Too rich fuel mixture on 1.8 RP

Topic: Too rich fuel mixture on 1.8 RP (Read 231 times) previous topic - next topic

Too rich fuel mixture on 1.8 RP

August 12, 2024, 08:31:17 PM

I need some advice on my 1.8 RP that I have recently aquired that has a big problem. Its running WAY too rich.
When starting cold, it cranks up fine and you can hear directly its running rich, it sound like a tractor almost... And as the time goes by the idle gets worse and about to cough itself to death.
If I try to push the gas pedal down fast, it will instantly kill itself, but if I carefully slowly push it it will hesitate and slowly raise the rpm, but if I release clutch to drive forward it has very little torque for it, I need to get around 3000RPM to even get it going in 1st gear.
When warmed up it runs better, its driveable but just bareley. I can almost not accelerate and it takes ages to get up to speed, and sounds horribly rich running.
Its not smoking anything or so. No exhaust smokes.
I have checked spark plugs, they are pitch coal black, and replaced them, new ones got black within a day.
So I have replaced the blue temp sensor that apparently is normal to cause problems like this. No difference.
I have replaced everything related to ignition, wires, distrb cap, rotor and so on.
Air filter is sadly an aftermarket "performance" cone sport filter, the original air box is gone. But its fresh and clean.
I have replaced the carb flange to a brand new one, no difference.
I also did a grey area thing recently, I removed the clips for the exaust after the manifold, in order to let exhaust bypass the catalytic converter, perhaps it could be clogged. But no difference even then.
The only thing I have not replaced that maybe I should, is the o2 sensor, but could it really cause this hefty issues?
Seeking advice on what to do next!
I really want it running again

Re: Too rich fuel mixture on 1.8 RP

Reply #1 – August 19, 2024, 11:05:28 AM

When you pull the connector to the blue coolant temperature, does the idle change?
Had a similar issue with a Corrado and it turned out to be the wiring that was the fault and the car always thought it was stone cold.
The idle should change when you pull it, if not, I'd start belling the cable out.

Re: Too rich fuel mixture on 1.8 RP

Reply #2 – September 25, 2024, 02:39:41 AM

Quote from: Monkey on August 19, 2024, 11:05:28 AM

When you pull the connector to the blue coolant temperature, does the idle change?
Had a similar issue with a Corrado and it turned out to be the wiring that was the fault and the car always thought it was stone cold.
The idle should change when you pull it, if not, I'd start belling the cable out.

Not at all, but the sensor is just brand new, its very weird

Now however the idle is instead 1500 rpm when hot, and hard to start when hot, but perfect when cold

Re: Too rich fuel mixture on 1.8 RP

Reply #3 – September 25, 2024, 12:53:21 PM

Ok, pull the connector off again, then put a wire between the contacts.
If the idle changes, it's the switch, if it doesn't, its the wire.

Try it both hot and cold.