TII - no power

tsh · June 29, 2009, 10:16:18 PM

I\'m nearly back... Been doing some tidying up ready to get my turbo II back on the road, and I\'ve discovered that what seemed to be an intermittent problem seems to be more permanent

Engine is stock, except for exhaust (no cat), and not done a lot of miles since replacement 5 years ago. Starts no problem, and sometimes drives fine. At the moment, once i get above 3000 rpm, i get a complete loss of power - feels like the ignition can\'t cope with the fuel. Actually, it\'s not the rpm, it seems to be manifold pressure related. Negative pressure, it\'s fine. As soon as pressure reaches 0, the power cuts out - making it impossible to maintain more than about 50mph on the flat.
I tried disconnecting the air pressure sensor - no change.
I tried cleaning the earthing connections - no change.

Short of swapping out all the parts for spares (already done the coils), does this ring any bells, or anyone got any other suggestions?

thanks,

sean

grinder · June 29, 2009, 10:58:39 PM

to be honest i have no idea - but i havent seen you around in AGES - so welcome back

could it be a faulty FCD ?

Prof · June 29, 2009, 11:44:25 PM

It might be worth checking for fault codes as this sounds a bit like \'limp mode\' which may indicate a failure of one of the sensors.

pdtaylor18 · June 30, 2009, 01:22:45 AM

Also make sure you intercooler hoses are all done up,I had something very similar.

Brett · June 30, 2009, 08:30:04 AM

It\'s also worth checking the wiring to your fuel pump :wave

Welcome back!

pdtaylor18 · June 30, 2009, 08:48:35 AM

Brett you reminded me of a fuel pump issue i had on a non rotary car a few years back and that was a fuel pump,ok at idle but as soon as you wanted some right foot it would cut out but this one seems a bit more specific. Apart from checking that everything is connected correctly and that includes plugs,hoses,earths etc then it may only be a case of swopping stuff out. It should not be any of the emissions stuff so leave that for now so you need to concentrate on the main culprits:

ECU
Fuelling- FPR, pump, clogged filter
Ignition- coils, TPS

tsh · June 30, 2009, 09:06:52 AM

TPS is something I\'ve not checked (and have spare). Can I check the fault codes without a special tool? (I never managed to find the instructions anywhere). ECU swap is planned too.

Don\'t think it\'s limp mode, it\'s too dangerous at junctions!

sean

Prof · June 30, 2009, 11:23:32 AM

Quote from: tsh;621336TPS is something I\'ve not checked (and have spare). Can I check the fault codes without a special tool? (I never managed to find the instructions anywhere). ECU swap is planned too.

Don\'t think it\'s limp mode, it\'s too dangerous at junctions!

sean

No special tool - just a light or LED is all you need:

See this thread for how - incidentally - this may be your problem described here:

http://www.mazdarotaryclub.com/forums/showthread.php?t=49131&highlight=ecu+codes

Grizzly · June 30, 2009, 12:23:05 PM

Does it still have a Cat on? and does it rattle at all?

tsh · June 30, 2009, 12:53:21 PM

No, no cat. Not much rattling...
I was wondering if it might be a faulty knock sensor, since it does feel a bit like overboost. Looks like the check light is simple, will give that a try.

Speedworks · June 30, 2009, 02:34:04 PM

I have exactly thesame problem with my FD at the moment. I already changed coils, fuel rail, improved grounding wit extra wires, checked TPS position.
Engine idles fine but starting around 3000rpm there is a light tremble.. sort of fuel starvation or iginition prblem (though my wideband reads good AFR\'s)

My engine has all emissions removed (PFC ECU) BUT My Knock sensor isn\'t reading on the PFC; Could that be a problem? (refering to faulthy sensors)

Maybe the sensor thing is the way to go?

tsh · June 30, 2009, 02:39:10 PM

Doesn\'t sound the same, this isn\'t a slight tremble, it\'s a complete loss of power, like the ignition is cut (even worse than running on one rotor as I\'ve had with a 1st gen and a broken dizzy) - and it only happens under load, not whilst stationary - makes diagnosis kind of hard... I\'m tempted to change things or fake sensors just to see what I effect.

grinder · June 30, 2009, 03:59:24 PM

i had that once ( but im sure it was fuel cut ) - felt like i drove into a brick wall

can you redline it if you stay off boost

tsh · June 30, 2009, 07:00:32 PM

Quick update - 27,30 33. OMP and 2 solenoid valve emissions thningies. Have spares of all, so will have a play tomorrow...

Prof · June 30, 2009, 10:00:42 PM

The OMP code will defo put you in limp mode - which will give that top end power cut you are getting.

The 2 solenoid errors don\'t affect the engine running in limp mode