Help! 1997 Subaru engine problems in my 1983 Vanagon

[Jbwhite]

Hello. Just began our adventure across the US in our 1983 vanagon. She has a 1997 Subaru Legacy 2.5L engine. When we hit Georgia coming from the Cleveland area, we started to have some problems. The engine falls completely on its face when I push down on the gas. We have talked to multiple mechanics and have tried everything. We can get it up to 60 mph on the free way as long as I barely touch the pedal. Additionally, fuel mileage has went down drastically. When we get to about 3000 rpm it sounds like the throttle body is being flooded with fuel. Let the gas pedal off, and it starts to go, kinda.

Thank God for manual shift.

We have tried:

New spark plugs
New coil
New throttle positioning sensor
New fuel pump
Cleaned mass airflow sensor
Fixed vaccum leak that was found by break booster
Cleaned throttle body
Ran a can of seafoam
Unplugged the O2 sensors

Looking for some advice!!

[thebigben]

when you cleaned the throttle body, did you take a look at the IACV?

do you have an OBDII reader?
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Ben

'85 2WD Westy w/ Peloquin TBD + 2.2 Subi (Kurt Vannegut)

[jordauto]

Have you scanned the ECM for fault codes. That should the be first step to diagnosing your problem. It sounds like a possible failed MAF sensor not reading the amount of air entering the intake. Another possibility is that the CAT converter could be plugged causing excessive back pressure. The engine will function ok under light load, but when you step on the gas there is too much exhaust trying to flow through the restriction and the engine bogs down, making lots of noise and little power. A shop should be able to easily perform an exhaust back pressure test through the pre CAT O2S hole.

[djkeev]

I know little more than nothing about Subaru but I'll agree that it sounds like excessive back pressure from a clogged exhaust.

Unbolt the convertor, it will be noisy as all get out but does it have power again?

Dave
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Stop Dead Photo Links how to post photos

Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[MarkWard]

An engine needs more fuel to run at 70 mph than say 40. What is the age of the fuel filter and fuel pump? Can you hear the pump running? A fuel pressure test and volume test would be an affordable place to start eliminating the problem.
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☮️

[space]

sounds like a dirty fuel filter
or
Maybe failing/failed fuel injectors
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82 westy
w:
2.5 JDM Subie
Rear discs

[skills@eurocarsplus]

ho-lee-shit

lets stop playing parts darts and throwing stuff at this. lets start to diagnose rather than empty the bank account.

FWIW if you bought an aftermarket coil, get it out of there now. i have yet to see one NOT introduce more problems than it solved.

what are your trouble codes?

running a OBD2 (or any) subaru without o2 feedback is suicide. the ecu defaults to a fail safe mode and runs like epic shit.

lets start with some codes please
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[Jbwhite]

I did run an OBD2 and it lead me to the vaccume leak and the throttle positioning sensor. I fixed both of these problems, and nothing changed. Going to run another test here shortly.

We are also going to look into the IACV. Unfamiliar with that.

Catalilac converter has been gutted, and exhausts have been checked for clogs.

Problem with acceleration still.

[skills@eurocarsplus]

when you replaced the TPS did you set it properly?

it's not just screw it on and go. it must be set within a specific voltage range. failure to do so will lead to crap performance
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[wesitarz]

Fuel pressure test?

[valvecovergasket]