Engine issues

Tem · October 9, 2005, 18:02

I do have a PFC, which was just fine, but seems to act up now.

When I start the engine, all seems fine. AFR is maybe a bit leaner than it used to. If I raise the revs slowly, everything seems ok for a while, but after 2-2.5k it starts to miss. If I raise the revs quickly, the AFR goes WAY down...like to 20 with a quick blib and even lower if I floor it, killing the engine.
(and by down I mean lean)

My first thought was the TPS, but PFC seems to see the values just fine. Some 0.6V off throttle and some 4V with full throttle, which seem to be the same as my old logs. Also the airflow seems to be what they seem to be on my old logs.

This came after changing the stock intake to TS turbo intake and the manifold to TS turbo manifold. I had them off for a while. I'm sure it's related to that, but can't seem to figure it out. Boost leak...? Can't find it either s:? :? s:? Any ideas?

spit · October 9, 2005, 19:02

Boost leak post-maf was my first thought, but the symptoms are perhaps too severe for that

Not familiar with the PFC but my other thought was that if you're leaning out so drastically, the PFC just isn't doing its job - could it have dumped its settings somewhere along the way?

Tem · October 9, 2005, 19:10

Quote from: "spit"Not familiar with the PFC but my other thought was that if you're leaning out so drastically, the PFC just isn't doing its job - could it have dumped its settings somewhere along the way?

That was actually the first thing I checked and it's just fine s:? :? s:?

markiii · October 9, 2005, 19:14

blocked fuel filter?

dodgy fuel pump?

Tem · October 9, 2005, 19:19

Quote from: "markiii"blocked fuel filter?

I don't think we have one...do we?
(there's one in the tank, but that shouldn't require maintenance)

Quotedodgy fuel pump?

I guess that would be possible. But would it explain why the car dies when I press the gas pedal? Even from idle s:? :? s:?

spit · October 9, 2005, 19:58

Quote from: "Tem"DOH...remove this one, thanks.

Does this mean you've solved it? or given up?!

Tem · October 9, 2005, 20:24

Quote from: "spit"
Quote from: "Tem"DOH...remove this one, thanks.
Does this mean you've solved it? or given up?!

No, just a double post s:oops: :oops: s:oops:

I meant that post, not the whole thread s8)

s8)

GSB · October 9, 2005, 21:40

You sure its not the air flow sensor Tem? The symptoms sound exactly the same...

spit · October 9, 2005, 21:43

Quote from: "markiii"dodgy fuel pump?

Possible, but a bad-luck coincidence if it is s:cry: :cry: s:cry:

Just wondering Tem, are you sure the airflow sensor is reading correctly? - not sure how you can tell if you're struggling to get through the rev range.

The only other thing I can think of (and then I'll shut up!) is also sensor-related. Maybe the PFC is performing a fuel cut due to duff boost pressure data.

Hope you get it sorted.

Anonymous · October 10, 2005, 01:39

how about swopping back to the stock ecu to see if it's the same?

Tem · October 10, 2005, 05:38

Quote from: "GSB"You sure its not the air flow sensor Tem? The symptoms sound exactly the same...

Well...I can't be sure, but it seems to give out the same voltage at idle as in my older logs and it seems to increase with revs.

Anyone here with 1ZZ+PFC? What voltage do you see when the engine isn't running, at 1000rpm and at 2000rpm without load?

Quote from: "spit"Maybe the PFC is performing a fuel cut due to duff boost pressure data.

I don't think it sees boost/vacuum anyway, just the MAF.

Quote from: "mr-s_turbo"how about swopping back to the stock ecu to see if it's the same?

Can't do that without changing back to stock injectors s:? :? s:? I guess I'll have to do that...

I did try it on without starting the engine just to see if it lights up a CEL, but it didn't.