Re: Engine intruiges with my Disco I 4 liter SE7 1997

[wolf]

Again - I am aiming this at Joey but welcome all input;

Interesting notes here: installed my new Borla exhaust system (cat-back) and I noticed an instant pick-up in oomph and gas mileage (i.e., nearly 18.75 mpg and that was in town); however, after two tanks of gas - I seem to be headed back down to my lousy 14.5 mpg. Now here's where the voodoo gets really interesting - along with the reduced mpg - I tend to get an almost 'grand-piano-tied-to-my-engine's-ass' feeling - like it's timing has been ********. Nothing has been changed - vital stats are all the same as they come to me real time from my DashDAQ II analysis screen.

I have, as a matter of course with this elderly engine, steadily replaced nearly all the engine management sensors - from O2's, through to ECT sensor, MAF, crank sensor, intake air temp sensor, in fact the only sensors that have not been replaced recently have been the following: cam position sensor, stepper motor/idle sensor and knock sensors.

The only MIL codes I occasionally get are the same that Joey gets - i.e., concerning the catalyst below efficiency - as I have the engine's ECU chipped with Powerchips 93 Gold. (plus, I do not have any cats in my exhaust system). Incidentally, I would have thought this would have stopped my Borla gains from being tamped-down?

I still have not installed my massive AFE Universal Air-filter cannister system as that is going to require some unique engine-bay engineering, so I am still running with a K&N filter that very routinely dirties up my MAF - necessitating a clean with the appropriate MAF cleaner. I have an external air entering the engine via an ARB/Safari Snorkel and I have speculated that it tends to ram air through the K&N with enough force so as to necessitate cleaning that MAF more often (no big deal as long as I stay on top of the issue).

But the overall voodoo issue seems to be this damned tamping down of mpg and power gains that should not be happening if Powerchip USA's product does what they claim it does? Or, could this be something subtler - such as knock sensors tending to soften and thereby defaulting to a more ******** timing signal (but no MIL code)? A softening cam-sensor (but again - no MIL codes)?

I have ruled out actual spark/juice as I have had the same thing happen with two seperate coil-pak units and with superior .409 custom Race Wires from Taylor and plugs that have always worked well for me.

All thoughts and ruminations welcome.

Wolf

 

[Disco Mike]

What codes are you currently showing, why did you get rid of the cats and how?
That in itself can cause problems.

 

[wolf]

What codes are you currently showing, why did you get rid of the cats and how?
That in itself can cause problems.

Hi Mike;

Well, I still have the cats as I expect to reinstall them sooner or later but, at the time, the welder/machinist who hooked up my Magnaflow system to the new headers was not happy with how the cats affected his smooth pipe plan - i..e, from the header collectors - so we agreed that the cats would go untill I found better headers (these were Headman headers that were supposedly the right ones for the application but he had to re-engineer the darned things just to make them fit properly and he ditched their colectors as they were ugly as sin and made up his own [the only other option was to return the headers but that had become a non-option by the time I went for he install] ). In order to recognize precisley what I am talking about here - go to my uploaded e-pix as they show that work.

The occasional codes I get are as follows: PO420 Catalyst efficiency is low, bank A

and PO430 Catalyst efficiency is low, bank B


Again, Joey gets these occasionally too since he went to the Powerchip Gold 91.

What's your line of thought here - (I am interested to hear it)? Botched O2 signal(s) going to the ECU? I am all ears!

Wolf

 

[joey]

Wolf... was the exhaust a new application or is this something you did when you did the Powerchip?

I know when I did the power chip I told them I had no cats and to turn of the rear O2 sensors.

I am also looking at getting rid of my ECU and going megasquirt just so I can change what I want. Keep in mind any changes you make after the powerchip was set up for your rover will effect how the engine runs...

 

[wolf]

Wolf... was the exhaust a new application or is this something you did when you did the Powerchip?

I know when I did the power chip I told them I had no cats and to turn of the rear O2 sensors.

I am also looking at getting rid of my ECU and going megasquirt just so I can change what I want. Keep in mind any changes you make after the powerchip was set up for your rover will effect how the engine runs...

Hi Joey;

the Borla system is a new application post Power Chip - hmmmm - you have me thinking - I am certain I told them to turn off rear O2's but did I mention no cats?

By the way - what is Megasquirt?

Wolf

 

[joey]

http://www.msefi.com/index.php

One of my next upgrades.

 

[wolf]

Re: megasquirt vs LR Disco ECU

http://www.msefi.com/index.php

One of my next upgrades.

Hey Joey;

This looks most interesting but what precisley does one need to go that route: i.e., different O2 sensors? Coil-Paks? Entire sensor array replacement?

Remember, we have the same year Disco and engine - so I want to know what you are replacing as I may well follow suit.

I am very interested as well as I am fed up with the limited capabilities of chipping and, also, the LR ECU tamping down awesome gains!

over to you;

Wolf

 

[joey]

You will need to change to different O2 sensors, but you loose the MAF (woo hoo) and the ECU. Everything else IIRC will stay pretty close to the same, maybe one or two sensors. But for the cost of a MAF on the D1 you can darn near set this up.

The only down fall I have seen so far is you have to build your own wiring harness from the old ECU to the megasquirt system, but the + side it you can put it anywhere you build the harness to go, so it can be water proof in the cabin somewhere.

 

[wolf]

You will need to change to different O2 sensors, but you loose the MAF (woo hoo) and the ECU. Everything else IIRC will stay pretty close to the same, maybe one or two sensors. But for the cost of a MAF on the D1 you can darn near set this up.

The only down fall I have seen so far is you have to build your own wiring harness from the old ECU to the megasquirt system, but the + side it you can put it anywhere you build the harness to go, so it can be water proof in the cabin somewhere.

Hey Joey;

So what meters your air ito fuel mix at different temps and volumes?

Wolf

 

[joey]

it is all done via the Temp sensor, and it assumes it gets air. It may be next spring before I tackle this, but I am researching it now. Several people have done the rover conversion in the UK. Just haven't found one in the USA yet. Biggest issue I can see is building a wiring harness (I plan to relocate to inside the cabin in a water proof box).