Calibrating a 4 cylinder engine

For discussion and distribution of custom code and hacks
User avatar
Holden202T
Posts: 10308
Joined: Sat Feb 28, 2009 9:05 pm
Location: Tenambit, NSW
Contact:

Re: Calibrating a 4 cylinder engine

Post by Holden202T »

yeah on whatever the item is your wanting to change
POZE
Posts: 33
Joined: Sun Feb 26, 2012 8:53 am
cars: GN

Re: Calibrating a 4 cylinder engine

Post by POZE »

I'm having a problem with stalling when coming down to idle. It shows a TPS stuck code 19. When reviewing the logs I see TPS volts change with throttle movement but the TPS percentage stays at 0. I cannot see any patterns that point to certain conditions, it appears to be random. Any thoughts?
Thanks
POZE
Posts: 33
Joined: Sun Feb 26, 2012 8:53 am
cars: GN

Re: Calibrating a 4 cylinder engine

Post by POZE »

I also noticed battery voltage is erratic. It will drop by 4 to 6 volts at times when reviewing logs.
Are these signs of a corrupted Bin?
davidthiele
Posts: 17
Joined: Sun Apr 08, 2018 12:38 pm
cars: Turbod 1972 VW Beetle with very modified suspension and brakes, Transit van getting a VY V6 conversion

Re: Calibrating a 4 cylinder engine

Post by davidthiele »

I just found this post - very late I know. You stated at the start that you were using 20psi fuel pressure. That seams very low as most EFI engines use approx 45psi (3Bar). Not sure if you ended up sorting it all out but low fuel pressure would give you lots of dramas.
Cheers
David
BennVenn
Posts: 468
Joined: Fri Mar 04, 2016 10:35 am
cars: R33 GTST, '60 Vw Bug, Express (4G63T), GW X200
Location: Windellama, NSW
Contact:

Re: Calibrating a 4 cylinder engine

Post by BennVenn »

The TBI typically runs 17-20psi rail pressure so I don't think that's the problem here.

I've got a tune here for a TBI 1.6 using 12P. I got it close but it was never quite right - I don't think the algorithm it uses is suited for TBI setups. I tried it on my bug and on a 1.6 Pulsar. I'll fetch it from my laptop later today if it'll help.

You will need double fire always on, you will need to set the memcal to 2cyl TBI mode or else it'll only fire every second dizzy pulse which is not suitable for a TBI. Reported duty cycle is half of actual duty and AE never worked as well as it does on multipoint. I remember having to use unusually large AE numbers to try remove that hesitation / lean afr on cracking the throttle. A super rich idle (~13 or lower) helped but that came with its own issues.

For the VW I ended up using the stock pulsar/astra TBI tune and adjusted the fueling and timing. The AE and pooling issues were still there but not as severe as 12p. I ended up changing to multipoint and all those problems went away.
User avatar
antus
Site Admin
Posts: 8228
Joined: Sat Feb 28, 2009 8:34 pm
cars: TX Gemini 2L Twincam
TX Gemini SR20 18psi
Datsun 1200 Ute
Subaru Blitzen '06 EZ30 4th gen, 3.0R Spec B
Contact:

Re: Calibrating a 4 cylinder engine

Post by antus »

It does work for TBI fine. We based our TBI on Charlescrown and after tuning VE and Spark (stock injectors) it runs perfectly. viewtopic.php?f=26&t=6786&p=100922#p100922
Attachments
20210311_230643.jpg
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
BennVenn
Posts: 468
Joined: Fri Mar 04, 2016 10:35 am
cars: R33 GTST, '60 Vw Bug, Express (4G63T), GW X200
Location: Windellama, NSW
Contact:

Re: Calibrating a 4 cylinder engine

Post by BennVenn »

Perhaps it's more related to manifold design, length and probably more Important - heating than 12p not being well suited to TBI.
Post Reply