1990 90 2.3E (NG) running problem?

Posted: Tue Mar 10, 2015 8:19 pm

Hi all, back again, car still not running right, although I decided to start a new thread as the running issue is imo not related to the intermitant rattle?

Ok so, the car starts, runs for a bit then the idle dies down to about 200rpm and the car has no power and feels like it is off 3 cylinders.

When it does this, depressing the W.O.T switch seems to make the engine recover and regain full power, albeit for a limited amount of time. The whole process is repeated.

Up until the point where the car looses power the exhaust does smell a bit rich to me when I'm kicking at the loud pedal.

Related?

Any ideas?

I'm sort of making an uneducated guess and thinking lambda sensor and or MFTS?

TIA

Dan.

Posted: Fri Mar 13, 2015 6:35 pm

I have the same engine in the Coupe, which had a very similar issue.

It only used to happen when driving in the wet/damp air and it stopped after I had the fuel lines replaced.

Mechanic suggested it could have been air/water in the fuel.

Posted: Wed Mar 18, 2015 9:58 pm

Hmmm car runs fine with the differential pressure regulator unplugged.

Thoughts / ideas?

TIA

Dan.

Posted: Thu Mar 26, 2015 8:17 pm

Ok folks,

Bit of an update.

I have plugged the electrical connector back into the fuel pressure regulator.

I have found that the cold start valve has for some reason been getting a constant 12v feed instead of for ~10 seconds when starting.

I have unplugged the electrical connector from the csv.

For the most part the car has run fine, for over a week full power again has been great.

The car acts up shortly after some erm hard driving ie sustained high speed driving on a private runway Wink

When this happens the idle speed drops to about 250 rpm, power is briefly returned on engaging the wide open throttle switch.

I have then found unplugging the connector in the picture below, the car then seems to run fine again......... Can someone tell me what said connector is for?

Has anyone got any idea what is going on?

TIA

Dan

Posted: Fri Apr 24, 2015 10:07 am

Pretty sure thats for the Oxygen (o2) Sensor.

Posted: Fri Apr 24, 2015 5:20 pm

It's a while since I sold the 2.3, but that does look like the Lambda/O2 connection.
IIRC, that 2 pin plug is the heater circuit - the green wire is the actual O2 signal.

Ian.

Posted: Sat May 02, 2015 2:46 pm

thanks for replies folks.
Yep it is infact the heater wires for the o2 sensor.
I have not had the car up on a lift, but I had a new 02 sensor fitted when I had a cat bypass pipe fitted a few years back.
I'm guessing as the sensor did not come with a plug, the fitter has joined wires and they have started to short out one way or the other telling the injection module that the car is running lean, and then it is richening the fuel mixture to the point the engine wont run.
The smell from the exhaust, and the temperature needle never quite getting to where it should have really should have told me that..... Doh.
But hey, we live and learn. lol.
The car has run pretty well for the most part with it unplugged, so the next cash I have to spare, it will be replaced properly this time.
Thanks again for all your input.
Much appreciated.
Dan.

Posted: Fri May 22, 2015 9:29 pm

id be looking at replacing the metering head

Camped on the site Joined: May 10, 2013 Posts: 228

I can third that it's likely the Oxy sensor, my 2.6 has a very similar set of plugs from memory.

I'm amazed that it's made such a difference in your case, when I replaced mine they were white and the only two things I noticed was slightly more power and about a quarter better fuel economy.

Posted: Sun May 24, 2015 4:12 pm

lambda control isn't used until the car reaches a certain temp from start up.

As ive already said id be looking at a metering head fault.

I doubt the lambda sensor will be causing the problems you've described

Posted: Sat Jun 13, 2015 10:39 pm

Thanks for the replies guys,

The problem was indeed the o2 sensor, or atleast replacing it cured it.
Car going great and an 8mpg improvement in fuel consumption.
Happy for now.

cheers

Dan.