Running problem (with OMEX)

[MarkM]

I have been getting an intermittent fault which is gradually getting worse.

Car seems to start OK.

I have an AFR meter so I can see the AFR reading.

When its cold it misfires and runs very rich (9.8 - 9.9 on the AFR), this seems to clear up within a minute or so.

At idle the AFR should be 14.7 but it keeps jumping down to 12.9 (too rich) then creeps up to 14.7 then jumps down again to 12.9. It stalled for the first time on Saturday when on idle it just went very rich and stopped.

On a light throttle at low revs the AFR reading seems to move about alot between rich and lean(before the problem it was stable).

When you put your foot down it is OK.

I have changed leads and TDC sensor so far, possibly coil pack next?

Was thinking maybe the lambda probe which is a wide band one for the innovate kit. But it appears to be worse when its cold and not in closed loop control. Also the meter is reading OK with no errors.

Its times like this when I wish I could just take it to a local garage to get it sorted but with the OMEX it becomes much more difficult.

Anyone recommend a specialist in the Coventry area?

 

[diamond geezer]

dont know about coventry, but i know andy at gdi knows hes stuff when it comes to omex.

 

[philthy]

I am in the same boat with taking it to a garage, they would take a look at the omex and s**t themselves.

Throttle position sensor? Does it read okay on the omex map software?

 

[franx]

think one of your lambda sensors has gone (probably the first as this is the important one)
when this happens usually the engine management (do'nt know with the Omex though) goes in some kind of emergency-cycle/run and sets a rich mixture to avoid engine damage .

could be it

 

[philthy]

try disconnecting the lambda

 

[Laura]

i know jons had a lambda go and it caused similar issues, wide band was put in and it runs sweet

 

[franx]

....
did not read your post correctly, you've already checked into lambda

 

[MarkM]

I am in the same boat with taking it to a garage, they would take a look at the omex and s**t themselves.

Throttle position sensor? Does it read okay on the omex map software?

Throttle position sensor is stable at idle not really checked it when driving, I will monitor this tonight.

Thing is every time I look at the loom it worries me.

I could do with a set of sensors to monitor and see if anything reads funny when it happens.

think one of your lambda sensors has gone (probably the first as this is the important one)
when this happens usually the engine management (do'nt know with the Omex though) goes in some kind of emergency-cycle/run and sets a rich mixture to avoid engine damage .

could be it

Possible although the OMEX doesnt look at lambda when its cold and it is worse on the initial warm up. Although it would explain why its OK on full throttle and why it hunts at idle. Problem is there is a wideband lambda probe and a control unit associated with the kit I have. I dont think I would get much change out of £250 for the hardware so I would like to be sure before I buy it.

 

[MarkM]

try disconnecting the lambda

You can set the OMEX up to stop using the lambda feedback and just run off the fuel map with no closed loop control so I will give that a go.

 

[TheJesus]

have you looked at the scatter pattern on idle?

 

[MarkM]

have you looked at the scatter pattern on idle?

What am I looking for?


It is not just idle that is an issue though.

I just priced up the lambda probe and controller for the innovate and its £160 ish

 

[ja.jack]

but i know andy at gdi knows hes stuff when it comes to omex.

Don't think going there will be an option for Mark.

 

[TheJesus]

have you looked at the scatter pattern on idle?

What am I looking for?


It is not just idle that is an issue though.

I just priced up the lambda probe and controller for the innovate and its £160 ish

not sure exactly, but when Andy mapped mine he was playing with the scatter pattern to good effect and that sorted any idle issues out... however if it's misfiring etc it could be any of the following:

air sensor
crank sensor
the other sensor I forget the name off that I replaced
lambda sensor
plugs
Omex Eprom (unlikely tbh)

Sounds like lambda fault or crank sensor fault to me though, mine did something similar.

 

[MarkM]

What am I looking for?


It is not just idle that is an issue though.

I just priced up the lambda probe and controller for the innovate and its £160 ish

not sure exactly, but when Andy mapped mine he was playing with the scatter pattern to good effect and that sorted any idle issues out... however if it's misfiring etc it could be any of the following:

air sensor
crank sensor
the other sensor I forget the name off that I replaced
lambda sensor
plugs
Omex Eprom (unlikely tbh)

Sounds like lambda fault or crank sensor fault to me though, mine did something similar.

I changed the crank sensor last week. Made no difference.

Could be lambda which I will check tonight.

Also could be coil pack which I will try if it doesnt look like the lambda.

 

[Ali]

mod'd cars, who'd have them eh!!

 

[Lagerlout]

Knowsit ^^^

 

[Dash]

Take it to a qualified Omex dealer.

 

[MarkM]

Turned the closed loop control off on the lamdba feedback and it runs fine.

Because the AFR gauge is reading OK the probe must be working so I assume the wiring back to the OMEX has a bad connection.

Cold running still seems a bit unpredictable so this must be something else

 

[philthy]

you should take the wiring apart at the original ecu and use a voltmeter to check the signals from the sensors.

 

[MarkM]

you should take the wiring apart at the original ecu and use a voltmeter to check the signals from the sensors.

The lambda is wired direct into the OMEX.

Is that what you mean?

 

[TheJesus]

you thought about taking it to a specialist yet instead of messing with it? changing things chances are you only make it worse

 

[philthy]

the lambda isnt spliced into the existing wiring? Could find out which pin it is on the omex and do the same from there

 

[MarkM]

the lambda isnt spliced into the existing wiring? Could find out which pin it is on the omex and do the same from there

I dont think so.

Its an aftermarket wideband kit. So a widband probe connects into a control unit which then drives an output to a gauge in the car and an analogue input into the ECU.

 

[MarkM]

you thought about taking it to a specialist yet instead of messing with it? changing things chances are you only make it worse

But I have found the problem. I need to trace the wiring between the innovate and the ECU. When I have done this I can turn the closed loop back on and see if it sorts it. If not I may need a new controller.

Its not rocket science

 

[TheJesus]

you thought about taking it to a specialist yet instead of messing with it? changing things chances are you only make it worse

But I have found the problem. I need to trace the wiring between the innovate and the ECU. When I have done this I can turn the closed loop back on and see if it sorts it. If not I may need a new controller.

Its not rocket science

may not be rocket science, but you've not fixed it yet have you? lol

just my opinion, I'd not want to risk it tbh, but if your happy messing then go for it lol

 

[MarkM]

may not be rocket science, but you've not fixed it yet have you? lol

just my opinion, I'd not want to risk it tbh, but if your happy messing then go for it lol

After intially slagging the OMEX off in this case it has proven to be a good tool.

I think if you have an OMEX it makes sense to at least be able to go online and monitor the sensors.

All I changed was the two circled values shown below to '0'. I have a note of the settings so changing them back is not a problem.

I think you assume I just sit there and throw values at it and see what happens. I have never changed any settings without first understanding what they are and do and more importantly making sure I record what the original values were and save a copy of the file.

 

[TheJesus]

may not be rocket science, but you've not fixed it yet have you? lol

just my opinion, I'd not want to risk it tbh, but if your happy messing then go for it lol

After intially slagging the OMEX off in this case it has proven to be a good tool.

I think if you have an OMEX it makes sense to at least be able to go online and monitor the sensors.

All I changed was the two circled values shown below to '0'. I have a note of the settings so changing them back is not a problem.

I think you assume I just sit there and throw values at it and see what happens. I have never changed any settings without first understanding what they are and do and more importantly making sure I record what the original values were and save a copy of the file.

fair enough, I'm just going off what people that map them say and having seen Andy play with mine to make it run quicker there's far too much things you can change that affect other things to warrant me messing with it. I'd have to go on a course or something before I'd even attempt to do it, get something wrong and the bill could end up being rather large

 

[stan*]

The circled figure is just an RPM parameter for lambda feedback.
If its running open-loop and its still having this fault, then you can rule out the lambda sensor and/or controler.

I'd check the coolant temp sensor next.

Or keep an eye on temp correction when its running, and see if this is yo-yo-ing.
Also keep an eye on the load value at idle and make sure this isnt jumping about.

Does the load bar move smoothly over the whole load axis when u slowly depress the throttle? (engine off, ign on, software connected obviously).

 

[ja.jack]

I'd say what Mark's trying to do is beyond the ability of most people.
I'd only get an Omex set up if I lived in Kimbolton. lol

 

[stan*]

To be fair, if youve got a bit of intelligence and some common sense, you can easily gather an idea of what does what, and the basics of whats happening.

He's done the right thing by writing figures/settings down, so that he can re-input them if it f***s up.

Obviously you dont want to start adjusting things you dont understand though.

 

[MarkM]

The circled figure is just an RPM parameter for lambda feedback.
If its running open-loop and its still having this fault, then you can rule out the lambda sensor and/or controler.

I'd check the coolant temp sensor next.

Or keep an eye on temp correction when its running, and see if this is yo-yo-ing.
Also keep an eye on the load value at idle and make sure this isnt jumping about.

Does the load bar move smoothly over the whole load axis when u slowly depress the throttle? (engine off, ign on, software connected obviously).

When I set both of those parameters to '0' (open loop) the problems go.

It has intermittently been dropping rich and stuttering but it has been gradually getting worse. Because the AFR gauge is reading OK I am assuming the probe is alright and there is potentially a wiring issue between the innovate control unit and the OMEX.

I checked coolant and throttle position sensors and they look stable when the fault happens.

 

[Dash]

What did the people who fitted your OMEX suggest?

 

[MarkM]

What did the people who fitted your OMEX suggest?

GDI?

Nothing, I havent spoke to them about it.

 

[Dash]

http://www.greydevilindustries.com/pages/contact.asp

 

[rory182]

what a ballache, cool that you can adjust it and rule things out though.

Good luck, sounds like you're on the right tracks.

 

[philthy]

Just reading up on sensors, this may help you too>

http://www.aa1car.com/library/1999/cm69910.htm

 

[MarkM]

Just reading up on sensors, this may help you too>

http://www.aa1car.com/library/1999/cm69910.htm

Thats a good overview of how it all works.

 

[stan*]

why are you running it closed loop in the first place?

but yes, sounds like a wiring issue to the lambda sensor.

 

[MarkM]

why are you running it closed loop in the first place?

but yes, sounds like a wiring issue to the lambda sensor.

Thats how it was mapped.

Its closed loop below 4500rpm and 50% load.

Since I turned it off there are a few light load sites that run lean (read over 17 on the AFR!).

I suppose if the fuel map is perfect you dont 'need' closed loop.

 

[stan*]

Personally I prefer to map the whole engine specifically. this way you have full control over getting an optimisation of power and economy.

what's your lambda target map like? see if you can get a screen dump of it up on here...