XU10j2 with a 1.9 Gti cam

[calvinhorse 870]

I’ve fitted the 1.9 Gti cam to a XU10j2 (405/306 2.0 8 valve) the ecu is the standard 405 one 

 

im happy that the valve clearances are perfect, spark plugs are brand new, new petrol filter and I even had the injectors reconditioned.

 

im getting a slight misfire/stutter at 1500 - 2000, it’s not noticeable while driving and actually sounds pretty good when you just rev it

 

queation is, is this just to do with the map being completely wrong for this cam or is something else at fault? This used to be quite a popular mod back in the day so anyone with experience that could shed a little light, thank you 

[welshpug 1,661]

I doubt the map will be that far out as its only 6 bhp, did you stick with the standard black injectors?

 

 

which vehicle is it in?   I have had a symptom like this when a VSS is not working, which I think that ecu does use.

[jackherer 543]

42 minutes ago, welshpug said:

I have had a symptom like this when a VSS is not working, which I think that ecu does use.

 That was my first thought when I read this thread but I think the symptoms are the wrong way round, the lack of VSS stumble is normally noticeable when driving (pulling away in first mainly) but not when you rev it in neutral.

 

3 hours ago, calvinhorse said:

im getting a slight misfire/stutter at 1500 - 2000, it’s not noticeable while driving

 

[calvinhorse 870]

Yes standard black injectors, I’m pretty sure I’ve got a spare vss I can try, it pulls away fine they usually kangaroo when the vss has gone don’t they?

 

its in a 405 which was an auto but the ecus are identical so I think I can rule that out

[jackherer 543]

11 minutes ago, calvinhorse said:

it pulls away fine they usually kangaroo when the vss has gone don’t they?

Yes, it makes your passengers think you can't use a clutch properly...

 

That is about the right RPM range where an automatic ECU would potentially have different mapping to account for a torque converter flaring up but again I think if that was the issue you'd only get the stumble while driving, revving it in neutral would be basically the same with an auto or manual box attached.

 

Edit: sorry, I misread that, the car used to be an auto, not the replacement engine. Pretty sure that wont make any difference.

Edited February 25, 2020 by jackherer

[DamirGTI 342]

5 hours ago, calvinhorse said:

spark plugs are brand new, new petrol filter and I even had the injectors reconditioned. 

 

Did these at the same time as the cam replacement ?

 

From memory , these two cams are near identical in terms of lift , just the overlap difference (more overlap on 1.9 GTi cam , less on 2.0 j2)

 

D

[petert 588]

I agree. I posted the full specs on here not long ago. Hardly worth the effort of changing it really. Something to keep you busy though!

 

edit: It was longer ago than I thought!

https://www.205gtidrivers.com/forums/topic/172191-20-8v-t/?tab=comments#comment-1517021

Edited February 25, 2020 by petert

[DamirGTI 342]

... seems that time does fly faster as we get older !

 

 

D

[calvinhorse 870]

It may not look a lot on paper but it has really livened the engine up, it felt lazy before, you’d change gear at 5k because it didn’t do anything, don’t get me wrong it’s still slow as sh1t but it cost me nothing other than time

 

i didnt have a vss so drove it with it unplugged and it’s undrivable so maybe that is working