Fuel Management Issues

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Tbly89
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Fuel Management Issues

Post by Tbly89 »

So I just recently bought a 94 Subaru Legacy SS off a guy that put alot of time and money into it. From what I understand it has a EJ22T with a TD04 turbo. I have been stressing about how to figure out this fuel issue I am having when I start the car after its been sitting for a while. It starts fine but as soon as I hit the throttle it cuts out and almost stalls (Feels like not enough fuel is getting to the engine). I called up the guy and he said that its normal on a 94 with a bigger turbo because you cant upgrade the ECU..? Also at around 3000 to 4000 RPM while building boost full throttle it hesitates a bit.

So I guess I need to Figure out how to get more fuel to the engine? Maybe a WRX fuel pump would help??

Has anyone else had this problem?? What can I do to feed more fuel to the engine to balance everything out with out breaking anything???

94 Subaru Legacy SS, EJ22T, TD04, 3" Turbo Back, Custom Intake, Stock ECU, and Fuel System.


NOTE: after it warms up it works fine but it takes 5 to 10 min.


Thanks a bunch my fellow sube friends!
Last edited by Tbly89 on Thu Jul 03, 2014 2:34 am, edited 1 time in total.
James614
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Re: Fuel Management Issues..?

Post by James614 »

We need to know exactly what mods are on there. Did he try to alter the fuel system in any way? Injectors?

With a TD04 alone you should not be running into issues on the stock fuel system unless you're trying to boost beyond the stock fuel cut.
93 Touring Wagon (EJ20G 5spd Swap) -- Finally back and running strong as ever!

05 Outback 2.5XT 5spd -- Now the wife can have her SUV and get in on the turbo Legacy goodness at the same time.
Tbly89
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Re: Fuel Management Issues

Post by Tbly89 »

Right now the car is running at 7 psi... and no....... the fuel system is bone stock.
Last edited by Tbly89 on Sat Jul 19, 2014 8:08 am, edited 1 time in total.
robertpaige
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Re: Fuel Management Issues

Post by robertpaige »

You don't have fuel issues because the turbo. I have a TD05 16g and a FMIC at 12psi and I have the stock ECU with no problems. Unless he threw some big injectors in. You should take some pics of your engine bay, and the fuel rails and such.

Change the fuel filter, check fuel pressure at the pump, check your spark plugs and wires.. that should all help with hesitation.
Had more Legacy's than I know what to do with...
Current: 92' SS
Tbly89
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Re: Fuel Management Issues

Post by Tbly89 »

Thanks a bunch guys. This is my first turbo charged subaru. I need all the help I can get!
robertpaige
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Re: Fuel Management Issues

Post by robertpaige »

This is the place to be!
Had more Legacy's than I know what to do with...
Current: 92' SS
robertpaige
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Engine Running Way Too Lean! What can I do to fix this????

Post by robertpaige »

How do you know it's lean? Is a wideband telling you this? You shouldn't be, but if you are in fact lean then there is a reason for this. Trying to shove more fuel with a manual regulator will not work.

Sounds like other issues to me. Any codes?


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Had more Legacy's than I know what to do with...
Current: 92' SS
rallyak
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Re: Engine Running Way Too Lean! What can I do to fix this??

Post by rallyak »

Just a stab in the dark, if it fine when it's warm how is your coolant sensor? If its not working right it could be running lean when you start it up.
Charles

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Legacy777
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Re: Fuel Management Issues

Post by Legacy777 »

Welcome to the BBS.

Is your car a manual or automatic?

I think your problem is related to how the engine is being fueled. This could be caused by a sensor issue, possibly a coolant temp sensor or MAF sensor.

I had a similar issue on my 90 Legacy. It would only happen first thing in the morning if I didn't let the engine warm up a little bit. It was less noticeable or non-existent when the engine was warmed up. I had other issues I was tracking down that turned out to be a bad MAF sensor. After replacing the MAF sensor my cold start up issues went away.

I would suggest maybe cleaning the MAF sensor with MAF cleaner and see if that makes a difference.

Also, I merged your two threads and am going to move this to the engine forum.
Josh

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1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Tbly89
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Re: Fuel Management Issues?

Post by Tbly89 »

Josh buddy thanks man........everybody thank you and its a manual trans. EJ22T with a TD04 turbo swapped from a 03 WRX. A friend of mine thinks I should get the Apexi SAFC and get it a tune up at a local sube tuner shop. Im willing to try anything at this point. The car ran like shit this morning. Its going to be parked till I figure out this spitting/sputtering bull-crap. It seems its getting worse. I tried unplugging the MAF just to see if it would run better, but it didn't, SO Im gonna go get some cleaner, and the coolant sensor looks easy enough to do. It does run really hot but not overheating hot.

thanks again
Legacy777
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Re: Fuel Management Issues

Post by Legacy777 »

Yeah, if it's running hot, I would check to see if the fans are coming on. If they are not, then yes the coolant temp sensor may be the issue since that temp input directly relates to fueling and whether the fans come on or not.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Mister Anderson
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Re: Fuel Management Issues

Post by Mister Anderson »

What's your location?
91 black SS 5 speed.... 300k on engine.
93 silver TW 5 speed... Track car project
73 kazen red VW bus riviera camper
Tbly89
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Re: Fuel Management Issues

Post by Tbly89 »

UPDATE: I have cleaned the MAF sensor, checked the coolant temp sensor with my multimeter (it works great). My fans work fine, I think it runs hot cus is pretty much 90 degrees here everyday, and its an old car. The turbo could use a heat shield, and I am going to order an aftermarket radiator prob next summer.

So....Engine temp. set aside, I really want to get to the bottom of this fuel issue! The guy that I bought the car from swears that the ECU(EJ22T) is not sending enough fuel because its set for the VF11 not the TD04. After some research online I have found that a bunch of people do the TD04 swap, and have no issues with fuel injection on the stock EJ22T ECU.

So this guy is telling me I should go buy a Apexi SAFC mod, and take it to get tuned. What do you guys think of this idea?????

To be perfectly honest I have been driving the car for about a month now and I think the fuel pump needs to be changed, or swapped for an aftermarket pump that's a little stronger. Also the fuel gauge fluctuates, and does't read correctly, which tell me its old and warn out.

What do you guys think? Also I forgot to mention, It is a gas hog and get terrible gas mileage! Kinda expected coming from an NA engine, but not this bad.

Thanks for all the help!
94 Subaru Legacy SS NA EJ22T, TD04, Turbo back 3" exhaust, Top mount innercooler.
wtdash
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Re: Fuel Management Issues

Post by wtdash »

Hi,
I'd still change your CTS - they wear out.....I know the multimeter told you otherwise.

Why do you say it's running hot? On my car, and all previous Subies I've had, the temp needle sits just under 1/2. NEVER moves past this, and it's been 95+ here the last week (yeah, even in N. ID).

Edit: A new OEM (ONLY!) thermostat might help, too.

The Apexi isn't the answer...keep reading on here. If the PO is telling you to do this, I'd stop listening to him.

Yes, the fuel pump could be causing issues, it's likely original. Get a cheap used STi pump and install kit or just get a Walbro or DeatschWerks 255.

The fuel PUMP is separate from the fuel GAUGE - the fuel sender/sensors on these cars do also wear out - search about that, too.

The gas MPG should be teens around town and low 20's on the highway - really depends on how you drive it!

I'd also make sure you don't have any boost / vacuum leaks. Common on these older cars and w/those that were upgraded.

GL,
Td
Turbo Subies:
'87 GL-10 Turbo - SOLD
'90 BJ EJ22T/DOHC & 5speed swap - SOLD
'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
'93 Legacy SS - 5-speed, SOLD :-(
'02 WRX -SOLD
'96 BD-turbo'd-SOLD
'98 SF - NA-T
Tbly89
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Re: Fuel Management Issues

Post by Tbly89 »

Yeah I didnt think the apexi was a good idea...What im trying to get from this car is reliability, with a little extra boost. Makes for a fun daily driver. I will get right on the CTS, and I think im going to go with a walbro fuel pump. The temp gauge is fine too. It sits at half and never moves. I was worried that it wasnt reading right, and this being my first turbo charged subaru I had to get familiar with how hot the turbo gets.

As fair as the vacuum lines go, Im pretty sure there half assed put together. Im going to be studying hard online to figure out the right way to run the lines. Ill take all the help I can get!!

Also Im going to rebuild the intake because there's quite a few leaks and just put together shitty! I plain on running a snorkel threw the fender as well.

I dont know what the previous owner was trying to accomplish, but he threw this car together as lazy as possible! That being said for the price I paid its a great project! Even with the problems it has right now pushing only 7 psi it still hauls ass up hill. Ive been fixing stupid mistakes since I got it.

Anyway bare with me boys. The biggest reason I bought this car was to learn, and I love Subaru's.

Thanks for the feed back! Keep it coming!
Legacy777
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Re: Fuel Management Issues

Post by Legacy777 »

Have you checked your mpg? If not, I'd suggest doing that. I think the CTS and fuel pump are good first steps as they are wear items, so even if they don't 100% solve your problems they shouldn't need to be replaced until years down the road.

This page will help with the vacuum line routing and yes work on the intake leaks...that will contribute to poor mileage/running.

http://www.surrealmirage.com/vrg3/vacuum/
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Tbly89
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Re: Fuel Management Issues

Post by Tbly89 »

I think I got a hold of my problems...let me try and explain. SO Ive done some reading, and talked to a couple professionals and even had the mechanic at my work take a look at the legacy.

Turns out the engine is running hot because of my air/fuel ratio. The car is running lean, and the reason that it has a ruff time running off the cold start, is there is not enough fuel getting to the cylinders until the fuel pressure rises. I am hoping my new fuel pump will be the answer.

Its got to be either, A: "My fuel pump is too weak" or B: "My ECU is not sending enough fuel"

Is there anyone out there that swapped the VF11 to the TD04 that added anything to the fuel system or ECU??????

The combustion chambers are getting real hot! Im worried im going to blow the thing up!!

Maybe some better fuel injectors would be a good idea too....
Tbly89
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Re: Fuel Management Issues

Post by Tbly89 »

It might be my fuel pressure regulator. I will be taking a look at that as well!
Legacy777
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Re: Fuel Management Issues

Post by Legacy777 »

The first thing I would do is put a gauge on the fuel line going to the engine to verify your pressure. You can pull the vacuum line off the regulator see if the pressure goes up.

The fuel pump is a far more common failure item than the regulator. I honestly don't know if I've heard of a regulator failing. Upgrading the pump to a Walbro is cheap and good insurance for future modifications as well. I'd suggest starting with that.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
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