VEMS 1.8t 630cc coldstart problems

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Urtorsen
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VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

I'm in a bit of bother and I can't get a hold of kevin black, just wondering if any of you guys in the colder states have a few cold start files that I could look at, it's Baltic here in Chicago the past two days

I had it starting and running good just tweaking the fuel from base but the coldstarts and afterstarts are crap but i was able to get past them by holding the throttle for a minute then it would idle really low.

now that it's even colder it doesn't want to get past cranking, the plugs were wet last time I checked but I have spark. I'm gonna put fresh plugs in but I need assistance or a file to compare it to.


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

Or if anybody could look at my config and try to see what's going on


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UrSobsessed
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Re: VEMS 1.8t 630cc coldstart problems

Post by UrSobsessed »

Post a log so we can analyze what you gots goin on...
Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

Ok


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88a5tq
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Re: VEMS 1.8t 630cc coldstart problems

Post by 88a5tq »

Does it start and then rpm's drop suddenly until it stalls just seconds later?
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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

Yup


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

The iac is setup with timing, but the dc values are all 0, it's just a basest so trying to get it easier to live with untill kevin at lugtronic gets a chance to tuning it


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

Ok so I was able to improve the coldstarts but I'm having problems with the idle never reaching the target 850 rpm, always 1000 when fully warm after driving

I put iac ref all at zero, the PID are all zero. the timing I can drop it to 8 deg in the idle blocks, the lambda is perfectly on target everywhere, (I calibrated it to air again to be sure) no joy in getting it lower. The idle advance can't get it down either.
The AEB head was ported and polished by USRT. The cams are stock. Stock 1.8 displacement.
The idle is steady and smooth, never stumbles when I have the idle ign advance on or off. The car is smooth to drive under day to day driving, in and out of boost, deceleration etc. the vacuum is always 35-36kpa at idle and I checked for obvious leaks, nothing.
The crank gear is pinned and the cam gear is stock. As is all the other hardware. Just doesn't seem to want to idle slower than 1000 when at running temps.




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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

If I drop the fuel to get my idle the lambda goes way up out of scale 1.20+


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loxxrider
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Re: VEMS 1.8t 630cc coldstart problems

Post by loxxrider »

Maybe you're going the wrong way with fuel... Too lean will make it idle high.

Also, have you tried the physical adjustment on the throttle body?
-Chris

'91 Audi 200 20v - Revver/BAT project
'91 Audi 200 20v Avant
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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

As it warms up (past the warmup upper set point)is the lowest it gets , 900-920 rpm, when it gets up to the 80c + temp it's 1000-1080 all the time


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

If I give it more fuel it starts to idle higher


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

I didn't mess with the throttle body at all. Damn!!! Maybe when I put the throttle cable back its holding it slightly ajar letting too much air past?


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

Gonna check this right now to see if I can let the plastic adjustment back, hoping this will solve it, always overlooking the simple things!!!


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

Just checked, it's got play in the cable.so throttle is at zero. It's a stock AEB TB, is there other adjustments???


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Urtorsen
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VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

It looked clean last time I checked too, I'll take off the silicone to have a look Incase.


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Urtorsen
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VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

Would the fact that I use a BOV to atmosphere cause this? It doesn't open at idle.
Do dv/recirculating valves open at idle, maybe that's it??


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loxxrider
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Re: VEMS 1.8t 630cc coldstart problems

Post by loxxrider »

The BOV shouldn't matter as long as it is before the TB.

What is AFR or lambda when you are adjusting it to be richer and the idle goes higher?
-Chris

'91 Audi 200 20v - Revver/BAT project
'91 Audi 200 20v Avant
'01 Anthracite M5
'90 M3
'85 Euro 635csi
'12 X3
E34 530i (maybe rear-mount soon)
Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

The target is 0.96 , if I keep on making it richer it will keep going on into the high 80s along with it.


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

When I got the base file it was lean outside 1.29 on idle and never on target, so I bumped the req fuel and played with the table and it's spot on everywhere now.



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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

It's not stopping me from driving or anything but the target rpm is 850 so the iac is constantly working to achieve it if enabled. It's just bugging me as I know they idle around 750-850 in stock form.


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Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

The only thing that lowers it is bringing the advance in idle blocks down but I stopped at 7.5-8 deg as it shouldn't need to be that low??


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loxxrider
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Re: VEMS 1.8t 630cc coldstart problems

Post by loxxrider »

What happens if you unplug the IAC?
-Chris

'91 Audi 200 20v - Revver/BAT project
'91 Audi 200 20v Avant
'01 Anthracite M5
'90 M3
'85 Euro 635csi
'12 X3
E34 530i (maybe rear-mount soon)
Urtorsen
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VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

The timing mark on the 1.8t cam is always 1/2 tooth off to put on the belt. As most people do , I move it the 1/2 tooth clockwise (advance ) to put the belt on, If I move it to the opposite direction would it make enough of difference??


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Last edited by Urtorsen on Fri Feb 06, 2015 10:27 pm, edited 1 time in total.
Urtorsen
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Re: VEMS 1.8t 630cc coldstart problems

Post by Urtorsen »

The iac is built into the tb , so it's on the same connector, I will try it, to see what it does


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