just had a recon td05, z4 ecu and walbro 255l fuel pump fitted to my 95 wrx import wagon, didnt have much chance to drive it hard on the way home, it juddered a bit when i first booted it then seemed fine (pulled well and felt faster), drove it today and its struggling to get past the 0.7 bar boost it was doing on the td04 and standard ecu (should be 1.1 bar now i believe).
its spooling up then before peak boost is juddering badly, felt similar to a fuel cut and is no faster than before , its going back to the garage mon morning but would like any help i can get with this please to sort it asap.
should also put it drives fine off boost and low boost this is only happening when giving it some.

 

is the ecu correctly 'mapped' for that turbo? maybe 'mapped' is not the right word as not sure if the early ones are mappable, im not too hot on this subject but surely mod of this calibre need to be set up! sounds abit like your fueling is way out, what was the reason for the change in the first place?

 

the z4 ecu and td05 turbo both come from the wrx 4 door and is quite an easy and popular upgrade for the wagons ive been told on here, i got them fitted for more power.

 

coil packs ?

 

Z4 will only give you 0.9bar, fuel cut is set @1.02bar. To get to 1.1bar you will need at least a Polarperformance chip as the Z4 is not re-mappable.

JGM's suggestion of coilpack(s) will prob be the cause of the problem

 

i thought the z4 went to 1.1 bar, i dont know anything about the coilpacks why would they die from changing the turbo and ecu? are they expensive to replace and is there a definative way i can find out if its them? the car was running perfect before.
thanks
neill.

 

Nah Neill, heres the specs,
Boost Targets & Fuel-Cut Limits

WRX/STi Saloon ECU's 2C, U8, W6, W9 - As above, 11.47psi held to redline. Fuel-cut 14.57psi

WRX (1995/96) ECU Z4 - 12.71psi, dropping to 11.78psi @ 6600rpm. Fuel-cut 15.65psi.

UK/Aus/Euro ECU's V7, 7D and 6D - 11.47psi, dropping to 9.47psi at 6600rpm. With Fuel-cut @ 14.87psi

UK Prodive ECU - 13.33psi (peaks to 13.64 @ 5600rpm, drops to 12.71psi @ 6600rpm). Fuel-Cut 15.65psi.

STi RA (1996) ECU 7K - 13.17psi (peaks to 13.64psi @ 5800rpm). Fuel-Cut 15.96psi.

WRX Wagon ECU V9 - 10.55psi dropping to 6.84psi (starts to drop @ 5000rpm). Fuel-Cut 13.79psi

Coilpacks will brake down at higher power levels, best way to check is to remove each one and look for cracks/damage esspecially behind the rubber on the plug end. They come in at c.£250 a set iirc so not cheap but very nessisary. JGM use to sell them but i can't see them on his web site now, pretty sure apiengines still do.

 

put the car on test mode conecting them green connectors at the bottom of the steering colum behind the cover, and with the ignition on, disconect the pipes connected to the boost solenoid, and clean the pipes with some break cleaners, and put back on, and take of test mode, and KABOOOM you back to normal, common problmes mate.

 

Thats not the problem. If you have dirty boost pipes it normaly overboosts. Think JGM is on the right track. the car has more air and fuel flowing through it now so if its spark isnt 100% it will run like a bag of ****. Coilpacks,plugs or maf is my guess.

 

could be the coilpacks, but before buying new 1nz, give it a shot, clean the boost solenoid pipes, i had the same problem with my sti, wouldnt boost over 0.5 bar, cleaned it, and it was hiting 1.1 as it should. worth a try

 

thanks for all the replies guys, things seemed to have settled down today, i filled her up then booted it as she was under 1/4 of a tank and it spluttered first time then seemed ok, got the wife to watch the boost gage and its hitting the .9 bar ok now, i am wondering if it was down to not having enough fuel and the ecu needing time to settle in?
it was definately hitting 1.1 bar after i first got it back though, i am going to get it on a rolling road asap this week though and see whats what, i shall also get the coil packs and maf checked.
cheers
neill.

 

Good

But unless the ECU is chipped or has a daughter board fitted it can not hit 1.1 bar as that is 15.95psi and the fuel cut on the standard Z4 is 15.65psi. Unless someone has fitted a 'fuel cut defender' which are bad bad bad!!!

Could be your boost gauge is a tad out

Are you using V-power or Tesco 99?

 

i chucked some tesco in yesterday but filled up with v power today.

 

Yeah thats cool

Personally i only use V-Power, the fuel can make a hell of a difference

 

right just got back from rolling road and here are the results
223.9 bhp



and just under 260 lb/ft



happy with the torque, it peaked at 210 with standard turbo and ecu, but a bit let down with the bhp figure, that was 203 with standard bits.

the good news is they say it is running fine and holding boost well but i could do with getting rid of both cats.

 

The z4 ecu and td05 combination do work with a wagon engine BUT there was a rumour on here a few years ago that the compression ratio of the wrx wagon engine is slightly different to the saloon engine. This means that the wagon engine with td05 and z4 will not make as much power as a saloon engine.
When I fitted a z4 ecu, td05, full 3" decat and ported headers to my wagon I only made 260 bhp. I was dissapointed as the z4 ecu should give 256bhp standard, I was running 99ron fuel and the mods described which should have given me more than that IMO. I put it down to the comp ratio.
My 93 wrx with u8 ecu (16 years old) made 245bhp last month which runs less boost than the z4 ecu. Meaning, you should be able to achieve close to the 260bhp mark if the comp theory is not true and your car is not running right.

If the car is still not boosting correct then are you sure the ecu is a genuine z4 ecu?
Have the boost pipes been checked for correct plumbing and is the restritor still in the bottom hose on the solenoid?

Did the dyno run not produce a boost graph?

 

well it says z4 on it and i bought it from someone on here so i would hope its the real thing, the boost seems to be fine now and was holding fine on the rolling road, they told me that someone else had been in recently with the td05 and z4, also he had a decat frontpipe and some sort of chip on the ecu and was only getting 250 bhp, so as you say it looks like the wagons cant fully use this combo, on the plus side i am very happy with an extra 50 lb/ft of torque, just need to save up for the next upgrade - front mount, injectors, decat and remap.