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Thread: turbo woes...

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Posts: 21-30 of 41
2012-04-12 13:59:42
Weird indeed! Keep us posted .
2012-04-13 02:47:42
Idk what is wrong with this thing. I sprayed starter fluid all over the damn intake manifold to no avail... Idk where the leak is...
2012-04-18 04:55:38
The difference in vacuum can be caused by the idle timing feedback loop. If base AFR is way off it may be adjusting timing a lot to maintain the target idle speed, which can affect vacuum. Does it run better cold or hot?
2012-04-18 06:37:35
Well, it varies. Sometimes it won't idle for shit when it's cold. Sometimes it will idle fine. Sometimes it idles fine when it's warm. Sometimes it won't.

You bring up a good point, however, I'm more likely to believe its a leak somewhere. I'll have the intake manifold back on with new gaskets tomorrow. I'll get it started and see how it runs. If the issue persists, then I'm gonna need a new chipset with a better tune.

I also have a quick question for you guys;

When Calum did my ecu and the base tune, he tunes it for 4 bar fuel pressure. I do not have an adjustable fpr on the car and am still running stock fuel pressure. I don't believe it would affect anything, but am unsure. What issues would this cause?
2012-04-18 07:58:20
it will run richer and prob like shit
2012-04-18 13:22:16
Do an intercooler pipe leak test, you'll be surprised at couples that are leaking (I definitely was!)

4 bar tune on 3 bar FPR is no go either. 4 bar tune is 420cc technically, 3 bar is 370cc. Richy-rich-Mc.Richie
2012-04-18 15:13:24
Replace your coolant temp sensor and your plugs. I had a hairline crack in one of my plugs causing me to run stupid rich all the time. I couldn't figure it out till finally I took a good look at my plugs. My coolant needing to be bled cause of a leak didn't help either
2012-04-18 15:57:00
I just installed brand new bkr7e's two days before I pulled the manifold off. I'll look into replacing the sensors. I have a new one for my auto meter water temp so I'll install that too.

Does anybody have an adjustable for they want to sell me? Preferably not one that's on a cost me a bunch lol. The funny thing is that I didn't even ask him to tune them for 4 bar he just did it. But my VE is tuned 4 bar with VE injectors and it runs perfectly fine on 3 bar fuel pressure...

I'll have to rig up something to test my piping but I know it's after the maf, which there are only two couplers.
2012-04-19 23:30:24
Originally Posted by morgans432
it will run richer and prob like shit

Sorry, but this is wrong. Heres why...

You can effectively make an injector 'bigger' by increasing base fuel pressure. In fact, the rated size of the injector is only correct at a specific pressure. So if an injector is 370cc @ 3bar, it is essentially a 420cc injector @ 4 bar (at least according to this - RC Fuel Injection ). Point being, a 420cc injector will outflow a 370cc injector at the same duty cycles.

That being said, if the tune was designed around a 370 cc injector @ 4 bar, but only 3 bar of fuel pressure is being used, it will run lean (relative to how it was tuned). This is because the tune has no clue that you are running lower pressure. The tune expects a certain amount of fuel to flow during a specified injector opening, but because the pressure is lower not as much fuel flows during the same injector opening.

At this point you should get a wideband. You can get them for under $200 now (I like the AEM UEGO, but to each his own). I finally got one and I wish I had done it years ago. Without it, you are in the dark as to what is going on with fuel. They can really be useful for diagnosing all kinds of problems, even if you can't adjust the tune.

Good luck!
2012-04-19 23:49:24

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