Engine: 2.3 F/Inj Purge check valve needed

[Luxobarge]

OK, so had another fiddle this morning, I checked that all the vacuum lines from the TCV are going to the right place, and they are, so that's all good.

I then removed the main air pipe near the throttle body and checked it for damage - there was none, it looked in good nick.

I then located the second purge check valve and removed it - handy, as it's under the intake pipe that I removed above. This one worked fine, would only pass air in one direction as it should, so I decided to re-use it. Some of the purge system hosing going to it was pretty crusty, so I replaced that with nice new stuff and re-assembled it all.

I did notice a small vac line going from the inlet manifold to the TRV was pretty crusty too, I think it's 5mm and I haven't got any, so when I do I'll replace that too, although I don't think it's actually causing a problem at the moment.

Haven't driven it yet, but I'm quite sure there will be no difference. I think my next step will be to fit the boost gauge when it arrives so I can see exactly what's going on, and measure the magnitude of the problem (if any).

Thanks again for all contributions to this thread. Cheers

[sdg1970]

Originally Posted by Pupbelly

Correct, that's the one I mean. I can't see how this would affect any running issues but is potentially on the list to replace once everything else is sorted.

Yap, I've just checked that on mine and I used generic hose (5mm I think) I got from a local motor factors. It's fuel grade stuff, so over and above OEM spec.

[SteveSarre]

Sorry, quickly trying to catch up.

Vacuum hose diagrams may vary between models so make sure you use the appropriate diagram. (Not sure if T5 is different from LPT).

While I remember, there is a solenoid on the LHS of the radiator which controls vacuum in the hose that goes to a cylindrical tank beneath the LH front wing. One could call that a purge valve (it purges fuel vapours from the fuel tank).
The valve is a bit similar to the TCV valve, but not the same AFAIK.

I investigated that at some point because lying underneath the car I could hear a putt putt putting sound every few seconds. The L-shaped vacuum hose was split near the tank. I replaced that with some normal silicone vacuum hose of an appropriate diameter and the putting stopped.

I don't think it had any affect on running, but probably better that the fuel tank gets purged than unfiltered air gets sucked into the engine.

HTH
Steve

[Luxobarge]

OK, update: The boost gauge kit arrived today, so had a go at fitting it. Took me most of the day! I got it from PFV, and also got the mounting binnacle that goes on the driver's side A pillar. This needed a LOT of fettling with a dremel to get it to fit decently, it's basically made to a generic shape and I think you're expected to cut/shape it to fit the profile of whatever A pillar you have. Got there in the end though, looks OK.

To get the vacuum hose into the engine bay I found a short crinkly tube about 15mm diameter going through the firewall right next to the throttle cable, with a rubber cover over both ends. It was empty, so I fed the tube through there and re-used the rubber end covers to keep water out - it's in just the right place, and could have been put there specifically for this purpose - result!

The vac hose they supply isn't long enough to get to the vacuum tree, so I used a length of thin cunifer brake pipe to extend it, the hard pipe runs under the aluminium cover for the fuel injectors, quite neat and solved the length problem.

One problem with the gauge is that the glass comes in a trendy "smoked" finish, which means that without any back-lighting it's virtually impossible to read, even in daylight - duh! So instead of wiring the instrument back-light to the lighting circuit I wired it to an ignition switched live, so the back-light is on all the time that the ignition is on. It's nice and easy to read like that.

So does it work? Yes it does, and I think that it does indeed tell me I've got a problem. The gauge markings are in bar, and I believe I'm right in saying that I should get around 0.65 bar (9.5psi) under acceleration and 0.75 bar (11psi) under maximum acceleration for a maximum of 30 seconds. I only did a fairly short test trip but the most I could get was 0.5 bar, which equates to about 7.2 psi, which I think is well short of what I should be getting. This tallies with my perception that the car does get a move on when you hoof it, but not as lively and startling as it should be.

So, it's boosting but not as much as it should. Where do I go from here? Any ideas? I still have a couple of vacuum hoses to renew, but although the old ones are a bit crusty I very much doubt that this is the cause of the problem. Should I just shorten the actuator a bit, or is this silly? Remember it has a brand new Pierburg TCV, so you guys with experience do let me have your ideas as to what to do next. Thanks!

[sdg1970]

A standard, non-mapped 97 T5 should boost to 10psi as I recall. If I'm wrong I'll stand corrected, but I'm pretty sure it's 10. My 97 R has an MTE map and it boosts to 15psi on max acceleration.

Perhaps you could list what you have done to try and remedy the problem and then we can all go from there. Without reading the entire thread, I assume as a starting point all turbo and intercooler hoses have been replaced?? Also, when you come off the pedal after hard acceleration (and I mean hard!) are you hearing any noises??

[Luxobarge]

Originally Posted by sdg1970

A standard, non-mapped 97 T5 should boost to 10psi as I recall. If I'm wrong I'll stand corrected, but I'm pretty sure it's 10. My 97 R has an MTE map and it boosts to 15psi on max acceleration.

Perhaps you could list what you have done to try and remedy the problem and then we can all go from there. Without reading the entire thread, I assume as a starting point all turbo and intercooler hoses have been replaced?? Also, when you come off the pedal after hard acceleration (and I mean hard!) are you hearing any noises??

Thanks for that - confirms that it's not boosting as hard as it should. So basically actions have been:

1) All turbo hoses and vacuum lines checked and/or replaced (there are a couple still to do but they're not that bad and I really don't think are causing the problem).

2) New Pierburg TCV fitted, and checked that vac lines from it are going to the right places.

3) One of the valves in the purge system (which is connected to the main vacuum system) was faulty, so replaced this.

4) Fitted boost gauge, showing max 7.2psi (0.5bar) indicating the magnitude of the problem.

That's all so far......

No, not hearing any noises when I come of the pedal after hard acceleration.

Thanks!

[sdg1970]

Personally any hoses on there that are still original then I would definitely be replacing them. They can be very good at disguising any small splits that occur and more often than not it happens just in the spot out of sight. I'll assume your bottom intercooler hose is in good shape as that one gets a lot of stick. Intercooler itself OK?? These can crack, but it's rare.

I guess you could give your waste gate arm a tug and make sure there's good resistance on the spring, or in fact that it's free-moving. These should have a fair amount of resistance under finger pressure. Also when you say Pierburg TRV, do you mean the TCV on the side of the air box?? I fitted a Forge Motorsports uprated TRV which also gives a bit of extra performance.

I'll also assume the little vac elbow above the alternator on that end of the engine is in good shape??

[Luxobarge]

Sorry, I meant Turbo Control Valve, TCV, now edited. The TRV on the turbo itself looks original, but looks a pig to get off with the turbo in situ, otherwise I'd be inclined to put a Forge one on as you have. How difficult is it?

Yes, I'll be replacing the two remaining crusty vacuum lines as soon as I can, I agree it HAS to be done, of for no better reason than to eliminate them and also prevent certain problems in the future.

I'll check the other things you mention, haven't looked closely at the elbow or the lower intercooler hose yet.

Thanks!

[sdg1970]

To be fair, the elbow is always the one thing that causes many woes, but you usually get a myriad OBD codes too when that splits. Worth checking though!!

The TRV can be replaced with the turbo in situ. There are three allen screws holding it in place, two of which are easy to get out, one (on the left side as I recall) not so easy, but certainly doable.

[SteveSarre]

"To get the vacuum hose into the engine bay I found a short crinkly tube about 15mm diameter going through the firewall right next to the throttle cable, with a rubber cover over both ends. It was empty, so I fed the tube through there and re-used the rubber end covers to keep water out - it's in just the right place, and could have been put there specifically for this purpose - result!"

That tube is used for LHD cars. Go across to the passenger side and look in the same place on the firewall. I cant remember what that side is used for. But as you found, that tube is a useful route through the firewall.

Steve