14 replies to this topic

[Twisted John]

Recently bought a VXTurbo from a chap who uses this forum. Its a stage 4 , charge cooler, vxr turbo etc etc. It has a air flow problem just developed - it used the VXR 80mm airflow meter, got a new one today, didnt sort the problem like I hoped it might! Could it be pulling too much air via a bad duct from the air box? I noticed it still had the standard filter and air box. Do I need to ensure the duct from the air box to mass air flow is silicone and not cheap ducting? Are there any other common faults / sensors to check? It drives with the air flow disconnected , just majorly down on power. Engine warning light is on. With new air flow meter in place it chuggs and coughs like hell.. Ideas please?

Edited by Twisted John, 28 February 2011 - 09:04 PM.

[VXT Tim]

Possible the inlet track from amm to turbo is colapsing. Few have had this problem. Does is rev then suddenly drop power under load. Could be a number of things to be fair.

Edited by VXT Tim, 28 February 2011 - 09:28 PM.

[Twisted John]

Possible the inlet track from amm to turbo is colapsing.
Few have had this problem.

Does is rev then suddenly drop power under load.

Could be a number of things to be fair.

Thanks for reply - On the old air flow meter it would pull Ok to 3000 then chokes. It has silicone and 3 inch alloy tube from the airflow to the turbo. I might have to see if the silicone is colapsing - But I guess this doesnt explain why it drives Ok with air flow unplugged.

with it plugged in it will rev if I make it but die and idle lumpy!

Bummer!

[VXT Tim]

Possible the inlet track from amm to turbo is colapsing.
Few have had this problem.

Does is rev then suddenly drop power under load.

Could be a number of things to be fair.

Thanks for reply - On the old air flow meter it would pull Ok to 3000 then chokes. It has silicone and 3 inch alloy tube from the airflow to the turbo. I might have to see if the silicone is colapsing - But I guess this doesnt explain why it drives Ok with air flow unplugged.

with it plugged in it will rev if I make it but die and idle lumpy!

Bummer!

It's not a collapsing tube then as the silicone from airbox to amm is too short to collapse and you have an alloy inlet pipe.

Few things to check are plugs, possible/probable coil pack gone, split pipe.

ETA there are 2 boost solenoids I think, I also think one is more prone to failing, sure someone more knowledgable will post who will be of more help .

Edited by VXT Tim, 28 February 2011 - 09:52 PM.

[VXT Tim]

Some potential helpful info in first post on this thread http://www.vx220.org...-issues-solved/

[Whiteboy]

When he fitted the 80mm afm, I take it the map was altered? Has it ever run right with this set up? Steve

[siztenboots]

coil pack

[Nev]

Rev hunting at low rpm (especially when idling) is often attributable to leaks in the air track (either before or post turbo).

[Joe-Turbo]

Possible the inlet track from amm to turbo is colapsing.
Few have had this problem.

Does is rev then suddenly drop power under load.

Could be a number of things to be fair.

Thanks for reply - On the old air flow meter it would pull Ok to 3000 then chokes. It has silicone and 3 inch alloy tube from the airflow to the turbo. I might have to see if the silicone is colapsing - But I guess this doesnt explain why it drives Ok with air flow unplugged.

with it plugged in it will rev if I make it but die and idle lumpy!

Bummer!

It's not a collapsing tube then as the silicone from airbox to amm is too short to collapse and you have an alloy inlet pipe.

Few things to check are plugs, possible/probable coil pack gone, split pipe.

ETA there are 2 boost solenoids I think, I also think one is more prone to failing, sure someone more knowledgable will post who will be of more help .

Im pretty sure the solinoids prone to failing are on the standard turbo. The vxr turbo has new solinoid fitted

[SteveA]

Mine did this a few years ago. The wiring to the MAF was at fault. Try some continuity testing before you spend any money. Could just be a 5 min soldering job.

[Twisted John]

Still trying to figure this one out - Havent had time to investiage as I have been busy with work; Drives good and with no issues with airflow unplugged - Just not running the full 100% power. more like 75% power. diagnostics is giving a fault code relating to high air flow reading. It runs on a VXR airflow meter - Just replaced it with a new one still not running right. chases revs at idle with airflow plugged in - unplugged its fine. Any ideas please?

[VXR 43]

As mentioned before, has the VXR Maf been setup on the map accordingly?

[Twisted John]

It has - Only had the car 4 weeks - Ran superb with mega power until the fault appeared - On the VXR 80mm airflow meter. I put that to fault but as it turns out its not the fault.

As mentioned before, has the VXR Maf been setup on the map accordingly?

[turbobob]

sticking butterfly in the throttle body?

[Twisted John]

sticking butterfly in the throttle body?

Doesnt explain how it will drive perfect with the airflow meter unplugged? Just down on power with it unplugged.

Thanks