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Old 03-05-2005, 01:58 PM   #1
mavrick
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Default UTEC + Perrin Rails = massive over fuel ? HELP

Well Guys I have a host of problem on my set up and I wonder if any of you can lend a hand?
Set up
Greddy t-67 kit
Xx tunning header/up pipe
Perrin fuel rails w/mod injectors
TGV deletes
1 step colder the right ones
TXS RFL-ti
FMIC
UTEC

All of these problems started after installation of the perrin rails and home made TGV deletes. Upon start up it takes a couple of cranks to get her fired up when she is going I see some white smoke and fuel coming out of the exhaust and it sounds like its running on 3 cyl, backfiring and popping . I did a compression test recently and all 4 were with 4-5 psi at 118ish. I get miss fire codes. My first thought is that I have a bad coil and this is causing un-burnt fuel to leak out the exhaust or the perrin rails are dumping so much more fuel that I canít burn it all leading to the miss fires and the backfiring.

Any thought on this issue would be greatly appreciated.
Unfortunately I have no wide band access at this time. Should I go ahead and pony up the 370ish for new coil on plug wires (4 of them) or do I have other issues.
Thanks
Mav
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Last edited by mavrick; 03-07-2005 at 09:13 AM.
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Old 03-05-2005, 02:27 PM   #2
cdvma
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Does it do this after its warmed up? Can you rev it at all? Did you check to make sure all the wires are pluged into the coils?
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Old 03-05-2005, 02:45 PM   #3
HonduHunter
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i ran perrin rails on a cobb 2.5 map. no problems. its gotta be soemthing else. who tuned your car?
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Old 03-05-2005, 03:05 PM   #4
mavrick
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The car will rev and run it just pops and backfires like it's running on 3 (i am kittyless but this is not that kinda popping). After it warms up the white smoke dissipates but backfire remains. There is still a little splatter and the exhaust smells strongly of fuel. The car has yet to be tuned for the current set up I am just trying to get a drivable tune to head to the closest dyno 3 hrs away.

mav
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Old 03-05-2005, 10:53 PM   #5
x99percent
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Sounds like someone needs to put the U in UTEC.

Do you have access to an OBD2 scanner? Do you have a friend with Deltadash?
Use *something* that gives you the ability to read the ECU's fuel trims, so that you can make adjustments to the UTEC and get your car running properly.
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Old 03-06-2005, 07:49 AM   #6
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I figured it was a user problem but I just did not think changing fuel rail would make my car un drivable. so lets say I have $500 ready to spend what should it be used for? Wideband? New coil on plug thingy? Or tow it to the dyno?
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Old 03-06-2005, 09:42 AM   #7
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Well, I'll ask the obvious question first.... you did change your UTEC injector scaling for the larger injectors, right?
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Old 03-06-2005, 10:54 AM   #8
mavrick
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yes I started with the scaling at 800 and went up to 850 with a minor improvement last night (stock set at 440) still runs like crap. i am at a loss should I spend the money for a delta dash or a wideband or both i have about 500 to spend i need to get this car running right so i can tune it.
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Old 03-06-2005, 12:12 PM   #9
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If you are going to tune it, spend that money on a wideband and an OBD2 reader. Otherwise just spend that (or less than that) on the dyno tune.
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Old 03-06-2005, 01:50 PM   #10
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Well, "tuning" it yourself without a wideband is pretty risky at best. You may be able to get it close, but you'll never get it right.

However, the problem you are describing sounds like a little more than a tuning issue to me. It's hard to say without seeing it, but with your UTEC set like that, it should run. Rich, but it should run. Yours sounds like it's way too rich.

Did you modify the injectors yourself? I have seen people do it and modify them too much and have problems similar to those you are describing.
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Old 03-06-2005, 01:52 PM   #11
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but right now i don't even think i could drive it to a dyno. i would have to rent a trailer and all that mess. i think i will just go with a deltadash and a lm-1 and start from there. now I just need to find that software that allows you to combine the lm-1 and UTEC logs.
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Old 03-06-2005, 01:59 PM   #12
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I had deadbolt mod them for me. But what gets me is none of these problems started until I installed the rails. I have triple checked all the vacuum lines I used new gaskets. Itís just PIG rich right now and I am pulling out my hair trying to figure out what to do. I plan on pulling the plugs cleaning them and do another comp. test to see were I am at I just wish I knew of a way to test the coil on plugs so I could figure out which one if any are bad.
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Old 03-06-2005, 02:02 PM   #13
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also on a side note.. my EGT gauge suddenly went to crap, can a massive over fuel kill the sensor? I have pulled it and every thing seems fine but who knows.
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Old 03-06-2005, 02:17 PM   #14
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Well, running that rich, I imagine your EGT's would be very low. I haven't heard of excess fuel ruining an EGT sensor, but I guess it's possible.

Did you check things like the throttle cable? I assume you took your intake off to install the rails.

Do you have a stock set of injectors laying around you can put in? Obviously you wouldn't want to drive it with them in there, but that would at least eliminate that problem.

Oh, and here's a link to a program that combines LM-1 and UTEC logs. I haven't used it, but supposedly it works. http://mpsav.com/MPSUTECLogger/MPS_U...r_Download.htm
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Old 03-06-2005, 03:07 PM   #15
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I don't have any stocks as there modded now. My car is a drive bye wire but I can check and make sure everything is connected again. also I have heard of people cleaning that sensor on the top of the throttle body to help things out what do you think?
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Old 03-06-2005, 07:32 PM   #16
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Quote:
Originally Posted by mavrick
yes I started with the scaling at 800 and went up to 850 with a minor improvement last night (stock set at 440) still runs like crap. i am at a loss should I spend the money for a delta dash or a wideband or both i have about 500 to spend i need to get this car running right so i can tune it.
Mav
Why you have 440cc stock setting is beyond me. 550cc is usually the correct stock setting.

FWIW
800cc scaling for the injectors and 550cc stock give perfect ST fuel trims at least on my car and TurboXS shop car using the stock MAF tube.
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Old 03-06-2005, 08:50 PM   #17
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There is some type of volume change with the addition of rails and it has to be tuned for. I think??? I swore I read it somewhere??

Plus you can actually raise egts to an unsafe level on a really over rich setup be careful. Over lean and well over rich will both raise egts to unsfe levels. I was climbing well past 1600 on a way to fat rich tune on top end pulls.
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Old 03-07-2005, 08:19 AM   #18
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Quote:
Originally Posted by Wombat North
Why you have 440cc stock setting is beyond me. 550cc is usually the correct stock setting.

FWIW
800cc scaling for the injectors and 550cc stock give perfect ST fuel trims at least on my car and TurboXS shop car using the stock MAF tube.
Ahh. I didn't even notice he had an STi. The 440 setting is for the regular WRX. That could be part of your problem right there.
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Old 03-07-2005, 09:14 AM   #19
mavrick
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I'll go give that a shot and see if that helps out any. on the egt question at idle my gauge just pegs around way past 12000c now I hope there is no this is a correct reading but who knows. The MAF tube I am using came with the Greddy kit and if I am not mistaken is 3.25 ID and the car ran fine before the installation of the fuel rails. I am just pulling my hair out trying to figure out whatís going on here.
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Old 03-07-2005, 09:28 AM   #20
Cosmo
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I wouldn't be too worried about the EGT's right now. I'd worry about the excessively rich situation first. Once you get your AFR right, if your EGT's still aren't right, then worry about it. Doesn't matter what your EGT's are if your car doesn't run.
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Old 03-07-2005, 11:03 AM   #21
mavrick
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well now I am going to try the 550 and if that doesnít work I am going to pull the plugs clean and inspect them do another comp test and if none of that works back on go the stock rails and well see what that does I wonder if any one can chime in on their injector scaling with perrin rail and an STI to give me a ball park. But I have scored a used delta dash for a good price and now looking for a Lm-1 to use
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Old 03-07-2005, 11:18 AM   #22
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Injector scaling should be pretty straight forward. Your stock injectors are 550cc. So, for stock you put 550. Then, whatever the flow rate of your new injectors is will go in the other value.
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Old 03-07-2005, 11:29 AM   #23
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You don't *have* to put 550 for the stock injector value.

The difference between the two numbers dictates the global MAF adjustment used so that the ECU will provide the proper fueling when it is in control.
The aftermarket injector value dictates the fueling used when the UTEC's OLF is in control.
(Example of this kind of thinking: http://forums.nasioc.com/forums/show...77&postcount=3)

If the car is running rich with 440/800, then 550/800 isn't going to be an improvement.

I still say you need to track down an OBD2 scanner or a copy of DeltaDash to see what the fuel trims are. Until you can see what the ECU is doing, you may as well be blindfolded.
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Old 03-07-2005, 12:02 PM   #24
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No, you don't have to put the actual values in it. I just find it easier to work with the actual numbers, then to be guessing a value and hoping it's close.
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Old 03-07-2005, 03:46 PM   #25
x99percent
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It's not about "guessing", it is about using numbers that *work*... numbers that provide nice fuel-trims and get you very close to proper WOT fueling. That way, the UTEC fuel map needs as little work as possible.

See the link in my previous post for an example.
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