ScottyDog

Hi,

This could turn out to be a long winded post so bare with me as if I give you guys as much information as posibble hopefully we can pin point the problem as it is spoiling the enjoyment of the car.

I have a MY00 wagon. Now when accelerating through 3rd, 4th and 5th gear the power appears to come in waves. Accelerates hard then dies off, then accelerates hard and dies off etc until grabbing another gear.

Initially I though it was a fueling issue as the previous owner used normal unleaded and I had been using super unleaded since I got it. So I though it would just take time for the ECU to reset. So I didn't drive it hard in the meantime, keeping off boost as much as possible. However 200 miles latter the problem is still there.

So I reset the ECU manually as per a few threads on here. The check engine light flashed continually at half second intervalls indicating successful reset and no fault codes. However again the problem is still there.

So before I try anything else I am opening it up to you guys. My thoughts at this point in time are:

1) Could it be the MAF, but bearing in mind no fault codes? Prehaps it just needs a clean, but I have read that cleaning them can do more harm than good. Could just replace the sensor, but don't want to go through the expense for it not to be that.

2) Could it be the spark plugs? Worth taking them out and cleaning? If so does anyone have a quick guide / tips to getting them out before I start?

3) Could it be the boost solonoid (spelling???). It appears to be a recent unit on my car if it is the same thing I am thinking about. If so does anyone have a chapter and verse on cleaning them (pictures would be appreciated)?

4) Could it be the dump valve? On my car it is an aftermarket unit - Forge. How do I check it is set up as should be.

Anything else?

I have though about taking it on a rolling road as there is one near to me. How effective are they at identifying these types of problems? Or does it depend on the knowledge of the operator?

Nearly forgot to mention the car is standard apart from a Magnex backbox, a BMC panel filter and the forge dumpvalve (all done by previous owner).

Thanks in advance for the reply's.

Scott

Tomski_908

iTrader: (1)

Check boost pipes, i had a silimar problem and it turned out to be a split in the hose that runs under the intercooler!

mcvicar

Agreed,
I had exactly the same problem, cleaned the boost valve with carb cleaner while ecu reset wires connected. The amount of crap that came out was unreal. runs without fault now.
Hope this helps

tim.gilbert23

iTrader: (3)

i have same problem.. any advice on cleaning the boost valve..and indeed whree it is ?

best_quality03

on the pre 96 saloon the boost sonenoid is bolted to the suspension turret off side behind the air box just remove the 2 or 3 pipes depending if it is 2 or 3 port solenoid, disconnect the wire, remove from turrret (2no 10mm nuts) and spray brake cleaner/carb cleaner into the pipes that the rubber hoses fit onto if its dirty the cleaner will come out black if its clear then its clean. Did mine today but it was spotless (going for rolling road in the morning so wanted to make sure everything is spot-on) Its an easy job just make sure you note which pipe goes to which port. this is VERY important DONT GET THEM MIXED UP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

tim.gilbert23

iTrader: (3)

mine is 99.. will it be same ?

Tomski_908

iTrader: (1)

Yep

ScottyDog

Hi,

Thanks for the reply's so far. Is the location of the boost solenoid for a MY00 car in the same place as described by best_quality03 above as I thought it was on the near side turret on my car?

Any picture anyone help clear things up?