My 19 16v cab over fuelled again?????

[Reno5gtt]

Ok, so after setting up my TPS correct my car has been absolutely perfect untill 85 miles later when it overfuelled again for a while :? I thought I had sorted the problem for good then it became rather sluggish for quite a while i.e. 4th gear at 2k foot to the floor and nothing happens it just stays at 2k :roll: the cat starts smelling really bad and there is a smell of fuel.

The only things that have not been changed on the car are ECU, coil with the ignition module, the cat and the relays in the engine bay fues box.

all the other sensors have been replaced throughout the engine bay.

A few questions...

Could the cat be blocking up every so often? I do tend to do alot of urban driving

Could the coil or ignition module be be getting hot producing a low spark every now and then?

Or could the ECU be tripping out?

Or a knackered relay in the fuse box?

Is there anyway or illiminating the components I have listed?

The other day when it started overfuelling I unplugged the ECU checked the TPS etc, set it all up plugged it back in and it ran fine the best it ever has... Does the ECU reset itself if you unplug it?

 

[Neal R19]

I had something similar with my phase 2 chammy that Jay now has, when I first got it.

You could put your foot down and it just didnt want to go at higher revs. Turned out to be the exhaust back box was blocked, put another exhaust on it and it was perfect after that.

 

[Reno5gtt]

Possibly the cat then, putting a new one on won't do it any halm I suppose. Sick of spending money on it :roll:

 

[Neal R19]

But if it's something else then the new cat will be ruined very quickly by overfuelling.

 

[Reno5gtt]

Good point... been out in it to pick the mrs up and its been ok again :?

 

[minichapperz]

well there is a possibility, but it could be further back in the exhaust thats blocked, although it shouldnt come and go, if it was blocked it shouldnt rev full stop

 

[Reno5gtt]

The whole exhaust from cat back is brand new :?

 

[minichapperz]

Hummm you are havin some serious probs, tried yankin the loom about

 

[f2 clio]

I'd gamble on fuel reg or dud injectors.

 

[Chris H]

fuel reg won't cause that, unless it totally blocks the return.

I'd either go sticky injectors or most likely a wiring issue somewhere

quick way to rule the exhaust out is to either drop it and have a look through the cat or unscrew the lambda sensor and see if it happens again.

Of course this is an issue when it may only happen every 100 miles though!

 

[minichapperz]

I cant see an exhaust blocking and unblocking itself, although the ones that ive seen is that the exhaust gases that are coming out of the back are f in hot

 

[Chris H]

depends, broken up cats can block and unblock, usualy get a tinkling sound. If you give them a thump you hear for sure.

Boxes behind that with the fibreglass (looks like horsehair) come sin long strands and it can flap about and cause a temp restriction.

But yeah super hot gasses mean a blockage, thing is they normally run ok just won't rev out and down on power.

The map/maf note the reduced throughput and adjust accordingly.

 

[Reno5gtt]

I looked in the cat and it seems intact, doesn't rattle etc... took it off and also looked at the mesh. It's been ok again today so I am just waiting for it to happen again.

I thought it might be the wiring loom (tried shaking it about, but no obvious change when idling, then again idling isn't affected when running poor) or wiring at a sensor but which one? Are there any sensors that if unplugged will give me the symtoms that I am having? If there is then I can unplug it, compare it then I may be able to track down the fault??

I am just waiting for my next pay in 2 weeks plus 3k back pay then I will start on that engine build