Compression and injection testers ?

[John Doe 2Participant @johndoe2]

Hi guys,

 

I am seeking recommendations for test equipment for my car: a good cylinder compression tester and also a comprehensive fuel injector tester.

There are many of both on the internet, but these days, without seeing them first, you have no idea if they are any good, or are just “toy” ones.

Some brands that I used to trust are now shadows of their former selves, and I want to avoid those.

I would prefer to buy quality test gear once, rather than cheap and nasty toy test gear multiple times.

 

Many thanks in advance.

[noel shelleyParticipant @noelshelley55608]

You have given NO details as to the engine type. For compression tester – make one ! A pressure guage and suitable means to attach to the engine. Since we don’t know the fuel type so injection testing are we talking about diesel injection ? Noel.

[Howard LewisParticipant @howardlewis46836]

If you make a compression tester, you need to incorporate a tyre valve assembly at the engine end, to act as a non return valve, to retain the reading.

The tip of the valve stem needs to be accessible, so that the pressure can be released before taking the next reading.

Ideally the connection needs to be retained in place. You will have difficulty holding the tester in place with compression pressures above 120 -130 psi, on a petrol engine.  So a sparking plug body will probably need to be modified.

Either way, buy or make, not likely to be cheap.

And measure the pressure after the same cranking time, say 10 seconds, so that results are comparable.

For a diesel, you will need an injector body that can be modified, and the compression pressures will be high, of the order of 500 psi for an engine in good condition.

With regard to an injector tester, presumably for a Diesel, the gauge will need to read to quite a high figure.

20 years ago breaking pressures were 210+bar, and with emissions regulations tightening almost yearly, may very well be higher.

Howard

[Andy StopfordParticipant @andystopford50521]

I’ve got an Injectester which I’d sell, but, it is only suitable for old-school mechanical diesel injection.

https://archive.commercialmotor.com/article/16th-december-1960/58/new-injection-and-compression-testing-equipment

[DiogenesParticipant @diogenes]

https://www.toolbee.co.uk/sykes-pickavant-33100000-universal-digital-pressure-tester-comprehensive-kit.html

[bernard towersParticipant @bernardtowers37738]

servicing fuel injectors is NOT for amateurs.

[John Doe 2Participant @johndoe2]

Who said I was an amateur ?

My car is petrol and my apologies, I meant electrical indirect injectors, running on about 2.5 bar fuel pressure.

So a “normal” cylinder compression tester that will screw into a spark plug hole, and measure and hold the maximum compression reading. I do not have the means or the time to make a compression tester, and even if I did, I would still be asking for a known decent make of gauge, i.e. a medium to highish quality pressure gauge that is robust and will last.

You can get gadgets to fire injectors a set number of times to check their delivery and spray pattern but without burning out the electrical coil.

And while we are at it, a good quality make of fuel pressure gauge as well.

I can google things myself, but as I say I want known good quality rather than taking pot luck. Some brands that used to be good quality no longer are, and I am simply trying to avoid that sort of thing, by relying on the combined knowledge on this forum.

 

 

[noel shelleyParticipant @noelshelley55608]

for gauges I use WIKA and what Howard decribed is exactly how I made one in the early70s and I still use it. 0 – 300 psi gauge 100mm dia. An old plug body, a tyre valve, flexy brake hose(withw wire protector) and the gauge. The same gauge will work for your fuel pessure. Noel.

[Pete RimmerParticipant @peterimmer30576]

You can hold a 12v injector open with a 9v battery without causing damage. I’ve wired them open and stuck them in an ultrasonic cleaner to clean them before.

[DiogenesParticipant @diogenes]

..S-P would be straight where I went if I wanted ‘pro’ workshop tools  / diagnostic equipment..

..but I realise what you asking; Sealey are (at least until recently) probably a more reliable buy than much of the cheaper opposition – I think they still try hard to keep a finger-hold in the independent / small-business ‘pro’ market place.

 

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