Low rev hesitation

[Simon_16v]

Hi Guys,

Over the last couple of weeks I've had a problem where the car seems to hesitate around and under 2000rpm whilst under load. I'm not sure if it's just a coincidence but it also seems to do it a bit more since I've fitted a decat?

Any idea what it could be or where to start looking first to try and solve this issue?

Thanks,

Simon

 

[JPJ89]

I'v read people on here before saying low down hesitation could be a lambda sensor issue mate, I had the same problem for a week or 2 but strangely enough it disappeared without me actually doing anything, beginning to wonder if I have a bad earth somewhere causing intermittent faults, only reason I can think of for it coming and going! Hope you get it sorted, sure someone will be able to help out with a better answer lol!

 

[Simon_16v]

Anyone?

 

[imprezaworks]

Try re fitting the cat?

 

[Simon_16v]

I'm not sure how the decat could be causing it? There's only the post-cat lambda and with a spacer there is no emissions light on?

 

[imprezaworks]

It could be a faulty sensor and coincidence

 

[imprezaworks]

Ignore that. It could be something daft like, have you changed where you get your petrol. Plugs, could ok?

 

[warwickstingray]

I'd replace the cat to rule that out. Only costs time where as parts cost money.

Removing an restriction of an old 400 cell cat I'm assuming a 172 here as I'm on my mobile and sticking a Decat in there will have messed with fuelling just about everywhere which is why some people don't recommend them without a remap of some discription.

You risk being out of the scope of the standard map with a change like that.

 

[imprezaworks]

Si has a 182 iirc. Has the car been mapped/rs tuned?

 

[Simon_16v]

Yeah I've got a 182 and it hasn't been mapped as far as I'm aware.

 

[imprezaworks]

If you keep the cat stick a tuner map on it. Problem solved I reckon. The car will be running rich at the very least at the mo

 

[imprezaworks]

Decat I ment not the cat

 

[Bear Head]

@Simon_16v it needs a remap buddy.

You're really playing with the fuelling etc so you need to map it

Getting mine done in a couple of weeks at RS Tuning because I'd like some power runs anyway.

Mine feels exactly the same, bit of hesitation low down as I've just fitted a new sports cat. It's f**king tiny compared to the original without all the restrictions etc.

 

[Simon_16v]

The hesitation was there before fitting the decat though.

Swapped the lamda sensors over this afternoon and hasn't made a blind bit of different. Unplugged various sensors on the inlet and also made no difference.

Removing the inlet manifold tomorrow and checking the condition of the plugs and hoping to find something here.

 

[KitsonRis]

Mine has similar problems, like a hesitation when accelerating from low revs in 4th. I had a dodgy connection on on of my plugs. Also happened to my stepdad when he owned the car before me and he changed an injector as that was faulty.
So try the connections to the plugs and the injectors.

 

[Simon_16v]

Just an update.

Took the inlet off last night/this morning with the hopes of seeing a dud spark plug or the likes. After removing them all they looked fine but I did notice they were Bosch plugs, after being told when I had the belts done in 2013 that the ones in were wrong and the specialist had then fitted the 'correct' ones. But disregarding the plugs, I didn't find anything wrong and then just it all back together again and then went for a drive and no more hesitation . God knows what was causing the issue but I feel it may have been a connection somewhere but I'm glad it's working fine again.

Luckily I've got some proper plugs coming from @George@RTR_Parts which I'll fit during the week and then maybe some new HT leads after CSS.

 

[leeds_182]

Result.

I've decatted loads of my cars without a map and there has been no issue. The only one I had an issue with was my 197.

 

[Bear Head]

Result.

I've decatted loads of my cars without a map and there has been no issue. The only one I had an issue with was my 197.

When I put a sports cat and straight through midsection on my car I noticed a flatspot but thought nothing of it.

Had it mapped and looking at the initial dyno run, I was right! Pretty ginormous flatspot looking at the graph!

 

[Tommyd22]

I had this problem when my timing was out but had the belts etc re done and it was fine after

 

[Ex-User (107751)]

A thought about the hesitation ,
You can hear the air induction on\off when it occurs on my car. If there was a spark problem/fuel supplement problem, the air induction would sound consistent ?
If so, it can only be timing ? can't be the throttle as it works perfect after 3000 rpm .

 

[leeds_182]

Hope you get this sorted for CSS, bro!

 

[steviekyle13793]

@Bear Head - How much are you looking at for a few dyno runs and a remap?

 

[Bear Head]

@Bear Head - How much are you looking at for a few dyno runs and a remap?

For a proper custom map about 295 quid mate. Well worth it though. Car behaves entirely different and I gained over 10 bhp, not something the rs tuner will do tbh

 

[steviekyle13793]

I currently have an RS Tuner (98 Ron) map on my car, can they still map it? I've heard rumours about the RS Tuner locking the ECU ...

 

[Dan@SJM]

Yeh it's an awful bit of kit for any future mapping.

 

[Bear Head]

I currently have an RS Tuner (98 Ron) map on my car, can they still map it? I've heard rumours about the RS Tuner locking the ECU ...

I'd give paul a try mate but I'm sure it wouldn't be an issue. Think be used the RS Tuner to link my car up anyway.