# c2 42# ABA program breaking up at 18psi



## wide_mk1 (Aug 13, 2007)

I just got a brand new garret t3 super 60 to replace the t3t04e that i was running. the turbo is amazing, it spools much quicker and the power delivery is much more linear/ "fun to drive." 

With my manual boost controller all the way down, the boost spikes at 18-20psi and holds at 17psi at WOT. 

I am having a problem at WOT. The motor breaks up really bad at high boost. It is fine anywhere up to 15psi but above that (which occurs at WOT) it breaks up. With my prior turbo, the highest boost I ran was 15psi so I never ran into this problem. The car ran fine before under boost with no "breaking-up" issues at WOT. 

My guess is that I am running out of fuel. I am running this setup in an 84 rabbit with the stock CIS fuel pump and the stock ABA 3bar FPR (which c2 recommends for the 42# program). 

I am going to get a fuel pressure gauge so I can give an exact reading but from anyone's experience, could that be the most likely culprit? 

If that is the case, should I get a 4bar FPR or an in-line fuel pump? 

Thanks in advance.


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## 976-RADD (May 29, 2003)

What wastegate are you running? You could have too weak of a wg spring, ie. 7psi spring.


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## MaxVW (Nov 4, 2004)

you will max the injectors somewhere near 16 psi, be careful you will lean out after that. it will missfire when you go lean like that


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## BoostedDubVR6T420 (Dec 4, 2009)

You should definately invest in an in-line pump? Most likely getting misfires up top and you are breaking up. What gap and plugs are you running?


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## danz44 (May 14, 2010)

find someone with a wideband air fuel ratio gauge, verify the AFR is good, verify you arent losing fuel pressure... if pressure stays solid and AFR is good, check your spark plug gap. 

you might be blowing out the spark. 

18psi from a super 60 should be around the 250-275whp area on a good setup 

edit: your injectors should be good for that much power. not sure about the fuel pump...


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## rweird (Apr 10, 2004)

m


MaxVW said:


> you will max the injectors somewhere near 16 psi, be careful you will lean out after that. it will missfire when you go lean like that


 no. you will max the injectors at around 300whp. psi from one turbo does not equal psi from another. i was running ~22psi from a 50trim t3t04e which is a larger turbo that a t3s60. 
hell i was running 14psi on a t3s60 on stock compression. 

you would really pushing the efficiency of the super60 to hit 300whp.:thumbup: 
check the wastegate spring, what plugs?, what gap?, check afr, inline pump or replace the cis pump with a mk3 pump:thumbup:


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## wide_mk1 (Aug 13, 2007)

wow, ive never gotten so many responses so quickly, thanks everyone. 

Here is the setup: 

t3s60 
2.5" intercooler piping with big-ass intercooler (it was cheap) 
bosch 42# green-tops 
c2 OBD1 ABA 42# Tune with 3" VR6 MAF Housing 
NGK-BKR7E Plugs gapped about .028ish 
Stock 3 bar ABA FPR 
2.5" exhaust straight out (side exit) 
Stock 84 Rabbit CIS Fuel Pump 
Stock Ignition (wires, coil, etc) 

Like I said, it ran fine before with the bigger turbo. 

I had some issues with it breaking up at higher rpm's before but the gap on the plugs was around .035 and after closing it down it ran fine. 

I am thinking its running out of fuel but I am also concerned with the boost pressure. 

I am using the internal wastegate that was on the turbo from Garrett. I am assuming that it would run a low boost (6-10psi) with my MBC all the way down but it hits muccchhhhh harder than I would like it to at low boost. 

It is a street car and I am not looking to make any more than 250ish horsepower. I want a fun to drive, reliable car more than a drag-racer that breaks every ride around the block. I feel like I am there with this setup but I just need to work out this kink. 

Strange, I gotta go more wrench time on the car...its just a matter of making the timmmmmeee


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## rweird (Apr 10, 2004)

tighten up the plug gap alittle. .024 
i also have a innovate xd-16 gauge and lc1 wideband for sale. lmk


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## Stroked1.8t (Jan 9, 2004)

you went with a smaller turbo and you think you are running out of fuel. I would think just the opposite. in my experience gasoline has more a tendency to break up/misfire when it is rich, when it goes a little lean it still fires clean just with less power. 
what trim was the t3/t4 and the C2 tune you have is for this t3/t4? 
also from what I remember about the CIS Pump, it is the pump to have, capable of supporting 500HP. 

a new chip is likely the answer to your problems. you have enough injector and enough pump.


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## rweird (Apr 10, 2004)

chip is fine. it doesnt care what turbo youre running.


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## wide_mk1 (Aug 13, 2007)

i agree with stroked1.8t and rweird 

i would say that i am probably going very rich and i need to confirm that (wideband will be here friday) 

i do get a feeling that the chip will be fine regardless of turbo since the injectors and maf housing are matched to the chip... 

i am going to look into plug gap, afr's, and get my wastegate situation under control (maybe i need a new mbc)


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## B4S (Apr 16, 2003)

Sigh...why not check the plugs for burn color?


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## wide_mk1 (Aug 13, 2007)

...doing it tomorrow morning


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## Dave926 (Mar 30, 2005)

I doubt that the cis pump is an issue, they flow pretty well when they are in good health. Check the bentley for flow specs. 

My car has cis-e with the less powerful pump, and i think I calculated it good for about 350whp.


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## TIGninja (Mar 21, 2010)

If you have a MAF reading the airflow then the fuel will not be a problem by changing the turbos. The problem is by running more boost to get the power you are also increasing fuel pressure and causing a rich condition from that.


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## Stroked1.8t (Jan 9, 2004)

if the chip doesn't matter then put 30r on a stock program, you will find it doesn't work.


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## son of planrforrobert (Dec 21, 2009)

An inline fuel pump is a must. Also, no to the 4 bar FPR. If the c2 obd1 software is the same as obd2, it is written for the stock FPR


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## rweird (Apr 10, 2004)

Stroked1.8t said:


> if the chip doesn't matter then put 30r on a stock program, you will find it doesn't work.


no ****. the stock chip is for a naturally aspirated vehicle with 19lb? injectors and a 2.5" maf housing.
do some research before you go spewing false information. :thumbup:


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## Stroked1.8t (Jan 9, 2004)

Stroked1.8t said:


> if the chip doesn't matter then put 30r on a stock program, you will find it doesn't work.





rweird said:


> no ****. the stock chip is for a naturally aspirated vehicle with 19lb? injectors and a 2.5" maf housing.
> do some research before you go spewing false information. :thumbup:


spewing false information, are you kidding me? I was trying to prove a point, the chip matters. At what point did I say it would work? If you read my entire post I said it wouldn't work. I have done my fair share of research and have built and tuned my setup, but this isn't about my project. 

There is nothing wrong with his pump, injectors, fpr, wastegate, MBC, sparkplugs. He was not having fuel issues on the larger turbo so going to a smaller turbo he will have enough fuel. The CIS pump is a bad ass pump, period. The FPR he has is fine for forced induction even though it for a NA engine it still has a reference line going to it and it will raise the fuel pressure to keep a 3 bar differential between intake pressure and fuel pressure. The injectors that he has are enough becasue they were enough for a larger turbo. There is nothing wrong with his wastegate or boost controller because it is controlling boost. If he isn't able to get his boost down then he needs to adjust the rod between the wastegate and the actuator to get it lower, if it is an internal gate, if external then it is the same as his old setup and it worked. He was not having problems with his spark plugs before this turbo change, nothing wrong with the plugs or the gap. IT IS A FUEL ISSUE and what controls the fuel, THE CHIP. If the turbo doesn't matter, why do chip tuners sell different chips for different turbo setups? Obviously you haven't done your research and learned what all goes into a tune. Im sure you will come back with some pointless rebutal but it doesn't change anything I have written above.


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## rweird (Apr 10, 2004)

im sorry kind sir i was unaware that c2 sold different chips for different turbos...

https://www.c2motorsports.net/shop/c-21-forced-induction.aspx
whats that line about not needing to pay to retune with every upgrade(or downgrade? in this case)

never said that you said it would work... i was stating that youre a moron for trying to compare the stock chip to a aftermarket fi chip.

how do you know that his setup is working? fuel pumps go bad, fpr go bad, injectors go bad, spark plugs go bad, wastegates go bad, ignition coils go bad, ect.

chips very rarely 'go bad'. if the do more than likely the car wont run. the chip gets its signals from sensors. guess what. they go bad. could be a coolant temp sensor or an air temp sensor. 

but his plug gap should come down alittle.

or that heavier wg spring. 2x the spring is normally the max you can run.:thumbup:


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## Stroked1.8t (Jan 9, 2004)

rweird said:


> im sorry kind sir i was unaware that c2 sold different chips for different turbos...
> 
> https://www.c2motorsports.net/shop/c-21-forced-induction.aspx
> whats that line about not needing to pay to retune with every upgrade(or downgrade? in this case)
> ...


wow, you are unreal. 
I know this guys setup WAS working because he wasn't listing issues with his larger turbo, these problems came about when he installed the smaller turbo.
It wouldn't matter if I said 2+2=4 you would have a problem with it. 
.
Im done with this thread, I don't want to argue with you. I have more then enough knowledge to help the OP fix his car but there is always a guy like you that knows it all and turns the thread into a name calling event.


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## rweird (Apr 10, 2004)

link works fine for me. try clicking on it instead of copying and pasting. if you have enough knowledge to help him then do it. telling him he needs a new chip is not helpful.

perhaps telling him to check for boost leaks(caused by installing a new turbo and not tightening something enough) because metered air escaping at 15+psi could be causing his car to run rich. that might? maybe? be helpful

relax dooder. just back up your 'knowledge' with some actual facts, because so far you've done nothing but 'spew false information'.


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## wide_mk1 (Aug 13, 2007)

wow, this thread has been busy while i was away...haha

i got my wide-band today and i am going to put it in on saturday...see where i am at

i had a loose fitting on the line connection from the "t" fitting to the wastegate port, tightened that up, but it still spikes 18psi and holds 15psi, which is ok but when it spikes i get a very high pitched squeek, like pressurized air escaping a very small opening (think air brakes on a semi but much more high pitched), which goes away after the pressure settles at 15psi.

I am going to try loosening the thread on the wastegate arm so it opens sooner so i can get the low pressure setting around 10-12psi.

I also checked the plugs. Like an Oreo, black on the outside, white in the middle. I am going to confirm a lean running condition Saturday with the wide-band and look into other possible solutions.

Despite the anger, thanks for the help, to everyone, hopefully ill get this resolved sooner than later:beer:

**on a separate note the car doesn't "break up" under boost anymore (since i tightened that pressure fitting)**


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## wide_mk1 (Aug 13, 2007)

i just put in the aem wideband...powered it up...

at idle the needle was pinned lean...hovering around 17.0-17.8....not good

a few stabs at the gas brought the needle back down to around 12-15, but at idle it went back to the 17 region...

1) does the "quality" of the 12v power source have anything to do with the reading? (i have it running from a 12 power that is also running my boost and tach)

2) does sensor placement have anything to do with the reading? the exhaust is an open side-exit and the sensor is just after the point where the downpipe bends under the car...the bung is at about a 70 degree angle facing downward (as per the instructions)


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## wide_mk1 (Aug 13, 2007)

Bump


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## Daskoupe (Oct 9, 2006)

i had a similar issue.Ended up being a coil.
give the aem its own source.
Let me see your bay


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## wide_mk1 (Aug 13, 2007)

http://klutchonline.com/blog/candy-apple-bunny-robcusick

ill get more "bay specific" shots this afternoon...

ill also give the wide-band its own power asap


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## B4S (Apr 16, 2003)

As well, ground that sensor at the battery. It needs the best ground point you can give it.


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## my2000APB (Jun 3, 2007)

rweird said:


> tighten up the plug gap alittle. .024
> i also have a innovate xd-16 gauge and lc1 wideband for sale. lmk


still wanna sell the afr kit?


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## wide_mk1 (Aug 13, 2007)

so the AEM is grounded to battery and has 12v from a beefy power right off the fuse panel.

coldstart the car idled around 15ish then creeped down to around 13 and then after about a minute climbed back to around 16-17.5ish.

after the car warmed up i drove it around a bit. WOT at 15psi the gauge read about 10.5-10. Partial crusing throttle was around 14.8-15.4.

Are these numbers accecptable?


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## B4S (Apr 16, 2003)

IMO, it's rich up top, but I'd imagine that's the way the chip is programmed. The part throttle cruise is spot on, that means the O2 is doing it's job perfectly :thumbup:.

I'd say as long as it idles fine, even lean, then it's all good to go.


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## wide_mk1 (Aug 13, 2007)

it is lean during a cold start idle

after driving it it idles around 15-15.8

i am pretty happy with it, i was just waiting for someone to say "THAT IS THE WORST, YOUR MOTOR IS GOING TO MELT!!!"...i am gonna go beat it up now:beer:


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## Daskoupe (Oct 9, 2006)

Look for a after maf leak for the lean idle condition


Turn up the boost!or get a t3/t4. 10.5 is super rich
11.2 are perfect


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