Fuel pressure tester required

Erin · 13 December 2010, 19:23

Just wondering if anyone knows where I can get a reasonably priced fuel pressure tester. I specifically need one that connects to the schrader test port on the fuel rail in my Jeep which is suffering a loss of pressure when standing overnight and therefore needs some tinkering (probably along with a good dose of cursing and swearing that normally follows quickly during and after any reapir attempt

).

I've searched the web fairly conclusively, and all I can find is cheapo Sealey vacuum/pressure gauges for about £15 with rubber push fit hoses (no good on a schrader), or extremely pricey (£300+) commercial kits with all the adpators in the world (most of which I won't need). Can't find anything simple/sub £30 in the UK, not even on Ebay

.

Nos4r2 · 13 December 2010, 19:40

Try getting someone in the US to send you one of these?

http://www.amazon.com/Actron-CP7818-...partsreview-20

Downhilldai · 13 December 2010, 20:32

You could buy a pressure test kit on ebay for around a tenner and make up an adaptor hose using a tyre inflator connector (bicycle pump adaptor?) which will fit straight onto the schrader valve.

Erin · 13 December 2010, 21:15

Thanks Nos, that's exactly the type I'm looking for, but am amazed that there is no UK source for them.

I thought about rigging something up like Dai suggests but was a bit wary about having petrol under 40 psi spraying out if the joints failed or the rubber wasn't compatible with petrol and dissolved.

Downhilldai · 13 December 2010, 22:33

Quote:

Originally Posted by Erin

Thanks Nos, that's exactly the type I'm looking for, but am amazed that there is no UK source for them.

I thought about rigging something up like Dai suggests but was a bit wary about having petrol under 40 psi spraying out if the joints failed or the rubber wasn't compatible with petrol and dissolved.

Do it outside

40psi isn't a lot, when you consider airlines are run at 100+ psi, but take special care with petrol involved. Although the pressure is high, the volume is likely to be relatively low. Test the rig with an airline to check for leaks, before connecting it to the fuel system.

9D280 · 14 December 2010, 09:14

2.7 bar.

You probably have a length of fuel compatible hose attached to your Aux' fuel tank........

No rubber hose will dissolve that quickly in fuel.

Surely when you key on in the morning does your fuel pump not instantly repressurise the system?

Erin · 14 December 2010, 13:05

Quote:

Originally Posted by 9D280

Surely when you key on in the morning does your fuel pump not instantly repressurise the system?

If only it did. It's a common problem on Jeeps. The pump only runs for 2 or 3 seconds on eaach key turn and only does this for the first two turns of the key. After two primes it will start but still takes a while 'til pressure has built up. Problem is I don't know whether it is the check valve in the pump, the fuel pressure regulator or leaking injectors that cause the pressure loss, hence the need to run some tests with a pressure gauge.

9D280 · 14 December 2010, 14:21

You could eliminate the pressure regulator by removing it & checking it's diahpragm visually / see if it rattles (broken spring) but I would imagine if it's a Jeep problem there aren't too many people out there make regulators, so it would be a problem across more than one type of car.

Any excessive smoke on start? That might hint at leaking injector(s), as they would leave a puddle in the inlet manifold.

Erin · 14 December 2010, 17:06

I have pulled the regulator, but it all looks pretty normal, no obvious failure. It's a £50 item so I don't want to rush out and buy one just to see if it solves the problem. Also, there's no smoke on startup (in fact it's remarkably clean) so I doubt the injectors, but again a pressure tester would help eliminate the possibles. Looks like a visit to the stealer or a good independant to take a look. Frustrating really, as I always like buying new tools and sorting problems myself.