Dyno dillema Im running rich

Arnie

Worth covering off my mods first:
2.4 mani with with vocky's egr and FPR mod
Piper Cams
Miltek with 200cell sports cat
Courtenay modded intake airbox and panel filter ( on standard intake pipe)

I had a thorney stage 2 map which I thought could be improved by Courtenay and so i went to them for a Dyno and remap, the graphs below show the results before and after the remap which TBH I was a little dissapointed with but they were ok.
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I realised after i had got back from the mapping that i had an untensioned timing chain ( my bad) which i fixed. I thought it was likely that this may have effected my dyno reading so i was keen to get it back onto a rolling road which i did to day at surrey rolling road. The results are not good im down 17bhp and the AFR is way rich:.

Any ideas what has happened notsure.gif

TIA

Clive

n17ves

notsure.gif i think you have to question the accuracy of the rolling road.

I wouldn't expect by having the tensioner not correctly released to loose (or gain in this case) more power because the chain is automatcially tightened between the camshafts/crank when under load/acceleration - you were very lucky that it didn't jump under on de-acceleration though!

Arnie

Me neither - iv'e lost power since i correctly released the tensioner 173 down to 155 notsure.gif

I dont really understand it myself though 10:1 for AFR is way to rich, i thought optimal for NA was around 12.5:1 but i really dont know too much about it, thought that this could point at something going wrong between the two dyno runs and, as above, all i have done is had the cam cover off and released the tensioner. For now I'm going to assume the Dyno's are reading right :? .

edbutler

How does it 'feel' compared to the first time??

See the thread about my RR session recently, my car was really really suffering from heatsoaking (im pretty certain), how were the fans set up on the rolling roads?

Im sure i remember somewhere reading (on here of vx220.org) that someone had a remap on a Z22SE and their fuel trims, modified by the remap basically reset themselves back to standard... Does anyone think this could be true..?

Arnie

All i can say is there wasnt a dramatic change, the car still feels ok to drive if anything the reponse has "smoothed out" i may have a chat with courtenay's tommorow, I cant beleive that two dyno's can read nearly 20 bhp different?

Arnie

Detail i should have mentioned is the tickover has risen from 850 to 950

Karlosfandango

I'll be interested to hear what is said as I'm about to get mine booked in for a remap.

Arnie

I have had a chat with the guy's at Courtenay's. The map should not have effected the tickover so something has definetly gone wrong, summiesing if the ECU is doing it's job correctly then i guess the suggestion is that something is supplying rouge signals to the ECU?

Suggestion from courtenays was a possible cooked EGR cheater, but equally i guess this could be lambda 1, I understand that lamda 1 is responsible for fuelling ? I have no ECU errors

I have an ODB reader is there is anything i can look to indicate what might be wrong?

All suggestions welcome especially on how i can diagnose this

vocky

fuelling is controlled by the mixture lambda, might be worth changing it

out of all the hundreds of egr cheaters these are the reported 'failures', one had a dodgy diode, one had a dodgy connection to the engine loom and the last one was changed and proved not to be at fault, so not as bad as people think dunno..

Arnie

To be honest im not even sure that the EGR cheater can effect the fuelling? is it not more likely it would just fail and error than have an influence on the fuelling

zafman

mine ran rich when i had it in for its MOT.I put a new sports cat on and that fixed it.Might be worth having it checked

Arnie

well i have changed the front lambda and it hasnt made any difference 🙁 has anyone got a .csv file showing the odbi readings for the pre cat and post cat 02 sensors with time and rpm so that i can compare my readings against, other than a tickover at 1000rpm there is nothing to indicate a problem so I'm keen to compare the post cat readings. My pre cat 02 sensor seems to be ocillateing correctly between 0.2 and 0.8

vocky

I think Luna_s might have those, he did some research when he had a duff lambda

Arnie

Thanks i looked -luna_s has an 02 sim so they arn't real readings. Vocky would you know if high tickover could be a result of rich running or am i barking up the wrong tree, it doesn't appear that when luna had the problem he had a high tickover

vocky

high tickover can be an air leak, might be worth sealing the tb to the manifold

Arnie

thanks i'll give that a go next