Giday, My fully imported 91 Twin turboed Zed (modified in Japan prior to importing) has suddenly developed a massive flatspot. At full throttle the engine simply dies ( as if you've lifted ya foot) around the 4500rpm mark. If you lift ya foot back to around the 3/4 mark the engine gets stuck straight back into it and powers on...... On a couple of occasions there has been a quiet backfire during this 'flatspot', and yes whan I say quiet it can 'just' be heard !! The engine is still reving out but only if you stay away from the full throttle position, this however has meant a slight loss in the acceleration/power the car had a few weeks back....... I've changed nothing, fiddled with nothing, in fact havent even had the bonnet open prior to the sudden apperance of this problem. Can anyone point me in the right direction to find a cure ?
if its a flat spot its probably electrical. so the revs dont stay up there? its not your clutch slipping ? i would start by checking for ecu error codes
interesting, how might O2's cause this? possibly TPS (throttle position sensor)? if near ringwood, you can swing by and we'll hook up consult and check sensor values. pm me.
Had something a bit different Revs don't drop out when booting it, except when car first starts. But on the right hand side exhaust blows a little black stuff out, I'm assuming unburnt fuel, and when I do boot it it sounds like a slight backfire/ bang sometimes, would this mean a faulty o2 sensor on one side?
Possibly.... you need to do more diagnostics, there's a whole list of items you can go through but start with the obvious... Clean all connectors: i.e. corroded CTS may cause backfire as ECU thinks engine cold and runs too rich.
Sweet I'll try to get the data scan program working tomorrow so I can get some more definite info. Cheers
The general consensis is electrical........... looks as if I have a busy day the clutch wont ever slip in this Zed ............. its an auto
Throttle Position Sensor ( TPS ) ... the connector wasnt fully contacting even tho its one of the stupid circlip connectors. This did fix it altho its doing the same thing yet again..... I think it may be time to 'fix' the damn connector once and for all. Whilst its 'looks' connected its actually drooped down slightly and when I push it back it sits correctly, however a bump in the raod means its droops again and the same issue returns. Kingy
Unfortunately I dont live anywhere near a Zed specialist so access to puter diagnostic system isnt an option unless I can take the laptop over to the shed, sit it near the radio ariel and start the car and the lappy will do magical things ..... I'm up that creek with my favourite paddle .................. yet again !!!! Next question tho ....... where does one aquire the program and or connection leads from ???? Kingy
thanks for the info here is Caz1web site she sells them http://www.cazracing.com.au/catalog/index.php?cPath=25&osCsid=4202b3d59544fafb10567cb0cd643600
So I spent a very long day yesterday checking and in some cases re checking all the electrical connectors in the engine bay. The Throttle Position Sensor was replaced which made zero differance The Air flow meter was replaced, again no improvement. ECU swaped ..... zero diff So my thoughts turned to the more 'exotic'...... turbos..... posiably the wastegates arent working thus creating an overboost situation where the puter detects a fault and cuts fuel.... ( yes I'm running high boost so there is the posibility that they are carboned up due to the fact that they rarely open ) end result ...... wastegates are fine mutter mutter mutter mutter Ok ..... fuel pressure is next & Its better than perfect ...... mutter mutter mutter The engine is now responding to full throttle but is hesitating from the 4500rpm mark upwards. Its pulling like a freight train down low in the rev range and running sweet as, its once that 4500rpm mark is passed it goes all pear shaped. The engine will still rev through to 7000rpm but its not a strong or smooth power flow, @ a guess I'm dropping 100kw of power somewhere once that 4500 mark is passed. So Today I'm gunna pull the coil paks, replace em and while I'm there a new set of plugs too. I'm hoping like hell its a simple plug failure ( breaking down under load ), I cant recall the last time they were replaced ..... perhaps 40,000Ks ago at a guess, so they are probably well overdue for a replacement anyway. From what the engine is doing, this idea may be the key, one can only hope. My next thoughts are injectors...... I've had dramas before with em and they have been replaced but the issue was more low rpm than high rpm, there was a bad miss @ idle and dirty fuel was the culprit. All this cost me a club run yesterday....... Why is it things break down just when ya need em to be right. Kingy
is it black and white difference at exactly 4500 rpm? if so, i'd expect some electric type issue. if past 4500, things start intermittently going pear shaped, well it could be anything. possibly fouled plugs?
Did you just steal my zed? mine has exactly the same problems as yours and I have done the following with no improvements: brand new coilpack connectors, brand new injector connectors, brand new splitfire coilpacks, brand new 0.8mm gap spark plugs, boost leak test came out ok, TPS ok, AFM ok, cleaned CAS. Im all out of ideas and all the mechanics I've gone too say that its either coilpacks or AFM. Once i tell them I have new coilpacks and that the AFM is fine they just have no more ideas.
My standard slick top TT is in the same boat too :/ new AFM too :/ keen to find a resolution to this one.
Unfortunately I didnt get to the car yesterday ( visitors should make appointment times ) I did however drive it last night, If the throttle is driven directly to the mat then the powerloss is very noticable, huge flat spots with a faint backfire posiably sounding noise If the throttle is eased on its happy to pull away but there is a very slight hesitation from around the 4500 mark, it wants to go but just wont. I'll try n get to the shed tonite.......... maybe Kingy
