Hey guys,
The other day my VL started idling at around 100 rpm after a minute but doesnt turn off. Then if i take off its fine and driving is fine except when i hit boost its quite laggy till full boost as in not very responsive. You can hear the load its under but doesnt pull like normal. Before it was quite responsive. I gave it a bit by coming on full boost and the car actually turned off :S Any ideas.
cheers
running very rich will mostly make that happen too and that points to AFM,
loom connectors, loom or even same for CTS...
Did you maybe over-rev it to put timing out ?
i cleaned the afm plug and its still the same. i did a diagnostic check and number 34 comes up which is detonation sensor circuit. sounds like its retarding my timing and thats why its laggy. Any ideas what could be causing the detonation?
detonation sensors are just microphones, error 34 doesnt indicate timing is
*always* retarded by 5 deg and that amount wont make it much more laggy,
you can circumvent the detonation sensor circuit but then its up to you to
make sure you dont do something to cause serious detonation.
I've been running my VLT on 10psi for years and had the detonation circuit
bypassed for almost 10 years too
Detonation bypass modification to Turbo ECU to stop error code 34
-----------------------------------------------------------------
In reference to pictures:- "ECU_Detonation..." and "ECU_lights..."
Resistor is 1/4w carbon or metal film value 470K Ohms and
connects to the 8th pin from the right hand side.
ie. White wire to switch on 1st pin, resistor on 8th pin, cant
recall what precise ECU connector numbers these are but refer to photo.
Note: All the bypass toggle switch does is connect the resistor
to the detonation input of the ECU, it relies on the sensor
having been removed from the engine loom. I could have done it
as a proper bypass but didnt want to cut into the connector.
Its fine for me as it is for country economy, I'll be looking at
a better method of providing retard on boost to get back that
little extra power even before pinging occurs.
Do you still have low idle, if so then if its not AFM and/or the connectors
then if its a sudden change from before then there is a high chance you have
an air leak, unscrew cap from cam cover and if there is no change then you
have confirmed it has an air leak.
Some original photos have not been recovered yet.
hmm if its not making my car laggy then i prob wont bypass it. Yeah my car still has low idle, sometimes it nearly idles on 0 but doesnt turn off. ill have a look for an air leak. What do you think could be causing the detonation sensor to go off Mike?
that sensor has been around over 20 years, the cable/connector is subject
to corrosion and in any case the engine probably has more noise then it
ever did when it was from new to 5 years old... Other possible is the sensor
is not in tight, many possibles... I've had mine out for years, no detonation,
run ULP and get great economy in country 9.58L/100kms to Esperance with
auto and otherwise mostly standard computer.
thought i would revive my old thread. when my vl comes on boost there are a few slight misses as im boosting and the tacho jumps a few thousand rpm. any ideas? cheers
sounds like the connections around power transistor, coil, cas etc. Could
be a failing power transistor, car on boost and revs needs good ignition,
might also be getting a bit lean. But if tacho jumping then good chance its
connections or transistor etc... ie. Engine vibrations at load and revs change
dynamics of vibrational state - its more than possible a connection could
not be making 100% under thos conditions but it does when off load, odd I
know but seen stranger things happen... By now also the cables for the
coil power and crimps are subject to corrosion, prob time for a rewire.
But, on reflection the coil is prob easiest thing to swap out first as quick test,
as a failing coil is known to sometimes leak spark back to primary and that will affect tacho
Quote:
Originally Posted by Stooge
thought i would revive my old thread. when my vl comes on boost there are a few slight misses as im boosting and the tacho jumps a few thousand rpm. any ideas? cheers
man i reckon its leaning out and thats probably why there is a trouble code for the knock sensor.
Does the miss occur when its under heavy load like hill climbing? Not sure but have a suspicion that the ecu is retarding timing/limiting boost in these conditions as a means of protecting the motor.
Also has this only started happening since the weather has warmed up?
maybe try running nuthing but 98 RON
cheers Niche and SLY PSI. At night its ok so maybe the hot weather isnt helping. Ill try running 98 and see it that helps and also try another coil. If its running lean i spose i will have to bring it to a tuner and get afr's right
yeh sounds bout right man, very likely that the weather has had somethin to do with it. see how u go with that premium juice and maybe just make sure that its not something easily fixed before u go spend the big bucks with a tuner
good luck
Some original photos have not been recovered yet.
You could have two different faults or rather one fault and one condition.
ie. Engine could be leaning out - reasonably common with older pumps but
you might also have a loose connection on the printed circuit board edge
connector on the top of the dash cluster. If you wiggle this it can make the
tacho go off or sometimes make it jump - this is a poor design and if you havent
had the dash cover off its worthy of an inspection.
It still might be coil and/or power transistor and/or connections, these days
all sorts of things can be a coincident problem
Pin down one thing at a time from the best advice
Some original photos have not been recovered yet.
i havent found another coil to test it yet but i will soon. I tried cleaning dizzy and AFM connections and running ultimate but still the same. I noticed while driving that in 2nd and 3rd gear i only get 1 psi and in 4th 3 psi. its running stock boost so i should be getting 6. Also it only goes up to about 10 vacuum even on boost, then when on full boost it will go to 1 psi. Does that point to a particular problem? Does the ECU limit boost when theres a problem? Cheers
