some questions

[methodwares]

Picked up my new car a week ago, my second cerb, first one was lost due to an unfortunate meeting with a lamp post after a rear shock failure a year and a half ago.

there were some issues on the inspection report so i started looking at the 'easy to fix' ones last night. i have some questions as a result.

first, there is a vacuum line running off the back of the passenger side air box into the bulkhead below the wiper motor. what is this for? I only ask because the little plastic connector in the airbox has come loose and as a result would not be giving a true 'signal' to whatever this is hooked to.

second, tied to the clutch hydraulic line there is a second steel braided line with the open connector near where the first one comes out of the wing. what is this for? it wasn't on my other car, or if it was, it wasn't tied up like this.

third, the report mentioned a possible imbalance between the individual throttle bodies. to check this i would need to get an airflow meter, where can one of these be purchased? and how would one go about adjusting the individual throttle bodies? I know how to balance the banks so that isn't an issue.

and finally (for this post), the screws holding the throttle bodies to the rods, on 6 out of 8 tbs, one of the two screws looked like it had a small hole drilled through the center of it. I didn't have anything handy to poke the hole with to see if it does go all the way through. Is there a hole there or does it just look that way?

thanks

john

Edited by methodwares on Saturday 28th October 07:41

[mike_e]

1) I think the vacuum tube is something to do with the manifold ambient pressure sensor.

2) The braided hose is the bleed nipple for the clutch.

3) Don't think you can individually adjust the throttle bodies, only the banks.

4) No idea, all looked the same to me.

Use the search facility, absolute mine of information.

[ridds]

Small hole is for fine balancing of the air flow on each tb I think, probably trying to sort issue 3.

[methodwares]

1) should i put a silicon seal to 1. make it sit in there better, and 2. give a better reading?

2) makes sense, had a feeling thats what it was...

3,4, ridds) forgot to mention its a 4.2. my last was a 4.5, i remember shane at sfr said that the tbs between the two halves of the banks could be adjusted individually, (i.e. 1 and 3 could be adjusted separately from 5 and 7) is this possible on the 4.2? or as ridds says, the funky screws might be there to sort out the problem, which to me would mean if i can't get the balance close, then pull the manifolds off and get them flow balanced on a bench, tho that does seem a bit overkill.

thanks

ps. is search working again? last time i checked it was still google which, well, doesn't work as well as the regular one. i'll have a look in the morning

[350matt]

Usually you only have to balance the throttles side to side using the throttle link bar, I'd reccommend getting yourself a copy of the software and with the engine running you adjust the throttles so that the fuel multipliers are the same on both sides then re-set the throttle position sensors so they both read 15ish

All the exact numbers are in the help file on the software

If you need a copy drop me a mail



Matt

[methodwares]

I have a copy, just need to get a usb to serial converter or an older laptop. and the time to do it. thanks.

[Nickccc]

methodwares said:

I have a copy, just need to get a usb to serial converter or an older laptop. and the time to do it. thanks.

I would go for a PCMCIA to serial, some here have had problems configuring the USB one.
Also this is the set up Mark Adams reccomends.

Nick.

[methodwares]

i'm borrowing a converter from work, i'll see if it works tonight. i may have to get an older (el cheapo) laptop anyways as the project I was on that required the one i'm using now has been canceled and the new md has been eying it up. its a pretty nice sony viao 17 inch wide screen, and the lcd looks like a plasma screen tv, f'in gorgeous

[methodwares]

the USB to serial converter worked, had to configure the port to COM1, hook the cable up, turn on the ecu and press the reset on the converter box.

although i didn't have time to adjust anything last night, i did notice the throttle pots were not set correctly for zero throttle (idle) and not equal. also the odd bank adaptive numbers seem pretty bad (ranging -30 to -10) where as the even bank seem fine (+2 to -8). something else that was interesting, is although the t-pots were not the same at idle (a difference of 2ish), once they got over 45 or 50, they were the same all the way up until full throttle where they got to 87. should they be set up to be the same at low rpm where the lamda readings are used?

thanks

john