Ecu Problem? Maybe! Mk2 V6

[revs]

Hello all.

 

Just wondered if anyone has ever had a mk2 v6 'chipped'

 

I have tried it but so far without a great deal of success. It would appear that whilst the chip is invisible to the ecu the difference it makes isn't. The ecu has adjusted itself to compensate for all the changes made setting up the chip. (does that make sense)

 

Whilst it was on the rolling road it would appear to definetly have a second little issue. There is a drop in the power at around 4500 revs but then it goes back up again. Changed the coils and the filters but no change. Any suggestions what I change next!!

 

Any help or advice would be appreciated.

[Simply_Graham]

Hi

 

Just three things, I expect the first doesn't count if the dyno operator is good.

 

1. Make sure the oxygen sensor is up to temperature, I expect it was if you have run the car up to temp monitored and then completed the run(s) (although its been know that the big fan if a bit low scoots under the engine pan and promptly cools the O2 sensor.

 

2. You may have just have found a resonance within the exhaust or inlet system,

If you have access to the rear box, its sometimes been worth disconnecting and running a temporary flex pipe under the car and re running.

 

3. Could also be the CAT although should be affecting power from 4500 up.

 

The easy way is to change the block to a 3.2 L and change the fuel injectors to the next size up, decent Air Filter

 

225BHP (exhaust seems to be the issue) and more torque, ECU tunes its self...

 

Oh just thought of something did you check the Plug gaps, seem silly but sometime the fuleing is on the lean side and need a good fat spark, other RPM spark is good enought. (do you know if the engine was lean or rich at 4500, this may point to what the problem may be.)

 

Graham

 

P.S

Matter of intrest what was it making? The original engine in seemingly good condition was around 180BHP about 24 BHP down on manufactures quote.

 

 

 

 

 

 

 

 

 

Hello all.

 

Just wondered if anyone has ever had a mk2 v6 'chipped'

 

I have tried it but so far without a great deal of success. It would appear that whilst the chip is invisible to the ecu the difference it makes isn't. The ecu has adjusted itself to compensate for all the changes made setting up the chip. (does that make sense)

 

Whilst it was on the rolling road it would appear to definetly have a second little issue. There is a drop in the power at around 4500 revs but then it goes back up again. Changed the coils and the filters but no change. Any suggestions what I change next!!

 

Any help or advice would be appreciated.

[revs]

Thank you for your help.

 

First run before the chip it ran a peek of 198bhp.

 

The oxygen sensor should of been up to temprature as he went to lunch at this point!!! Definetely warmed when he got back!!! But I see your point with the fan they use at the front.

 

The fuel as I understand it was to rich and it was leaned off. The initial results seamed really good and it picked up at lower revs quicker. I even had an average of an extra 3mpg!! but not for long as it reverted back to its old self. But no adjustment got rid of the power dropping and picking up again.

 

The exhaust including the cat was replaced about a year ago with a stainless steel and someone has suggested that the cat could be a problem but this was in relation to its stutter (which I forgot to mention). Apparently technicaly a flat spot its at very low revs and accelerating in second gear the engine stutters. Get the revs up a bit or in any other gear its fine. It has done this though since I bought the car long before the exhaust was changed.

 

Spark plugs. Now theres an idea. They were replaced about six months ago but I dont know what was fitted. Rekon I might have to find out. Like I said not a mechanic I think your refering to the spacing at the actual spark between the 2 conductors. If I buy and fit a new set of spark plugs, decent ones obviously I assume the spacing is correct out the box and I just bolt them in??

 

Its also had an induction kit in place of the air box so that should of got it a little up from normal but 204bhp that has been mentioned somewhere as a standard car figure. If it was 24bhp down on the quoted figures then it had already almost made that up.

 

Anyway it was decided as the ecu had obviously been disconnected it had reset and to simply drive it until the ecu calms down then try setting it up again. Goes back in friday so I will soon find out about that one.

 

Just a final thought.... Old spark plugs from memory were black and oily which is a sign of over fueling possibly from what I can remember. Six months later and I assume therefore the new ones would most likely have gone the same. Think I get and change the spark plugs before friday.