I was on track at National Day in my RS1800, it has a Superchip and was revving fine right upto 6500 rpm. I was coming down the long straight and the revs were up at about 5500 when suddenly there was a kind of a pop and the revs dropped right off, also straight away there was a lot of noise from the exhaust, possibly 3 times as loud as it was.

The car is not running right and has the following symptons:

1) Very, very loud.
2) Down on power, after 4000 revs there is no go, just loads of noise!
3) Will not rev above 5000 when driving but revs to 6500 when standing.
4) It is very lumpy and blowy when idling.
5) It's using loads of fuel.

I took it to my garage believing I had an exhaust problem, they had it for the whole day, they said that the exhaust system was fine but told me a hose had popped off and they re-fitted it for £50!!! I got the car back but it was still no better.

Since then I have removed the Superchip, disconnected the battery for 1/2 an hour in case it had gone into limp mode, had a fault finding machine on it, no faults found, had an emmissions test, all fine.

The car is still not right and I really want to get to the bottom of this problem so I can sell it. I phoned my local auto electrician and he's convinced I've knackered the CAT, my local mechanic doesn't agree however. I have got a 2nd hand replacement CAT system to go on the car, but I don't want to get it changed over if it's probably not the cause of the problem.

Any ideas, help or opinions appreciated.

Thanks for reading, apologies for the essay.

 

Sounded a bit like the cat to me

 

A few people have said that Max.

 

Put your other Cat on it then!

 

yeah sounds like cats collapsed to me did it on my 2i 16 valve so i took it off emptyed the contents out and put it back on free decat lol

 

Anyone else?

 

as above sound like cat. Had the same with mine so i de-catted

 

Had the CAT swapped over yesterday.

The CAT system off the 1.6 Si is not the same as the RS1800 as expected:

https://passionford.com/forum/viewto...&highlight=cat

In fact it's actually quite different and didn't fit properly in the same space as left by the old system.

But the car is still no better, so any more ideas?

Would taking it on a rolling road help?

Any help or suggestions are much appreciated as I just want to get it sorted and it's baffling a few mechanics around here.

Thanks

 

BTTT

 

Coilpack? Common fault on the smaller zetecs with similar symptoms

 

I'll look into it.

Thanks Matt.

Any more?

 

I would have suggested coil pack. Same symtoms as a mates car. Check it for visible cracks etc

 

Afternoon squire

 

if the cat had collapsed..... surely it would have blown its load into the next silencer box and clogged that aswell.?

 

That's actually a very good point!

 

Normally in my experience if the CAT goes and blocks up the exhaust, it make the exhaust quieter but more like SSSSSSSSHHHHHHHHHHHHH

I would try disconnecting the MAF and see if it drives right - had similar fault on a 1600 Zetec mk3 Fez last week.

On those older cars if the MAF fails it generally doesn't log a fault code as it should, not sure if you realise or not, the MAF and TPS work in conjunction with each other, but if one goes down it can still run with the other disconnected, quickest and easiest way of checking them.

Suspect MAF, disconnect and see how it runs, same with TPS.

 

Had a similar problem on an old 16v GTE and that was the AFM/MAF (Air flow meter or Mass Air Flow Sensor what ever you choose to call it)

My RS1800 ran like that when I forgot to reconnect the wiring to it

 

I'll give it a try over the weekend.

Thanks guys.

 

Disconnected the MAF sensor but it didn't seem to make much difference to be honest.

What next?

The car used to do 60+ in second but now it won't go over 60 unless it's in fourth.

 

BTTT

HELP!!!!!!!

 

MAF meter.

Why not get it into someone who can watch the datastream? The fact the MAF makes no difference if you unplug it suggests its not doing much...

Also, unplug your chip until teh problem is solved, in case its that.

 

Thanks Stu.

I took the Superchip off a few weeks ago.

What do you mean by "watch the datastream"? Would somewhere like Engine Advantages be able to do this.

Cheers for the help.

 

Any good tuner should be able to do this.