550'S + 2G MAF SAFCII %maxed out

[BIGGSIE]

Ok need some quick help, on my 1G I'm running 550's and a 2G MAF. I have not gotten around to installing my 190 pump yet. When I run 15psi I have to max out the safc on my hi settings (50%) and I'm still knocking. at 10psi i'm @ +33% with 1-3 counts of knock. Here is my question, will the 190 pump help this problem or will I need an AFPR?

 

[DSMtuned]

I think you need to go the other way-- lean things out.

This 2g mas is unhacked, right?

If so, then you have a similar set-up to mine. My highest setting at around 5500 rpms is 15%.

I say you start over from 0% because you could be getting knock from TOO MUCH fuel.

Good luck!

-Craig

 

[CanadianTSi]

WOW you must be waaaay rich, The 550's along with the 2g MAS should almost cancel eachother out. Try turning it down to around 0 and see what happens.

 

[BIGGSIE]

I don't think I'm too rich. My Lo, Med, and Hi trims are good and my o2 reads a little lean if anything. What are your lo settings like? I've got mine at 1K=+14%, 2K=+15%, 2.6K=+15% and gradually up to +20%. Every car is different so it may not be relevant. I would totally agree with you but the car runs good, I assume if it was pig rich it would run like poop. The wierd thing about it is that I thought 1G's could safely run 15-16 psi on stock fuel components. If I have 550's I should be able to run 15-16psi no problem. Anyway, I hope someone can explain this it's got me totally confused

 

[CanadianTSi]

Well my understanding is that the 2g MAF gives roughly a 20% leaner signal and the 550's flow roughly 20% more than the stock 450's, so those two should roughly cancel eachother out. I don't see why you are running so lean???

 

[BIGGSIE]

I thought they would cancell out too. anyone have any ideas as to why I'm so lean? I have no boost leaks, and a brand new fuel filter. My mods are in my profile.

 

[boostnbuds]

Maybe because your afc is set as high as it can go with 550s you could be just maxing out the pump capacity.

 

[BIGGSIE]

Well i'm putting in the 190 pump on saturday so we'll see what happens after that. Also I just realized that I haven't checked voltage to the pump while driving, maybe my stock pump isn't geting enough power. Anyone know if I can get a regulator (or rail) from a different dsm to raise base fuel psi?

 

[kristmen]

Originally posted by BIGGSIE
Well i'm putting in the 190 pump on saturday so we'll see what happens after that. Also I just realized that I haven't checked voltage to the pump while driving, maybe my stock pump isn't geting enough power. Anyone know if I can get a regulator (or rail) from a different dsm to raise base fuel psi?

Someone can correct me if i'm wrong but I thought I read once that the FPR from a non turbo 2.0 DSM was higher then the turbo one.

Can pick one up for like 5 bucks at a junk yard.

 

[hostile]

If your adding that much fuel something is wrong.

Like canadian TSI said your setting are way off. With 550's and a 2g mas you shouldnt be anywhere near +15% fuel.

Actually you should still be leaning it out some because you would still be running fat.

You need to step back... turn down the boost... and run everything at zero settings.

If your still getting knock at low boost you need to check out the mechanical part... maybe you have some carbon buildup on the pistons or something that is increasing the compression and causing knock.

 

[BIGGSIE]

OK I stepped back and set the boost to 10psi and the SAFC to 0% and it knocks like hell. Gradually raised the % to get no knock and ended up with my hi settings at about +20%. If I raise the boost to 15-16psi I need to max out the AFC to get knock to a safe level. I think Hostile may be on to somthing. If I have excessive carbon build up on top of my pistons it will raise my compression. Wouldn't a simple compression test prove that idea? Anyone else have any ideas?

 

[DSMtuned]

Originally posted by BIGGSIE
OK I stepped back and set the boost to 10psi and the SAFC to 0% and it knocks like hell. Gradually raised the % to get no knock and ended up with my hi settings at about +20%. If I raise the boost to 15-16psi I need to max out the AFC to get knock to a safe level. I think Hostile may be on to somthing. If I have excessive carbon build up on top of my pistons it will raise my compression. Wouldn't a simple compression test prove that idea? Anyone else have any ideas?

Mopar combustion chamber cleaner does wonders for taking care of this!!!
http://www.outreach.psu.edu/users/res122/DSM/
http://www.neons.org/howtos/MoparCleaner.shtml

 

[CanadianTSi]

Are you 100% sure that your Injectors actually are 550's???

 

[BIGGSIE]

Um pretty sure, I just ordered them from Extreme PSI.

 

[KeltonDSMer]

It's definately the fuel pump. It makes sense to me. If the FPR raises the pressure according to boost, that is harder for the pump in two ways; it demands more flow in the first place becuase of the incresed airflow and the increase in fuel pressure decreases the flow of the pump.

So, when the motor is needing the most fuel when the boost goes beyond stock, the fuel pump is flowing less than it would be able to at lower pressures.

Try installing the fuel pump and I bet it will be better.

 

[BIGGSIE]

ok I did some diagnosis and decided it's not the fuel pump that is causing my problem. I did a compression test (dry) and came up with some low numbers. 96-94-85-96 So now I think that carbon deposits may be keeping my valves from sealing properly. The only other things I can think of that would cause low compression is bad piston rings or a bad headgasket. Since I'm not losing coolant or having any drivability problems I would say the HG is good. And for the rings, if they were bad my dipstick would pop out due to the excessive blow-by or I would be burning oil. Anyway I'm going to use some top engine cleaner and then do another compression test and see what happens. Does anyone have any input on this? What should my compression test results look like on a 130k 1990 stock 6 bolt?

 

[BIGGSIE]

Just remembred another question, How much does the weather affect our tuning? It has gotten quite warm here in NY the last few days and my trims say I need even more fuel now is that normal?

Thanks for all the help guys,
Biggsie

 

[BIGGSIE]

I realized that I did my compression test (above) when the engine was cold, So today I tested it hot, came up with even lower #'s 91-92-90-91
Then I did it with oil in the cyl's and the results were the same. OK now this means what? I believe that since the #'s did not change between the wet and dry test that the rings are ok. So now I am thinking my problem is in the valves. Anyone have any input???

 

[BIGGSIE]

Well last week I set up an appt. with our BG guy to have a fuel system/ head cleaning done on my car monday. I am hoping that this will fix my problem and I will be able to turn down the SAFC some. I'm thinking if that does not work then I will just get a AFPR and turn up the base psi. Anyone have any input on my question about the weather affecting our tunning? I feel like I'm just talking to myself here someone chime in please!

 

[Bastard1g]

is it really true that A 2gmas and a set of 550's will cancel each other out? I have that combo and have heard that they dont. I cant find the post though.

 

[DSMtuned]

Well last week I set up an appt. with our BG guy to have a fuel system/ head cleaning done on my car monday. I am hoping that this will fix my problem and I will be able to turn down the SAFC some. I'm thinking if that does not work then I will just get a AFPR and turn up the base psi. Anyone have any input on my question about the weather affecting our tunning? I feel like I'm just talking to myself here someone chime in please!

Weather definitely affects our tuning!! I live in Colorado and we can have an 80* day and then snow the next day. That's the only thing that sucks about the SAFC. You constantly have to be tuning, as things like the temperature and barometer affect how much fuel the ECU will dump in. I'm used to haveing the logger plugged in all the time and when I'm about to get on the throttle, I log. I log at least once a day and then adjust as needed. Then I watch the EGTs and FP gauges to verify that everything is cool when I'm not logging.

It takes some time, but you'll figure out what your car likes.

 

[kristmen]

I dont know if you still care or not but I was talking with the owner of DSMChips.com and he mentioned that the stock 5 speed FPR is 36~37psi and the stock auto FPR is 43psi.

If you still care that is.

Also I'm sure this wont be your problem but let me tell you about something I just had happen to me. I upgraded to 550's and put in a new fuel filter and my 1G MAF is HACKED TO SHIT.

Car ran ok it seemed... Drove down the road ok but when I went WOT around 5500~6000 it would KNOCK LIKE HELL. I'm talking like you took a stock DSM and put 25 pounds of boost to it on stock injectors and pump and went WOT... I mean like WHOA.

We tried for 3 days to figure out why. We tried -+ 50%, you name it. We took the car out and logged with the PocketLogger and one thing we noticed was everytime I went WOT just as it started to knock the o2 voltage dropped WAY off...

I would go back out and log and see if your o2's are dropping off just as the knocking starts. Dont try to watch it well you drive but start a log take off WOT and as soon as it knocks let off the gas. Then go home and look at those logs and see what the o2's were like when it started to knock.

If they drop off then you will know for sure if its lean or rich. My guess its its going to show they drop off and its lean as hell.

 

[kpt4321]

1. Get a fuel pump. There's so reason to try to run 550's on the stock 1g fuel pump, it's a bad idea. In fact, the stock fuel pump will usually start to be "not so happy" with stock injectors if you're running decent airflow on pump gas.

2. Once the fuel pump is in, put your hi throttle settings about the same as your low throttle, and tune from there.

3. Check your base timing.

4. DON'T use a FPR with a higher base fuel pressure to fix your problem. If the fuel pump is taking a crap on you, a higher fuel pressure will only make it works. As fuel pressure increases, fuel pump flow capacity decreases.

5. The 2g MAF and 550's don't perfectly cancel each other out, but they do work against each other. Usually you will end up adding a little bit of fuel.