 mm diameter.
 

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Hi pandablu,

That was a sneaky move with 6mm copper pipe then notch the end to suit the schrader

valve. Why didn't I think of that,and I thought I was smart, seems to me I can learn a trick

or two from your good self.



Did you manage to sort your problems with the flow of lpg? And if so, how did you

overcome your problem? Can you adjust the timing belt.............I didn't know you

could. You learn something new every day. The diagnostics are nice and clear

AC stag, I use multiecuscan free version at the moment, but it gets me by so far.

Being nosey...as I am.... looking at some of your readings, I notice lambda 1 is at

0.79 volts.................is that a little rich pandablu, or am I translating the reading in the

wrong? When you have been driving vw classic beetles for the last 30 odd years

diagnostics are a new area for me to get my head around. Like everything else....getting

there. You really need the diagnostic tools to make things easier to understand, and if

can master stft and ltfts you're 90% in making a proper diagnostic conclusion.

Thanks pandablu for the details of your tests, and the AC stag readings.

Have to tip off now, I have a 92 fiat ducato 2.5 non turbo weinsberg camper to get going

systems are slow cranking. Got battery and starter checked and both are 100%.

Thought I might have a current draw................but NO.............alls ok. Might be an

earth/ ground issue. Then one of the family arrived with a 2003 fiat doblo 1.2 petrol

battery was flat first thing this morning, got it started with jump leads. I got out the

multimeter and checked for amp draw, and sure enough there was ....1.34amps.

Have to locate which circuit is the culprit, and put it right.

Chat you soon and thanks for your post pandablu.

John.
 
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