Boost or loss of power between 4000 to 5000
 

Having problems with boost bewteen 4000 to 5000 rpm in all gears. When I put the foot down upto 4000rpm car pulls hard, but when I hit above 4000 to 5000 the revs still climb, boost is still climbing on the boost gauge but car doesnt pull.

Ive replaced the maf {done the maf test unplug it when idle and it cuts out}, cleaned out the boost solenoid, put 4 brand new coil packs on, had a check around the hoses nothing stands out. Done an ecu reset.

Ive bought new spark plugs and a lamba sensor both still to be fitted.
What else can I do here any comments please to help me sick scooby out.


Can someone confirm ive got the correct lamba sensor with pics ive supplied.
Also stamped on the part is:

LSH23
0258003995
4880321
12V
982

http://i7.photobucket.com/albums/y26...0015Medium.jpg
http://i7.photobucket.com/albums/y26...0013Medium.jpg

:wonder:

Are you using a non std ECU or an AFR trim adjuster like an HKS?


Nick

Ive removed the boost control, plumed the hoses back to standard, but yes im using a non standard ecu. Ive had this car for about 4 months, this problem has started about a month ago. So dont think it could be the ecu

ifr it is a early classic check the coil packs for cracks

Did the problmes start when the boost control was removed?

4 BRAND NEW FITTED

No problem was there when boost control fitted

'When I put the foot down upto 4000rpm car pulls hard, but when I hit above 4000 to 5000 the revs still climb, boost is still climbing on the boost gauge but car doesnt pull.'


sounds like the clutch is slipping to me rather than a sensor issue? or have i missed something here?

clutch slip to me too.

Sounds like the above, clutch

I really hope not, too much £££

yeah mate doesn't sound like a sensor issue at all, if it was and the ecu was backing off then you'd drop revs, boost would drop and you'd slow down. If its clutch you'll still get the revs and boost but you go no where. I def think its your clutch so i wouldn't spend any more time chasing ghosts and get that looked at.

**UPDATE**

Took the car for a spin. If I drive the car sensible through the gears it pulls all the way up the revs with no probs. If I floor it through the gears, when I hit 4000rpm the boost stays at 0.5 bar, then when the revs hit 5000rpm the boost climbs upto 0.9 bar.

Spoke to my mate whos a mechanic, he reckons its either the spark plugs or the lamba sensor. As the car was fitted with colder spark plugs { NGK PFR7B } 5 weeks ago in its service. He thinks the plugs could be the root of the problems. Anyway the car is booked in on Tuesday to sort it out


So far Ive been told it could either be:

the clutch slipping
failing maf
failing coil packs
failing cat
split hose
faulty spark plugs

I will post my out come to the root of the problem when its comes back from the garage, so it may help someone out in the future

ahh that changes things.

what year car and model is it?

96 pre-face

sounds like for some reason its holding back boost

Its the plugs mate had similar prob with mine replaced maf coil packs lambda sensor and then plugs was only when I changed the plugs it cured

Personally I think its the plugs as well. May as well do the lamba conversion, since ive got a new one here.

{move the lamba to the downpipe & disconnect the one in the manifold}

The coils packs I removed are in excellent condition, sale any one ?