Hi guys,

 

When travelling at low speed say 20mph in 2nd or 3rd gear the car seems quite hesitant really. Seems to have occured since I fitted the boost controller. It feels a bit juddery as though the fuel isn't getting through quite quickly enough if you know what I mean.

 

Above say 2.5-3k revs it's fine and you can't notice it. It also doesn't happen all the time lol. Weird one

 

Any ideas?

 

Chris

Any ideas?

 

It's almost as if a coilpack has gone and is quite a juddery ride below 2.5-3k rpm at around half throttle. Beyond 3k rpm and it's fine and there is no loss in power either so I don't think it's a coilpack...

 

Could it possibly be my ptu on the way out as I've read a few peoples comments about the car being a bit lumpy and running crap just before it went completely.

 

Don't think it will be dodgy petrol? I've only been filling up with v-power.

Vaccum leak in a PVC pipe would do that hesitiant thing (not sure if 300zx's suffer from this?)

 

Dirty air intake also causes hesitancy

This is really weird. I thought it was down to dodgy v-power petrol because I went to a shell garage last night, filled up with more v-power and it ran fine. It's ran fine all of last night and today until I've just this second taken my girlfriend to work and it's starting to do it again.

 

It's really hesitant upto about 2.5-3k revs and then it's fine.

 

What shall I look for?

Another thing I noticed was my apexi avcr boost controller was overboosting for some reason.

 

I set it up to 1.03 bar the other week and i've tested it for days to see if it would over-boost and it didn't.

 

When I was having these low speed juddering issues, if I seemed to put my foot down it seemed to boost loads and the car seemed to be quite laggy. I looked at my AVCR and it read as 1.15bar at about 6k rpm. I looked at the duty to see if somehow someone had changed it but it was all as I left it.

 

Ideas?

Anyone with any other ideas?

 

It's quite strange, last night it was doing the hesitant juddering and it started to do it from when I started her up this morning for approx 1 mile then it was fine after that and has been fine all day. Haven't been out in it tonight so not sure whether it's doing it. Would that indicate it's related to the temperature of the engine possibly?