Question for Stu - wideband llambda CVH

[ryan_gwa]

Stu, can these be fitted to MFI or only EFI? If it can be fitted to MFI set-ups would it be worth the money investing in one to try and ease fuel corrections?

 

Cheers, Ryan

 

(Didnt send this by PM, becuase it might save you getting asked again and again....)

[Stu]

I think you my be confused as to what a wideband oxygen sensor is for?

 

What are you trying to achieve?

 

(yes, the sensor can be fitted to any engine, but might not 'do' what you think it does)

[ryan_gwa]

If it was compatable with the MFI ECU, then just another way to determine when it its running lean or weak.

[Stu]

A wideband sensor would have nothing to do with either the EFI or MFI ecu.. which is why I asked what you're trying to achieve

 

 

Alternatively, state your problem?

[Craig855S]

The gwa returns!!

 

You trying to fit an air/fuel guage?

[ryan_gwa]

A wideband sensor would have nothing to do with either the EFI or MFI ecu.. which is why I asked what you're trying to achieve

 

 

Alternatively, state your problem?

 

Stu, my problem is I dont want to convert to EFI, because I would rather keep the car as close to original as possible (to a degree).

 

But MFI is prone to incorrect fueling, so im just researching what options there are to resolve this. Obviously a good working metering head and a decent set-up would cure this, but are there any other ways?

 

The gwa returns!!

 

You trying to fit an air/fuel guage?

 

Scoop, Im out in KAF at the moment, but when I was back on my week off I decided to buy an 88' ERST, was a spur of the moment really. Getting bored of Impreza's now, sold my green one the other month, the silver is tucked up in my garage for the winter.

 

No, I'm not trying to fit any guages, I'm not an expert on CVH's by any means! First time I have owned one.

Edited September 16, 2010 by ryan_gwa

[Stu]

Stu, my problem is I dont want to convert to EFI, because I would rather keep the car as close to original as possible (to a degree).

 

But MFI is prone to incorrect fueling, so im just researching what options there are to resolve this. Obviously a good working metering head and a decent set-up would cure this, but are there any other ways?

 

Okay so you first of all need to establish if your fuelling is out? You almost sounded as if you wanted to interface a wideband sensor with mfi/efi systems, where it would actually be a seperate standalone unit.

 

Do you know you have an issue? If not I probably wouldn't worry about it until you notice something (eg poor fuel economy, black smoke, rough running). MFI is pretty good, but it is old now and can fail (usually runs lean).

 

If you don't own a wideband oxygen monitoring kit, perhaps borrow one from someone as a temporary measure? Avoid stuff that goes in the tailpipe though as these are often inaccurate and will be thrown out seriously by any slight exhaust leaks you may not be aware of. An oxygen sensor should be mounted in the exhaust after it merges into a single pipe.

 

You'll need to get a sensor mounting bung welded into your downpipe if you don't have one already!

 

 

I just re-read your comments, so this is an ERST? Really you need to set the base fuelling on a gas analyser and then test it out on the road with a wideband to make sure its not running lean.. probably best to let a tuner do it?

[ryan_gwa]

Stu, my problem is I dont want to convert to EFI, because I would rather keep the car as close to original as possible (to a degree).

 

But MFI is prone to incorrect fueling, so im just researching what options there are to resolve this. Obviously a good working metering head and a decent set-up would cure this, but are there any other ways?

 

Okay so you first of all need to establish if your fuelling is out? You almost sounded as if you wanted to interface a wideband sensor with mfi/efi systems, where it would actually be a seperate standalone unit.

 

Do you know you have an issue? If not I probably wouldn't worry about it until you notice something (eg poor fuel economy, black smoke, rough running). MFI is pretty good, but it is old now and can fail (usually runs lean).

 

If you don't own a wideband oxygen monitoring kit, perhaps borrow one from someone as a temporary measure? Avoid stuff that goes in the tailpipe though as these are often inaccurate and will be thrown out seriously by any slight exhaust leaks you may not be aware of. An oxygen sensor should be mounted in the exhaust after it merges into a single pipe.

 

You'll need to get a sensor mounting bung welded into your downpipe if you don't have one already!

 

 

I just re-read your comments, so this is an ERST? Really you need to set the base fuelling on a gas analyser and then test it out on the road with a wideband to make sure its not running lean.. probably best to let a tuner do it?

 

The fueling is most definetly out, runs very rich. The car pops and bangs out the exhaust on the very slightest bit of over-run. Can smell unburnt fuel at the exhaust tip. Also, although not really a metering unit or map fault, is the cold start.

 

Engine lets this car, not physically wrong, just the usual RS Turbo problems by the sounds of things.

 

The idea was to get it set-up by a proper tuner, I havent got enough knowledge of mapping to attempt it myself. Probably make it worse.

[Stu]

Well you can't map it... the fuelling side.

[ryan_gwa]

Just adjust the metering head to suit what map it has?

[Stu]

It doesn't have a map for fuelling.. it's mechanical fuel injection.. it does have fuel enrichment for cold start though..

[ryan_gwa]

Sorry, meant to match the fueling to the boost setting. Think mine has some sort of chip, but not been near it long enough to pull the ECU out.

[Stu]

MFI doesn't work like that. You have two ECU's, one for fuel, one for spark control. When you chip an MFI car, you either replace the chip in the spark ecu (the aluminium one) or do a MAP sensor clamp hack (eg MSD).. depending on the chip it'll either simply remove the boost limit allowing you run more boost, or if it's a decent chip it'll also have a new spark table in it..

 

Neither affect the fuelling..