XRTypeRS

I had my boost / fuelling adjusted last week and Ive noticed that I get a lot more popping and banging on overrun now than I did before. What could have caused this?, I believe the fuelling has been increased to match increased boost would this have an effect on overrun?.

I also "think" im hearing a slight bit of "pinking" too and the tuner has turned the dizzy slightly clockwise when viewed from the cap end. Does this need knocking back a tiny bit? (I cant think it would be det as I believe its running richer now)

Cheers,

Stu

Ragtop

The poppin could be induced by a small hole further up the system, letting cold air in.. I'm sure my Magnex is leaking a tiny bit up front, and that's probably what's making mine so good.. The more poping and banging the better I say..

Is it at a particular rev range, or all the way thru..???


Luv
Chrisie...

rs_si

Its the extra fuel thats making it pop and bang on overrun.

XRTypeRS

Chrissy, I dont think its an exhaust hole as its just happened since it was adjusted, it popped a bit before but they are proper bangs now!. Its most of the rev range when the throttle is shut.

Im glad its extra fuel as least (hopefully) that means that the pinking is not due to it being lean. Its DRINKING fuel now....

So what about the pinking?, too much ign advance?. Im going to buy a timing light tonight and see what its set to..

CabrioTurbo

And probably filling the sump with fuel as its doing so
There are a number of things to look at... is the car running Mfi, Efi or webber?
It does sound like its overfueling TBH

KSA-Cossie

iTrader: (4)

does your throttle switch click? if not it needs adjusted mine did that before.

Jim Galbally

there should be an overrun fuel cut on an ERST so yours sounds like its not workin...

also if you suspect it MIGHT be pinking, GET IT CHECKED... tuners make mistakes too...

AlexF

Its over fueling off throttle


alex

XRTypeRS

Its MFI but it was setup on the Rolling Road so it should be pretty near what it should be. He said he set it a bit rich to try and help cool my zetec pistons that are in my engine.

Jim, I have an Ahmed chip and I believe that fuels on overrun as standard to cool the piston crowns. I would normally agree with your "get it checked" statement but I did the right thing and got it setup by a pro and this is the result.. Im not going to risk spending another wad of cash and it still not be right - I get the impression that I will get charged again if I take it back...

Wish Id left it alone now, it was happy at standard boost and has not missed a beat for 20K - it'll teach me for being greedy

AlexF

If your not happy go get a better chip/setup.

Overfueling on over run does indeed cool the pistons... but it wastes fuel!

Alex

XRTypeRS

True alex, but Im afraid Im loathed to chuck more money away now - Im afraid I have not been that impressed with any of the tuners Ive visited so far and Ive got no faith that it I go to another one they will be any better. I just want to back it off a bit and get it running OK again, not to bothered about loosing a bit of power, wasting a bit of fuel, reliabilty is more important.

CabrioTurbo

The 'chip' in the RST has nothing to do with fueling.. it is only ignition curve.
Im not a master mapper but i dont see how it can be 'set to overfuel' on overrun...
The only way to adjust the Ke-fueling is via the meetering head and i only know a coupple of people who are able to do this.

There is no point going to any old tuner You need to choose the right one... someone who knows about modified fords ZVH/CVH/Zetech difference etc.
My recomendation would be Karl Norros although he is prob Very busy at the moment.. otherwise why not try Stu @ MSD ive not heard a bad word about his work yet
CheeRS
Phil

Ragtop

Personally i'd change Phils preference's round the other way.. I know who i'd go see first.. but he's still right..


Luv
Chrisie...

Stu @ M Developments

iTrader: (12)

Go out to your car and move the throttle linkage by hand.
It "SHOULD" click positively from the switch. If it doesnt then thats your problem, in this case call me on the number below and il tell ya how to adjust it "FOR NOW" until such time as you have her checked over......

EscortWRC

Sounds like 'lean pops' to me....

XRTypeRS

Sorry for the delay Ive been outside and done the following :-

1). Adjusted cam timing back to where it was before setup (i.e. its now slightly retarded compared to where it was - turned dizzy anticlock just under 1mm - there was a punch mark for the previous setting).

2). Removed the bleed valve that was added am now back to standard boost.

Checked TPS, is clicking OK, tested with meter, seems to be switching OK too. I dont think there is a problem with this as there is a noticable "lurch" when the throttle totally shuts (as there always has been).

Been out for a test run and it "seems" to be popping slightly less, also seems OK when on boost (upto 8psi with amal switched off). Still having the odd backfire when amal valve is back in and boost peaks at 11psi. Checked coil, primary 1.2 ohms, secondary 7.6K ohms (slightly high coampared to Haynes?). Volt drop to from battery to coil +ve 0.2v at idle, nearlt 0.5v at high revs. Probably going to order a grp A from Mike R to see if this can solve the misfire.

As for pinking, this "noise" seems to be when you floor it at low revs off boost. It does sound like pinking (using my mums Renault which contantly pinks as a reference!!) but it could just be the exhaust creaking and me suffering from RS paranoia. Could it pink "off boost" at low (2-3K) revs?. As mentioned previously it should be fuelling more than it use to as it was turned up so I cant understand why it would be pinking and "lean popping" now its back to how it was pre setup apart from the EMFPR settings??.

Any ideas anyone? (cheers for the offer Stu bu the way )

Cheers,

Stu

Jim Galbally

yes it can pink off boost...

full load n low revs is where it likely to do it anyway iirc

i love the way you pay loadsa money for a tune up then put it all back how it was beforehand

mate, take it somewhere reputable, as by the sound of things you used you local backstreet pikey garage to do it...

...am i right?

Mark V8

iTrader: (2)

Popping on the over run is down to a lean mixture AFAIK, the unburnt exhust gases don't burn in the exhaust itself and build up resulting in a loud POP! when they finally ignite I've leaned off the low end fuelling on my turbo bike by a fair bit and it now sounds like WW111 going on behind me when I throttle off. Kind of pisses you off after a while and will do no good to your exhaust internals.

Mark

XRTypeRS

Jim, thats the whole point , it was somewhere reputable, they have a good rep on here , hense why I was willing to pay what I consider high prices for the setup. I wont be going back...

Mark, as it only pops when the throttle is shut on overrun will this be the idle fuelling thats wrong, i.e. the allen key on the KE unit as opposed to the on boost fuelling which is set by EMFPR adjustment?

vroooom ptssssh

Jim - only 16i's have the fuel cut off on over run.

u said u "think" its pinking.......it may not be!

popping and banging is due to it overfueling slightly on overrun, unburnt fuel going into the exhaust and igniting when the exhaust temps get up, take it for a blatt up the mottorway, sit at 100 for a we bit then floor it, lift off and let the revs roll down themself and it should do it (sounds good i think)

Unless u find out it IS pinking i wuldnt worry.

XRTypeRS

Dave, your right that it doesnt do it on initial start up, only when the exhaust has started to get warm. Your probably right with the "pinking" too, its always just a "click click" when i floor it at low revs, I know my mongoose creaks when I reverse (great design that they are with no flexi section ) so its probably just that. I will be running some more tests 2nite to try and listen some more.

My concern at the moment is that when I took her out last night after a big bang I got at 5K when (I assume) the spark blew out again it was then missing once or twice off boost at light throttle - could the misfire have upset the plugs or something?.

What does everyone think of the GRP A coil idea?, would this be a good move?

Cheers

Stu

XRTypeRS

BTTT

vroooom ptssssh

think a GRPA coil wuld be wasted money imo, theirs no need for it really, what plugs do u use? are they gapped correctly? im not sure what plugs u need for different specs but mine r NGK BC8 RES and have no probs, jus std tho
anyway, i dont think the loud "pop/bang" would of done any damage to a plug as the explosion of unburnt fuel wuld of happend in the exhaust. if its miss firing now then check dizzy cap/rotor arm/plugs/leads, also could it be missfiring as a result of you changing the ignition timming?

get it to a well known rr who know their stuff and explain all your symptoms/problems/thoughts, tbh their ws prob no worries with it after it got set up, u maybe jus parranoid as u said b4

dont worry bout the poppin an bangin at all btw........

XRTypeRS

Hi Dave,

Yes well known RR that set it up changed and gapped plugs, fitted new dizzy cap, rotor arm and leads as spark was blowing out at 10 psi. This improved matters but obviosly spark is still blowing out once in a while (I assume) causing the big bang. Checked out electrics as said above and they seem resonable, hense why I am thinking about the coil.

Cheers for trying to put my mind at rest about the overrun noises !!

vroooom ptssssh

no worries, maybe try a new gap setting on the plug cos if the spark is still blowing out only thing i can think of is the gaps too big u got std plug leads? if not get a set! hope u sort it out let me know ho wu get on.