Since putting in the boost jets (1.2mm) i have noticed the gauge reading is different. What I mean is, before when throttle was even, ie;not accelerating or slowing, the gauge read zero, now it reads minus 4 or 5 in the same conditions. can anyone enlighten me as to why the change in the reading ? does this mean the boost reading is now wrong ? Where does it take the reading from ? any help ? just concerned I am doing the right thing Cheers :thumbsup:
The boost gauge is actually electric, I'm assuming that it's a >>>> voltmeter. the boost pressure is supplied to a convertor (for want of a better term) via an 1/8" pvc tube, the convertor converts this pressure into an electrical signal and supplied the boost gauge. When my Boost gauge started playing up I found that the tube feeding the convertor had a split in it about 10mm long. This of course caused the gauge to read low, so this may be your problem too. if not then you may have knocked of another hose somewhere when you fitted the jets. The convertor is mounted in the engine bay, drivers side right up against the fender wall towards the firewall, it looks a little like a relay except it has a small hose going to the underside. Check all the hose connections and examine the small hoses (there's 2 or 3 in the vicinity which are all associated)for any splits or breaks.
Boost Gauge Expectations The Standard boost gauge is not super accurate but is a guide. I have a feeling that you may have inadvertently fixed a vacuum leak. An engine in good condition with no vac. leaks should have high vacuum at idle and steady throttle. On acceleration the vacuum needle should move towards zero then into positive pressure as the turbos do their thing. I hope this helps
2nd - mine reads negative 4 or 5 at idle That's where it's supposed to be. Doesn't approach 0 until you accelerate and then goes positive at about 3000rpm as the turbos kick in. Cliff
Your memory must be playing tricks on you...>> The only time it should read 0 constantly is with the ignition on and the engine not running. At idle, it shoulds always be negative.
