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chris164935

Tuning Issues

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Hey guys.  The car is a 2001 Audi A4 1.8T (same as Audi TT 1.8T motor).  I am using the Vi-PEC i88 ECU.  I am relatively nnew to the stand-alone engine management world and am learning as I go.  I started with the Audi TT base file and modified it for the sensors/injectors/etc. that I am using on my motor.  It starts up on cold starts and warms up just fine.  However, trying to give it throttle, the engine stalls out (even light taps).  I am using a larger throttle body (80mm versus stock 60mm).  I imagine I need to change some settings to compensate for this.  Or, perhaps it is something else?  Can anyone point me in the right direction of where I might start?  I would like to have the car tuned professionally at some point, but I need to get the car rolling first. :D

The other minor issue I am having is that the car does not seem to want to start again once the engine is warm.  What are some of the settings I can adjust to help with warm starting?

I have attached my *.pclr file so you can go over the current settings.

Thanks!

B5 A4.pclr

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Hi Chris,

Is the larger throttle body still an e-throttle body? If yes, have you re-done the TP calibration process?

Have you set the Triggers Base Timing up using a timing light?

Normally when the engine is starting and already up to temperature it is going to require less fuel and idle air.

Can you post a PCLog of you starting the engine, leaving it a moment, and then applying some throttle that causes the engine to stall? This will help us see what is happening.

Scott.

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Thanks for the reply Scott.  Yes, it is an ethrottle body.  I have done TP and AP calibration.  I am using the trigger timing based on what was provided in the base TT file.  No trigger errors.

I'll try to get some logs tomorrow.

So, for the warm starting, I just need to adjust the Fuel Table 1 values at the low RPMS (approximately 0-1000) when MGP is at 0?

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Hi Chris,

If possible try and get hold of a timing light so you can confirm the base timing is correct. 

For the warm starting check the that no warm-up enrichment is being applied when engine is up to temp. If you go to the fuel tabl of the runtime values window (F12 key) you can see all the trims being applied by the ECU. I would expect the cold start settings from our Audi TT base-map would be pretty good.

Does holding the throttle slightly open help when trying to start at warm engine temps?

Scott.

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Scott, slightly opening the throttle body did not help the previous times when warm starting.  I have adjusted some settings on the ECU now, but, unfortunately, can't start the car because sleeping neighbors.  :lol:  I will let you know how it goes tomorrow and get you a log file.  Thanks!

Edited by chris164935

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Ok cool, I'll look out for the log file. If slightly opening the throttle body did not help then it is likely the idle control is ok and it is the fueling that needs adjusting.

Scott.

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Okay.  Had a bit of a hiatus because I needed a new battery.  Also I fixed an issue with the Ethrottle so it is operating correctly with no faults.  I have not really changed much in terms of the tune though, but the car is not cold starting now.  Sometimes it will catch and idle rough for about 30 seconds but eventually, it stalls out.  Leaving the fuel table at the base TT tune numbers is when it has the best chance of starting; if I try to pull fuel, it won't catch at all.  I have attached the tune I am using for my setup and a log file of attempting to start the car a few times and it idling a couple times before stalling out.

EDIT:  Tapping the throttle just makes the car stall out as well.

Log 2016-08-4 1;57;01 pm.llg

B5 A4.pclr

Edited by chris164935

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Have you done the trigger calibration with a timing light per Scott's suggestion earlier?  Your MAP is >100KPa at idle - if an engine like this cant pull decent vacuum at idle then most likely either ignition timing or cam timing is out.  It also seems odd that MAP is higher than BAP at idle?  Maybe your MAP sensor is connected wrong or not calibrated correctly?

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I have not tried much yet other than attempt to start the car.  I wanted to get a log first and see what you guys think.  Unfortunately, timing of the motor might not be as simple as checking it with a timing light.  I have aftermarket camshafts that did not have any timing marks and required to be manually timed.  I am hoping to eliminate any potential issues with the tune before I dive back into the motor and check all the timing again.  The car has started and idled normal before (2 out of the 3 times I started it up back in June).  Perhaps the MAP sensor was toasted when I had battery issues?  I did perform a MAP calibration before logging and it was reading 0.1 PSI higher than the BAP with the car off.  I have a spare MAP sensor that I can install and see if that helps.  Also, the ECU is storing no fault codes except AN Volt 1 being too low.  But, this code is temporary as AN Volt 1 is my O2 sensor and it is connected to a 12v load reduction source ( so it is off when the car is cranking).

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Trying to tune any fuel or ign table before you have the basic requirements of a running engine in place is pointless.  A log is worthless when we cant trust any of the data that it is showing. 

The first thing you must do is verify the ignition timing.  If you don't have easily accessible TDC marks on the pulley or flywheel, then paint on something temporary using your best guess at TDC based on something like a screwdriver down a spark plug hole - not accurate but at least that will verify if you are in the ball park.  Similarly, cam timing is also easy enough to do a reality check on.  At TDC exhaust stroke, both intake and exhaust valves will be open a similar amount and it should be relatively small - say 2mm lift.  MAP sensor is also easy to verify; Suck on the hose with your mouth - you should be able to get down to say about 50KPa (guessing?), blow on the hose you should see ~110KPa.

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Cam gear has a mark a TDC, and the valve cover has a notch/mark where the cam gear TDC mark should line up.

Crank also has a mark against the front main seal, and the crank gear lines up with this mark accordingly.  

Even if your cams haven't got a clear mark on them for timing, there are requirements for the chain and chain tensioner at the rear to be at a required interval (16 links inclusive of marked cam caps  -  there's heaps about timing a 1.8T motor on the web).  Waht type of cam gear are you using?  If standard, then the keyway lines up according to the way the factory would.

 

Are you using all the same sensors for the 06A motor?  This isn't a bitsa by chance (AEB big port head on later 06a block, etc)?

I'm building another motor, using the Vipec plugin i88 as offered before the re-branding.  Had zero issues with triggers and timing the motor.  Need to make sure all your sensors are for the 06A motor, even timing gears etc.

 

 





 

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AEB head on 06A block.  Everything else is 06A:  both trigger sensors, IAT sensor, ECT sensor; cam gear is 06A (aftermarket); camshafts and valvetrain are 06A (aftermarket).  MAP sensor is an AEM 7.5 bar.  All sensors are brand new.  The trigger wheel on the intake camshaft is the 1-window from an AEB head.  I am using a non-VVT tensioner.  I am aware of the timing marks on the crank gear and camshaft gear.  Neither of the camshafts have actual timing marks to align to the cam caps at the back of the head.  We had to manually measure the lift of the intake camshaft to find the proper timing.  Exhaust camshaft was timed via the camshaft gear marking and crank was timed via measuring TDC with a piston stop and degree wheel.  The motor builds great compression for a freshly assembled engine.  I am using the trigger settings from the base TT tune.  Like I said, the car has started up and idle fine before.  The motor even got up to operating temperature while idling.

Edited by chris164935

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I stand to be corrected, but the base file for the TT was derived off an 06A motor, using an 06A cam sensors/triggers (hall effect) and not the 058 AEB one...  Maybe try swapping this over and seeing if your ignition signal returns?  Just because you're not using the VVT off the 06A, it doesn't mean you need to use the AEB wheel.

 

Mike.


 

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Well, I got it figured out.  Trigger calibration was correct.  Didn't have to play with any of that (And I'm still using the AEB 1-window trigger wheel for the cam position sensor).  The issue was the base TT tune is not good enough to get my setup to start (1000cc injectors).  I took the fuel table settings and fuel crank settings from the G4+ Atom sample tune (setup for 1000cc injectors).  She fired right up!  Idling is a little sporadic still (needs more fine tuning), but I was able to drive the car around the block and piss off my neighbors.  Lol.

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Alright, some updates.

Went ahead and did the timing light procedure and got that all sorted out.  Disabled Accel Enrichment and Overrun Fuel Cut.  Car starts and idles poorly.  The car is not holding the idle I would like it to (850 RPMs) when the car is warm (Car is rough idling on cold start too, but not as bad as warm idle).  It stays around 1100-1200 RPMs.  At this point, the motor starts running really rich and when you give it gas it starts backfiring a lot.  This gets the turbo/downpipe/manifold glowing red hot in no time!  While idling/trying to drive from a stop, the motor runs horribly.  Once that clears up (if it clears up) and the car is driving at a normal speeds, it hold the correct AFR and drives like a champ; like, smooth as butter when cruising/part-throttle driving, accelerating, and shifting gears.  Also re-enabled Accel Enrichment and Overrun Fuel Cut and got that sorted out.  But, either way, it is just at idling the whole thing starts to fall a part.  I have attached my file for review.  Currently, at idle, I have the throttle body set to open to 5% at 0% gas pedal.  Any lower and the car stalls out.  But, this kills almost all vacuum (throttle body is 80mm).  And so, on Fuel Table 1 at 0 MGP between 750 and 1000 RPMs, that is where the ECU reads fueling.  Currently, 0 MGP at 750 RPM is set at 100, which makes the car run rich.  But if I start to lower it at all the car stalls out almost immediately.

B5 A4 1-14-17.pclr

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