Well...Im reaching out. Im not sure where else I can turn to, except the blokes that know these things inside out
So a couple of weeks ago, I contacted a reputable person who creates mail order tunes...
I asked him if he was able to perform a tune on my new engine... (A 5l in a GQ Patrol) Please note it was running a VP memcal at this stage.
The specs I gave him were..
Crow Cam 4631
280 150 973 injectors (Series 1 VT Injectors ive been told)
Flat top pistons (40 thou over I think)
Ported and flowed heads (Bench tested)
Roll master timing cog and chain (Ive been told this has been set to stock)
Flat top hypertec pistons
70mm throttle body
Upgraded coil (Nothing fancy, just something better than stock coil)
Upgraded Ignition module (Is the stock item with an extra transistor)
Im running a loom from Marks 4wd Adapters with a speed sensor box from them too (Part no MFK696 (http://www.marks4wd.com/products/engine ... n%20V8.htm)
Was really hoping to gain a more stable idle, less surging at low revs, plus if possible the "lean burn" facility to save some fuel ….. and of course a better matched tune to the new motor.
So after a couple of weeks the Memcal turns up, I install it and straight away notice that its idling quite high (950rpm) ....I performed the standard 'idle reset' by revving it for 30 seconds etc....but it doesn't change a thing. I figured I must be doing something wrong and proceeded to use the car for the weekend.
On the Monday afternoon, I gave it a good effort to try and get the idle down to normal levels.
I removed the TB, removed the IAC (Its a brand new IAC) and checked it...everything looked ok, I had cleaned the TB only a couple of weeks before so everything was still very clean...I read somewhere that you can reset things a bit by pushing the IAC stem down, which I did. Reinstalled TB, started the car...but zero difference....car starts, goes to 1200rpm for a few seconds...and eventually settles on about 950rpm. The only thing I can do to lower revs is to block the iac hole in the TB with my finger.
I tried swapping the chip back to my original…this immediately took the idle back to normal…it was a pretty wobbly, but I hadn’t rev’d the car for its 30 seconds etc…
I tried a VN V8 tune for 98 octane fuel…this did exactly the same as my orig chip. Idled as above.
In desperation I tried a VR V8 Auto tune (With VATS removed)…this idled at 1200rpm…and refused to go any lower… (Im assuming it’s a bit higher because its supposed to be dragging a torque convertor ??…)
My only conclusion is that prehaps the VR/VS style tune has something different in it that is making the engine rev too high. I have reported all this back to the bloke that created the tune for me, but as yet, havent heard anything....
I have ordered a ecu with the 8192 baud upgrade from vl500, so hoping very soon I will be able to provide logs of the engine if needed.
Any advice would be GREATLY appreciated!
Thanks
Glen
