Integrator value very low! Ideas?

[Sparky]

Hi chaps

Got a real nutty one at the moment. This SE Runs rough as a badger's arse, integrator sits around 60-70, BLM 128. Nothing apparent on other data streams. Apparently greater men than I have tried to fix this, to no avail. I've done a fair bit already, but would like to hear any suggestions without yet telling you how far I've got! Someone might just come up with a wild idea that I haven't thought of...

[internets]

Question, I think I have asked before but can't remember, what chip is he running? If he has an S4s or updated chip, I remember reading something about differences with VE tables between the SE/S4s which can possibly cause issues. Can't remember exactly what though?! Just a thought

If he has a non standard SE chip maybe try swapping out for stock SE code, resetting the ecu and taking for a good blast to re-learn?

[Sparky]

S4s chip mate. I know of one other SE running S4s with no probs, though. When's my chip guru back from hols?

[internets]

Yes, I know one or two SE's running S4s code with no problems also

I have a feeling it was something Mr Espritmon (Erik) himself had an issue with so maybe he can chime in

Not sure when he is back....,I am Back Saturday lunch time so can pop over in the afternoon if needed

Edited August 12, 2012 by internets

[Sparky]

Starting to suspect it's not engine management now, so manifold is off.

[fsrowsell]

I think you need to check the resistance in the O2 sensor. When I had a bad O2 sensor. It would bog out on the motorway. I would have to pump the peddle to get it back again. I know you are not getting a code for the O2, just the same!

In deed it is a mystery!

Good luck mate, I know to will figure it out or die trying...

[Sparky]

Trouble is, mate, it's had 5 O2 sensors in 8 years (the right ones too)!

[internets]

Wiring fault?! Give the power probe a big workout

[Sparky]

My power probe hasn't had a good workout in years :-(

[internets]

What is this, Carry on Watford exotics?! :-P Ohhh matron

[Vulcan Grey]

I'm guessing no codes are stored?

Have any logged Freescan data?

Were you plotting BLM or BLM vs BLM Cell?

Fuel pressure is what?

Different injectors or are they stock?

[Sparky]

Ah, Mr Grey, I've been expecting you.

Hopefully you'll be able to crack this one. Injectors standard, some logged data somewhere in my email (I'll find and post it) but I couldn't see anything glaringly obvious. Only looked at live data yesterday, BLM static at 128, cell at 19, integrator around 60-70 in closed loop. Will check fuel pressure when manifold's back on.

History - been like it for 8 years. Successive specialists have been at it, after which it runs for 100 or so miles without apparent issue, then reverts. I had it in a few months ago, found the min rate screw had been played with, brought the IAC down to acceptable levels. Car ran fine, again for approx 100 miles, then reverted.

It idles very rough, bogs down at throttle up, loses power under load at around 2500rpm, and standing still won't hold 2500, but drops several hundred rpm rhythmically. O2 never makes it down as far as 0.2.

Things done so far:

Swapped ECU with known good

5 O2 sensors across the years!

Swapped fuel press regulator with known good

TPS changed

Crank sensor may have been changed, not sure.

IAC swapped with known good

Valve clearances OK

Valve timing spot on

Manifold currently off just to eliminate possibility of minor leaks.

That's it, I think.

Forgot to add - Throttle body linkage screw shows evidence of having been adjusted, and 1/2 are open a few thou when 3/4 appear closed. Of course, I only found that out once I'd stripped it. Might be a contributory factor...?

[Vulcan Grey]

Have you swapped MAP sensor, or looked at electrical connections to the MAP? Also the hose integrity to MAP.

[Sparky]

Checked hoses, no problem. Haven't swapped MAP though! I'll give that a go when she's back together, thanks.

[fjmuurling]

BLM value of 128 is the perfect value for a BLM Cell, 19 is a BLM Cell when the engines idles. The ECU uses different BLM cells depending on RPM & MAP.

I agree with Travis about changing / checking the MAP sensor, hoses and wiring.

About using a (modified) S4s Chip in an SE all I can say is that the VE tables for a SE and a S4s are different. The ECU/Software will adjust the various blm values if the wrong tables are used but then the system will be operating out of the sweet spot.

The 100 miles you mention is that a cumulative distance (more runs) or a single 100 mile run?

[Sparky]

Cheers. I'm happy with BLM and cell, it's the integrator that concerns me! 100 miles is an arbitrary figure - it could be several runs, 2 weeks, whatever, but it always reverts to poor running.

[SteveSmith]

As someone who knows a thing or two about this problem car, I know I mentioned it previously but forgot to mention it again on Saturday, there is a crack in the plastic elbow for the pressure line going into the MAP sensor.

I know the MAP data is reading OK but maybe, just maybe, fiddling with the pipe around the elbow seals it enough to run well for a couple of weeks but then degrades ??

Really wish I'd remembered to remind you of that on Saturday...

May be just another red herring of course

[Trevsked]

Now THAT is funny. Can't wait till Sparky reads it, wsih I could see his face.

Trevor.

[Sparky]

Sorry to disappoint, Trevor. Already checked that, and despite a minor crack it's holding vacuum fine. :-P

[Bibs]

The MAP line is positive pressure isn't it, that could be expanding a crack?

[SteveSmith]

Oh - was really hoping the running issue was all down to that crack in the elbow

Worth swapping out anyway ?? Can't be a *good* thing to have a crack in your pressure line...

[Sparky]

Rest assured pipe integrity is fine :-)

[Trevsked]

Sorry to disappoint, Trevor. Already checked that, and despite a minor crack it's holding vacuum fine. :-P

That's a shame, could have laughed about that one for ages :-).

Trevor.

[Sparky]

Hehehe. In fact, yes, it is worth changing. Couldn't get too verbose earlier - was in a heavy meeting.

[Mike6]

Sounds to me that it needs a good tap with one of my dads heavy (and I mean heavy) duty hammers courtesy of london Transport. Works a treat on carb turbos.