car running pretty lean, stock setup

[t4-teg]

I just got the car together, and got the WB installed, and the car is running pretty damn lean. When the car is fully warmed up with 93 octane gas the AF gets as high at 14.5:1 in boost (10psi). It usually stays around 13.4ish:1 fully boost, which is still pretty lean.

My setup is ported 2g mani, ported 2g o2 housing, 3'' dp, stock 14b, stock IC and piping. I also have the stock intake and MAF. I took the filter off the MAF and it looks pretty damn clean and newish looking. No wires cut, or anything, no BS honeycomb mods, its stock. My autometer gauge(hooked up to FPR vac line) reads 10psi, and creeps slightly in higher gears to around 12-13psi by redline.

The AEM wideband has a brand new sensor, so I know its not that. Im running stock pump, stock rail, injectors, ect.. The fuel is STOCK. I dont have a datalogger, or any way to moniter the engine, except the WB and boost gauge.

Not sure if it has a boost leak, the vac holds very steady at 20 in hg. I would think a boost leak would make it run richer anyway..

Has anyone else had this problem? It got so bad, the tip of plug #3 looked like it was melted slightly, which is NOT good. That scared the shit outta me, so ive been driving around staying completly out of boost for now.

 

[jjgrizz73]

First off, I def. would NOT run the car in boost at a AFR of high 13s in boost should be much lower. I would think about maybe a piggy back to add some more fuel to it and if you want some bigger injectors. The evo injectors you can get cheap and will last you through plenty of mods even a 16g uprgade if you wanted in the future. I wouldnt really expect the car to be running that lean on your setup but trust your wideband thats what its for.

 

[xezerax]

I would get an safc and some injectors before you boost it anymore. Like jjgriz said thats why you have a wideband.

 

[GRAVEDIGGER]

Something doesn't sound right here. With your setup that thing should be running pig rich, just like they do when they're basically stock. (turbo, fuel system, boost levels, etc.) When's the last time you changed your fuel filter.

 

[t4-teg]

You know, I have no idea when the last time it was changed. Ill do that tomorrow if I can find one in stock somewhere. Good idea.

Why the hell would I need a SAFC and bigger injectors on my setup. Its pretty much stock, and from what I remember, you didnt need a SAFC and bigger injectors when you bought these cars off the lot.

I will change the filter tomorrow, thats a good starting point. Lets talk about the stock FPR, are they good from the factory, or do they wear out over time and hold less pressure? Should I look into that also?

 

[GRAVEDIGGER]

Your fpr shouldn't cause you any problems except when you go to a larger fuel pump like a 255lph. It is then that it can become "overrun" and you can have a problem with getting too much fuel and have the cyl. walls become "washed" and can lead to premature ring failure and such. But with your setup, you should be ok and chances are there is nothing wrong with your fpr.

 

[Demon33]

I just got the car together, and got the WB installed, and the car is running pretty damn lean. When the car is fully warmed up with 93 octane gas the AF gets as high at 14.5:1 in boost (10psi). It usually stays around 13.4ish:1 fully boost, which is still pretty lean.

My setup is ported 2g mani, ported 2g o2 housing, 3'' dp, stock 14b, stock IC and piping. I also have the stock intake and MAF. I took the filter off the MAF and it looks pretty damn clean and newish looking. No wires cut, or anything, no BS honeycomb mods, its stock. My autometer gauge(hooked up to FPR vac line) reads 10psi, and creeps slightly in higher gears to around 12-13psi by redline.

The AEM wideband has a brand new sensor, so I know its not that. Im running stock pump, stock rail, injectors, ect.. The fuel is STOCK. I dont have a datalogger, or any way to moniter the engine, except the WB and boost gauge.

Not sure if it has a boost leak, the vac holds very steady at 20 in hg. I would think a boost leak would make it run richer anyway..

Has anyone else had this problem? It got so bad, the tip of plug #3 looked like it was melted slightly, which is NOT good. That scared the shit outta me, so ive been driving around staying completly out of boost for now.

I would check the fuel system as a whole- fuel pump, filter, FPR. The best way to check is with a fuel gauge to verify your base pressure setting. This will tell you immediately if there is a problem. Low fuel pressure can be caused by a weak pump (worn out, damaged or low voltage supply, etc), clogged filter, or bad FPR. With a gauge you can verify that the fuel pressure rises with the vacuum line disconnected from the FPR and lowers when the vacuum line is attached.

 

[Demon33]

Your fpr shouldn't cause you any problems except when you go to a larger fuel pump like a 255lph. It is then that it can become "overrun" and you can have a problem with getting too much fuel and have the cyl. walls become "washed" and can lead to premature ring failure and such. But with your setup, you should be ok and chances are there is nothing wrong with your fpr.

His car is a '90 and is almost 20 years old. If he is still on the original FPR there is a possibility that it could be going bad. A fuel pressure gauge will help you verify this. When troubleshooting, you can't rule anything out until you verify it's functionality and proper operation. FPR aren't high on the list of parts failures, but they can and do fail from time to time. You need to verify this to rule it out as a possibility.

 

[booostedGSX]

+1 on the fuel filter. Plugged filter will inevitably cause a lean condition. Keep us updated.

 

[Demon33]

Something doesn't sound right here. With your setup that thing should be running pig rich, just like they do when they're basically stock. (turbo, fuel system, boost levels, etc.) When's the last time you changed your fuel filter.

I agree, something doesn't sound right here. Boost leaks lead to running rich, but in your case, you're running lean. Have you checked for exhaust leaks before the O2 sensor. Outside air entering the exhaust stream before the O2 sensor could show up as a false lean condition.

 

[Demon33]

I just got the car together, and got the WB installed, and the car is running pretty damn lean. When the car is fully warmed up with 93 octane gas the AF gets as high at 14.5:1 in boost (10psi). It usually stays around 13.4ish:1 fully boost, which is still pretty lean.

I just had another thought. Could you possibly have calibrated the WB incorrectly? Maybe you're not acutally running lean, but the WD is telling you otherwise. Just a thought.

 

[t4-teg]

nah the WB is correct. It was in my boosted integra for years. Its now in the dsm with a new AEM sensor. Theres also no leaks before the o2 sensor. That has been verified.

Ill keep you guys updated as to whats going on with it. Im off work tomorrow, so that will be my day to diagnose the problem.

 

[t4-teg]

Forgot a little bit of info. I did the aircan mod, actually i just removed it, no leaks from the MAS to the turbo though, and I believe that would be the only place that a leak would cause the car to run lean.. Hell its even lean at idle, 16.7ish : 1. I know at idle it can run a little lean and be ok, but im mainly concerned about it running so lean in boost.

Fuel filter will get changed tomorrow, and we will recheck.

Is there a place on these cars to hook a fuel pressure gauge up to to test it? or wil I need to go the aftermarket route and get the whole return line/FPR/gauge?

 

[Demon33]

Forgot a little bit of info. I did the aircan mod, actually i just removed it, no leaks from the MAS to the turbo though, and I believe that would be the only place that a leak would cause the car to run lean.. Hell its even lean at idle, 16.7ish : 1. I know at idle it can run a little lean and be ok, but im mainly concerned about it running so lean in boost.

Fuel filter will get changed tomorrow, and we will recheck.

Is there a place on these cars to hook a fuel pressure gauge up to to test it? or wil I need to go the aftermarket route and get the whole return line/FPR/gauge?

You could use something like this- Fuel Pressure Gauge Set

It mounts your fuel pressure gauge to the top of the fuel filter. I have mine there and it works great for setting and verifying base fuel pressure. However, you cannot see it while driving to verify pressure on boost. You'll need a cab mounted gauge for that.

 

[t4-teg]

^ Ehhh if I were going to get something like that, id just make it, and buy a 0-100psi or even 0-50psi gauge for like $10.

Ill change the filter tomorrow and see if its any better. I guess im going to have to look into a datalogger too pretty soon. can a logger tell me the fuel pressure? Im guessing not, since theres no sensor on the FPR, but idk.

 

[GRAVEDIGGER]

Nope a logger can't tell you fuel pressure. That's what the fuel guage is for, but you knew that already. A logger can tell you all the valuable information though.

 

[Demon33]

^ Ehhh if I were going to get something like that, id just make it, and buy a 0-100psi or even 0-50psi gauge for like $10.

Ill change the filter tomorrow and see if its any better. I guess im going to have to look into a datalogger too pretty soon. can a logger tell me the fuel pressure? Im guessing not, since theres no sensor on the FPR, but idk.

Ya, for sure I'd make one if I had the means. You could probably drill and tap the stock banjo bolt and attach the gauge. I'm not sure exactly whether or not there is enough metal at the top of the stock banjo bolt to old more than 3 threads. Maybe someone with prior experience can chime in.

As far as gauges go, if you want to monitor fuel pressure on boost (in-cab), you'll need a gauge that reads higher than 50 psi. My 1G has a base fuel pressure of between 36-38 psi. With 12 psi of boost that puts the fuel pressure at 48-50 psi. With 15 psi of boost, fuel pressure goes up to 51-53 psi, out of the 50 psi gauge's measurement range. I believe that on 2G cars, the base fuel pressure is 43 psi. So, any boost over 7 psi will be out of the gauge's range. I suggest a 0-100 psi gauge.

 

[toofast82]

your stock air/fuel target on your ecu is as low as 9.3:1 at wot at high load of about 15psi. I believe it is still coded under 10:1 at around 10-12psi
Definitely dont mod the car (bigger injectors) without diagnosing your actual problem. I would look at the fuel system as a whole as the culprit as suggested. Start with the fuel filter because thats always good to do anyways. I would suggest a fuel pump rewire regardless if thats your problem or not. Check for bad fuel pump, faulty regulator, etc

 

[jjgrizz73]

Good information guys, I completly forgot about that stuff because I changed all mine when I put the new motor in. Chances are there is something wrong with the delivery from pump to the rail. If you are running all original parts, its not a bad idea to think about replacing it all with some better parts (if you have the $ of course). An evo pump or 190lph, a rewire, afpr w/ gauge ( i use the megan afpr it was 75$ with gauge ). Like I said trust the WB, and all of this information still means to keep your car out of boost its running way too lean.

 

[GRAVEDIGGER]

Here's a pretty cheap, reliable way to monitor your fuel pressure from Summit Racing. It mounts ontop of the fuel filter and only takes a few minutes to install. I guess if you want to make your own that would be fine too, but by the time you do that it would probably be just as easy to get this or one like it. Just my personal opionion though.


qty.








B&M 46054 $33.88
Estimated Ship Date: Tomorrow




Brand: B&M
Product Line: B&M Analog Fuel Pressure Gauge Sets
Part Type: Fuel Pressure Gauges, Engine Diagnostic
Part Number: BMM-46054
Gauge Type: Fuel pressure
Gauge Range: 0-100 psi
Diameter (in): 1.500 in.
Sweep: Full sweep
Sending Unit: Mechanical
Gauge Face Color: White
Gauge Number Color: Black
Pointer Color: Black
Bezel Color: Black
Liquid Filled: No
Quantity: Sold individually.
Notes: Come with two adapters designed to fit; Acura Integra 1990-2000, Honda Civic/CRX 1988-2000, Mitsubishi Eclipse 1989-2000.

Gauge, Fuel Pressure, 0-100 psi, 1 1/2 in., Analog, Mechanical, Each

Check your fuel pressure.
Maintaining proper fuel pressure at wide-open throttle is critical to preventing lean conditions. These B&M fuel pressure gauges are also great tools for tuning your engine to produce maximum horsepower at all rpm ranges. They're made specifically for each application, for an easy installation.

Back to Search Results

 

[jjgrizz73]

Hmm, well for 40$ more I'd rather have the ability to adjust the fp and read it. Even though with this setup its not really needed everyone upgrades at one time or another. I tried finding the megan racing one I use but Slowboy dropped it. Im sure its around somewhere though.

Edit: heres a link for it- Megan Racing Fuel Pressure Regulator - Fuel Pressure Regulator

 

[t4-teg]

We will see. Im trying to keep the car mainly stock for now. I dont want to re-wire the stock pump just to get my AF a little richer, nor do I want an AFPR. Its a stock car guys, theres obviously a problem with the fuel delivery, which im looking into. Before I start modding, you better believe the car will be running 100% perfect. Thats just how I am, fix the problems before you start modding.

On a side note, when I do start looking for an AFPR/gauge Ill come back to this thread, because it does have some good info on that.

Thanks for all the suggestions so far guys, im off to try to find a fuel filter now.

 

[GRAVEDIGGER]

I checked out this link:
Edit: heres a link for it- Megan Racing Fuel Pressure Regulator - Fuel Pressure Regulator
It looks like a good deal, but I noticed that it says it is NOT a rising rate regulator (1:1)
But, I did a quick search and found this: http://www.dsmtuners.com/forums/bolt-tech/275686-megan-racing-fpr.html?highlight=rising+rate+fpr

I can't decide what to make of it. It sounds like nobody can verify whether or not it IS a rising rate regulator. I only go by what it says and that is it is NOT. Buuuut, then you have others that say they have run it with XX amount of boost with no issues. So, IDK.

 

[jjgrizz73]

I run it with 23psi on a evoIII 16g with a walbro 255 and 680cc injectors and it works fine for me never had a problem with it.

 

[t4-teg]

OK fuel filter changed, as well as thermostat(just because I had one) and the AF ratio is still the same. full boost around 14:1. At idle its about 17:1.

Not sure where to go from here, I guess next will be changing out the FPR with a known good one, just to eliminate that, mainly because its the next easiest thing to do. After that, I guess it will be a pump change if needed.