vp berlina v6 drinking fuel

[hi_ryder]

ive hooked the car up to efi-live pro V4, and ive got no error codes at all. im only getting 300 k's from a full tank and i dont know where to look next. can anyone help with the data if i post up some screen shots? any help would be great. oh also the o2 sensor was replaced 2000 k's ago... cheers...

[hi_ryder]

so if theres no error codes coming up what could be using up all the fuel. injectors? transmission problem? ca nthe o2 sensor be dead and not come up as an error code?

[jenner45]

What fuel do you use? Normal fuel gets guzzled in my vs but I get a lot more out of 98 octane

[hi_ryder]

were talking 300 k's from the berlina versus 500+ out of my calais. same engine same everything. ive run 2 full tanks of 98 through the car in the last 2000 k's and got the same results... im going to run some injector cleaner through it and see what happens. if the injectors are anything like the state of the spark plugs when i did a tune up i bet there buggered. the plugs were so far gone it was idling like i left a couple leads unplugged...

[hi_ryder]

so i just went down to super cheap for some injector cleaner. parked and got out of the car and was looking around sniffing. i smelled petrol so i popped the bonnet and sniffed like a blood hound and inspected all the connections.

everything looked good so i went around to the back and looked under the car and what do you know, petrol is dripping on the ground. looked like it was coming from the connections off the fuel pump assembly. bought some new hose clamps and what the hell injector cleaner too.

i jacked up the car and put it on stands and started the engine. cleaned off the gunk with a piece of scotch brite and wiggled the lines while the pump was on see if i could get it leak somewhere. no joy. i replaced the clamps and tightened the bolts to the fuel pump assembly and dumped in the injector cleaner in the tank. makes me wonder how much was being lost that i wasnt aware of....

ill post an update next week.....

[hi_ryder]

diggin my own thread here. ok still drinking fuel..... this is my question, ive plugged it into efi live and my coolant temp sensor when the car is running hot says 98 degrees C. that dosent seem right because the engine is super hot seems like way more than 98 degrees. think there should a new coolant temp sensor in the vp's future? - or is that temp reading seem normal. any help would be appreciated...

question 2 is the "O2V" reading gauge reads 0 to 1000 (im assuming millivolts) its fluctuates from 300 to almost 1000, is that normal?

[vamplestat]

just a quick question, but how do you drive? abit of a lead foot or normalish style. and what base tune is your car useing? and when i get the chance i will check my calais tomorrow for some readouts and see if there is any real difference in the numbers you have given.

[VRV694]

98 degrees is fine,i use efilive v4 on my vr as soon as it hits 100 the thermo should cut in.

[Jxw]

how about the air temp? both those sensors can play havoc on fuel, although reading 98deg for coolant the ecu wouldn't be running rich as that's about normal operating temp.

mine coolant temp sits around 83-90 degrees out on the highway at 100-110km/h


Not sure if this will be much help but here's some readings from a vr v6 (close enough to a vp v6) from a 20 degree day, should show a rough correlation between coolant and manifold temps, from cold start to 95 degrees, letting the engine idle without touching the throttle to get up to temp, no cai and factory bit from the airbox to headlight removed.
Gets over 500kms per tank round town.

Coolant °C	Air °C	time M:S
18.5	20.8	0:00
47.75	30.5	5:00
68.75	30.31	10:00
82.25	53.75	15:00
92.75	62.75	20:00
95.00	65.75	21:46

[VPRob]

VR motor in my VP. Round town I'm doing well to get 300ks out of a tank. New plugs, new air cleaner, good transmission. Wish I could get better. I'll keep watching this thread 4 ideas.
Have you checked the fuel return valve at the end of the fuel rail? My daughter's VP was sucking fuel back into the engine (instead of returning it to tank) cos the vacuum vellum had a hole in it. We could smell fuel under the hood but took a while to find. Worth a look

[hi_ryder]

just a quick question, but how do you drive? abit of a lead foot or normalish style. and what base tune is your car useing? and when i get the chance i will check my calais tomorrow for some readouts and see if there is any real difference in the numbers you have given.

i purposefully drive easy to give more accurate results on the fuel economy, right now im doing nearly 20 litres per 100k's...

how about the air temp? both those sensors can play havoc on fuel, although reading 98deg for coolant the ecu wouldn't be running rich as that's about normal operating temp.

mine coolant temp sits around 83-90 degrees out on the highway at 100-110km/h


Not sure if this will be much help but here's some readings from a vr v6 (close enough to a vp v6) from a 20 degree day, should show a rough correlation between coolant and manifold temps, from cold start to 95 degrees, letting the engine idle without touching the throttle to get up to temp, no cai and factory bit from the airbox to headlight removed.
Gets over 500kms per tank round town.

Coolant	Air	time
18.5	20.8	0:00
47.75	30.5	5:00
68.75	30.31	10:00
82.25	53.75	15:00
92.75	62.75	20:00
95.00	65.75	21:46

does the vp have an air temp sensor? if so where do i find it, and does it have a value in efi live? thanks for the reply as well dude, any little bit helps...

VR motor in my VP. Round town I'm doing well to get 300ks out of a tank. New plugs, new air cleaner, good transmission. Wish I could get better. I'll keep watching this thread 4 ideas.
Have you checked the fuel return valve at the end of the fuel rail? My daughter's VP was sucking fuel back into the engine (instead of returning it to tank) cos the vacuum vellum had a hole in it. We could smell fuel under the hood but took a while to find. Worth a look

ill have a look at that return... cheers
i think ive fixed all the leaks in the engine bay, there were a few loose clamps and what not. also ive just installed a set of reconditioned injectors last week, with no change to fuel economy. i can smell fumes from the petrol tank once in a while so i changed what i thought the problem was which was a dud petrol cap. im using a vt cap now cause the old one didnt make a good seal over the filler neck.

after changing the injectors im getting error code 42 which is electronic timing circuit bypass. i had a spare computer in the garage as well as ignition module. ive spapped both out with no change. on one run i did i got both error 42 then error 43 (knock sensor). it only pops up about 10 minutes into cold startup then disappears. (engine light comes on then goes off) i know its not the computer or module so could the knock sensor trigger the code 42 and not log itself in the process? only had the knock error once though....


i also found this and did an inspection on my wiring for any trouble http://wiki.answers.com/Q/GM_Scanner..._do_you_fix_it

[Jxw]

does the vp have an air temp sensor? if so where do i find it, and does it have a value in efi live? thanks for the reply as well dude, any little bit helps...

sure does, VN VP VR it's at the back of the intake manifold on the drivers side, i've cleaned the carbon off (pain to do and uses a fair bit of degreaser) a couple and they tested fine, others replacing was the quicker option.
same testing procedure as the ecu temp sensor with a pot of water on the stove, thermometer and a multimeter to measure the resistance at certain temps.

in efi live right click a gauge, problem with this is if the sensor is buggered it'll show a reading but it may not be accurate, best to remove and test, basically unless the sensor shorts or goes open circuit it won't throw an ecu error code so the ecu will just fuel away to whatever temp it thinks the engine is at.

vn/vp: caption -> attribute -> mat (gmh-vn68vp68.xml)
vr: caption -> attribute -> intake (gmh-vr68vs8.xml)


be careful removing the plug, as they're old the plastic can be brittle and lifting the unlock tab to far can break it off


Gregorys say to Immerse the sensor tip in a 50/50 glycol/water mix and heat slowly for both sensors, i've done it in straight water with no ill effects
i'm also lazy so i measure them at room temp then bring the water upto boil and only check 2 or 3 measurements, they may not be exactly this but as long as the resistance correlates to temp approximately.

Cts
Temp °C	Res Ω
0	6000
20	2500
30	1800
40	1200
70	450
90	250
100	190
110	110

MAT
Temp °C	Res Ω
4	7500
20	3400
38	1800
70	450
100	185

[hi_ryder]

so to measure the ohms resistance id need a multi meter? i should just take it off and clean it with degreaser? i ran the car for a couple of minutes and when the coolant temp got to 100 the mat value was 45 on efi live dashboard. on dead cold the coolant was 30 and mat 8. i noticed even with the car idling normal the o2v was like 900. that means its running super rich if im not wrong...

any ideas on the error code 42? im still getting it even after a 7 min drive. ive changed both computer and module. could it be the leads are too close to the ignition module? those plastic clips broke and the leads are just sitting on the engine instead of up and out of the way....

[Jxw]

dead cold the 2 should be close to each other as they'd both be in theory at ambient temp, maybe a couple of degree's difference but not 22 degrees, if it's registering a much colder temp then it'll cause it to run rich, i'd replace it if the values were that far apart.

42 could be an issue with the dfi module under the coils, do you have another to try? even swap it with another car and see if the code shows up on the other car, i'm pretty sure 42 was 1 of the probs with my brother's vt (had about 3 codes), was still running but a bit rough and would occasionally stall, was like it for a year or more till i got my hands on it to check, he replaced that and it's running 100% better, i got the parts that were replaced and tested them on one of my engines and it threw codes on my car as well.


Does it have one of those ebay bullshit performance "chips" on it (an out of place black box near the mat sensor)? cause that's exactly what they do, skew the mats value n stuff up the fuel economy

[hi_ryder]

as far as im concerned the only mods to the car were kings springs and what use to be a monster audio system... everything else is rock stock...

and the ignition module has already been changed with the spare i had in the garage. computer too... maybe my spare is buggered as well... might go to the wreckers and dak a few and see if they throw codes as well... ive got 2 vps and a vn so theres plenty of ones to test....

the other thing is ive got 5 recoed injectors in right now, one of them failed and i sent it back and im waiting for the new one to come, so theres an old one still in right now. wonder if that could be the problem as well....

thanks for the help man ill order a new air temp sensor asap and see what happens....


aca catalogue lists this one for most commodore models, should be good to go...

http://purchasenet.com.au/shopping/e...ug-p-1117.html

[Jxw]

maybe the cas causing it then if you've changed the dfi, doubt the injectors would cause it, only thing you should get from a fueling issue is lean/rich o2 readings and possibly excessive pinging if it's lean under acceleration.

that sensor looks about right.

[hi_ryder]

might be due for a balancer as well, the one it has looks dry rot around the rim, it has cracks... might do both as the same time...