SS refuses to accelerate, fees like it misfires too?

[monkeyposeur]

Sorry for the long post. This has been a nagging problem for as long as I have owned the SS w/4EAT & 163k. I will fix one thing, the problem will seem to go away for a little bit, and then come back. I'm getting desperate and may just take it to the Subaru Dealership to see if they can diagnose it, although I am not confident that they will be able to figure it out.

The car is extremely sluggish off the line. Sometimes it will refuse to go over 15-20 mph for a few blocks, and then maybe start to get up to speed. It doesn't matter if I press the gas pedal gently, or floor it. Then when it finally starts to speed up it feels like there is some misfire or explosion coming from the engine. The car will buck a bit as well.

At first I thought it was the transmission, but I found a bunch of cracked vacuum lines and intake pipes. I have replaced the air intake from the TB to the turbo, the turbo inlet pipe, all of the PCV lines, and all of the vacuum lines. Recently I found a split in the turbo inlet elbow, which was dissapointing since it was brand new and extremely hard to find. Some epoxy fixed it and in the meantime I had a custom turbo inlet elbow/coffee can fabbed up which I will install shortly.

Head gaskets are new. All seals have been replaced. New plugs/wires (NGK V-Powers gapped at 1.1). I'm thinking about gapping them at .7 but idk.

I would find a cracked intake or vacuum line, replace it and the problem would seem to go away for a day and come back. I would replace another line, seem a little better, then come back. I'm losing my patience.

No CELS. I hear the turbo spooling up, but no acceleration happens.

What could be causing this? Bad MAF? A leak in the intake manifold gaskets or exhaust mani? They shouldn't leak as they are new and installed to specs. A bad solenoid? Should I try a MBC? I guess it could be a lot of things. I would rather not just throw a million parts at this of course. I'm just hoping I can narrow it down.

I don't think it is the fuel pump, since it starts up just fine and never dies. It just seems like something is holding the car back. TIA.

[cj91legss]

Start with a fuel pump, sounds like that may be the problem honestly. Have you also replaced your fuel filter? How new are your plug wires? Have you ran a check on your coil pack/ignitor?

[SiCkSTi04]

Have you tried unplugging each spark plug to see if the idle changes with each unplug. An ohms test on each injector would also be a good idea. This will determine if you have a bad injector.

[wtdash]

Not what you want to hear, but I still think you have a vac leak. If @ alll possible, get a 'smoke test' done.

Call around - I'd bet a lift ticket to Alta there's a performance/dyno shop that can do it.

You can also build a plug for the intake pipe w/a valve and apply compress air to look/listen for leaks. Don't use a lot of pressure....<10psi should be enough - READ UP on it, though.

When it runs between fixes, is it running great? Or just slightly better?


I'd also double-check your timing belt. Since I don't know your level of expertise, don't take it personal, but the crank marker (use the back mark, not the front arrow) is sometimes messed up.

Td

[monkeyposeur]

Start with a fuel pump, sounds like that may be the problem honestly. Have you also replaced your fuel filter? How new are your plug wires? Have you ran a check on your coil pack/ignitor?

I ordered a Wallbro Gss341 w/install kit. I should get it in a few days. That would be great if that is what the problem is although I will be pleasantly surprised if it fixes the issue. Even if it doesn't fix the issue I wouldn't mind upgrading anyway as I am planning some basic mods in the near future. The plug wires are new, have about 2k on them, and good quality. The fuel filter isn't too old, although I am going to replace it as well. It was out of stock when I went to the parts store yesterday so I didn't get a chance to replace it. I haven't checked the coil pack. I have the Subaru FSM so I will read up on how to check it.

Have you tried unplugging each spark plug to see if the idle changes with each unplug. An ohms test on each injector would also be a good idea. This will determine if you have a bad injector.

I haven't done this. The car idles fine. When I rebuilt the engine upon the first start up a plug wire was loose so I know what the engine feels like when a plug is loose. I'm open to trying this. What will it tell me? I am assuming I have to remove the injector to ohm test it. I'll read up the procedure in the FSM. My reluctance to remove the injectors is due to the fact that I hear they can be a bit hard to remove. I have a spare 22T intake mani with injectors that I can rob for replacements.

Not what you want to hear, but I still think you have a vac leak. If @ alll possible, get a 'smoke test' done.

Call around - I'd bet a lift ticket to Alta there's a performance/dyno shop that can do it.

You can also build a plug for the intake pipe w/a valve and apply compress air to look/listen for leaks. Don't use a lot of pressure....<10psi should be enough - READ UP on it, though.

When it runs between fixes, is it running great? Or just slightly better?

I'd also double-check your timing belt. Since I don't know your level of expertise, don't take it personal, but the crank marker (use the back mark, not the front arrow) is sometimes messed up.

If it is just another vac leak then I would be thrilled to know about it. I'll call around about getting a smoke test done. I would rather get a smoke test than applying compressed air since I don't have an air compressor.

When it runs between fixes if usually just runs slightly better for a day or two, usually less. I think that I have been chasing multiple problems all at the same time which makes diagnoses more complex.

I've done a few timing belt replacements and follow the FSM procedures and use the correct marks, never the arrows. I used a Gates timing belt kit, counted the teeth, used the correct marks, triple checked it, etc., so I am confident that I installed it properly. However, there is always the possibility that I got it a tooth or two off or jumped. I'm not an expert grease monkey by any means, but I love working on my own vehicles ever since I decided that I couldn't afford to go to a mechanic unless I absolutely have to. Replacing the HGs and all the other seals on the SS taught me a lot.

I also noticed that you are from N. Idaho. My mom lives near Priest River and is looking for a 4EAT for her '92 NA BC if you know of any. Wish I could help her out but she is a bit far away.

Thanks for the suggestions everyone and I'll update as I go along or have any other questions. Anyone else feel free to chime in.

[wtdash]

PM on Trans info.

You can test the injectors w/out removing. Key off, remove the injector connector, and test across the 2 pins. Should be 11-13 - double-check against the FSM or on here.

Td

[SiCkSTi04]

^^Exactly

[martimus919]

You can buy a Pressure Leak Test tool from siliconeintakes.com. The plates come with a schrader valve so you could just use a bike pump with it.

Here's a link to the Testers:

http://www.siliconeintakes.com/index.ph ... 9ffbc1ca8b

[monkeyposeur]

I made some progress today.

I replaced the fuel filter and took the SS for a quick spin. Acceleration is greatly improved. However, the misfiring comes back like before when I quickly increase the throttle. But not as bad as before. In fact, if I gently increase the throttle I don't get the misfiring. This leads me to believe that the fuel pump is indeed going bad. The Walbro I ordered should arrive sometime next week and I am extremely hopeful that my problem will be fixed after installation!

I then checked the ignition coil. The primary coils registered 1.0-1.2 ohms (FSM spec 1/0.7 ohms). Secondary coils registered 14.2-14.5 ohms (FSM spec 13.8 ohms). It appears that the ignition coil is within tolerances and is good.

I tested the injectors as well. They ranged from 12.5-14 ohms (FSM spec 11/12 ohms). What are the tolerances for replacing the injectors? As I stated above, I have a set of spare injectors that I could inspect and possibly use. I may just get the spares flow tested and swap them in later.

Thanks for the link martimus 919! I'll have to check it out. How do you use it? Pump up the system and see how much pressure it can hold? What numbers would I look for. It looks like a great tool to have.

[cj91legss]

Probably just pump it up to 10psi and leave it alone for a bit and see if pressure drops

Sent from my SGH-T989 using Tapatalk 2

[Legacy777]

The injectors may be a little bit worn, but they are probably still ok. If you have other injectors that are more in spec you could use them, but removing the injectors is a pain in the butt.

[martimus919]

Probably just pump it up to 10psi and leave it alone for a bit and see if pressure drops

I would do this also, you can also check for any leak noises.

[monkeyposeur]

I tested my spare set of injectors that were on my spare intake mani and they all registered 11.6 ohms. I was able to get them out fairly easily following this guide posted by WitchHunter Performance: http://www.witchhunter.com/subieremoval1.php4 The best tip given is to twist the injectors and use a flat head screwdriver to pop them off.

Removing the injectors from the SS was a little tricky, but I was able to get all of them out and the replacements installed in about an hour and ten minutes. To install the driver's side I had to remove the wiper fluid reservoir and I removed the air intake on the passenger side for installation of the other two injectors. Note: I wasn't very careful in removing the original injectors since I had replacements and I destroyed one of them. Also, the lower rubber o-ring on two of the injectors stuck in the intake mani; one broke in half and I had to dig the other out with a seal picker.

The performance noticeably increased. Under hard acceleration I got a misfire or two, but if accelerated easy I wouldn't get any misfires. This leads me to believe that the original injectors would have still functioned, but not as well as the replacements.

Hopefully the Walbro will arrive tomorrow so I can install it. I would love to solve this problem so I can move forward with some light mods (TD04 & XT TMIC).

Question: What could cause all four injectors to get so far from specs? Would a bad fuel pump, filter, using 85 octane gas wreck the injectors?

[Legacy777]

The injectors are essentially an electrical coil. Over time and cycles the electrical windings in the coil will age and cause the resistance to increase.

[monkeyposeur]

I installed the walbro. Acceleration is dramatically improved. But the misfire feel will still happen under hard acceleration. If I ease up on the gas it doesn't happen. But if I gas it too hard it put-puts. You can really feel it in you feet when it occurs.

I took a low quality video with my phone in case any one wants to get a better idea of what it sounds like. It sounds like a thumping in the video. Sorry the video sucks. I'll take another one tomorrow and see if I can do better. Video: http://www.youtube.com/watch?v=HtWzyBAi ... e=youtu.be

Well, I guess I need to get a smoke test or get a pressure leak tester and see if i have a vacuum leak somewhere.

Could it be leaking exhaust mani gaskets? The put put phenomenon feels like an explosion and is coming from the bottom of the engine. When I dismantled the engine there were some exhaust studs that stripped. I bought a thread kit and installed new threads. I'll get the heat shields off tomorrow and see how it looks.

Any other ideas? I'd love to solve this problem.

Another question. How will the pressure tester allow me to actually pressurize the system? Wouldn't any pressure I put in there just go out the airbox? I just want to understand how it works. edit: Nevermind. I did some research and realized that the pressure tester will cap off the inlet elbow.

[turbo970]

what octane rating you running

[monkeyposeur]

Always Premium. 91 octane here in Salt Lake City.

[turbo970]

try a bottle of heet could be a lil bit of water in the fuellines

[Legacy777]

I don't hear anything in the video. What time does it occur?

Also, why are you running around with the hold button on?

[monkeyposeur]

I wasn't able to complete my boost leak tester as I spent a bit of time gathering up the parts. If it works I'll post up a few pics of it. Hopefully I'll be able to check for boost leaks tomorrow.

Sorry for the extremely poor video I posted above. I uploaded a slightly better one. It's the best I can do with the equipment I have. The misfiring/explosion begins around 0:15 into the video that I posted on youtube: http://www.youtube.com/watch?v=6j2yB4sE ... e=youtu.be It's hard to hear.

Josh, I had the car with the hold button because I was driving it in 'Manual' mode. Sometimes if I have it in 'D' it is very slow so sometimes I will hold it in '2' for quicker acceleration.

Although the coil pack is within 95% of FSM tolerances (approximately 5% above specs) should I consider replacing it? I looked in the FSM parts catalog and the part no. is listed as 22433 AA360. I found one on rock auto starting at $76. There are separate listings for autos (which I have) and 5MT. Are they interchangeable?

On a good note I drove the car all around town today and it did quite well if I was careful in how I applied the gas. It still likes to be quite slow upon initial start up, but perks up once it warms up. It will hesistate around 20 mph, but if I slightly let up on the gas and then apply pressure to the pedal it starts to accelerate again.

Thanks for all the help and suggestions everyone.

[SiCkSTi04]

Did you gap your spark plugs?? The correct spark plug spec is as followed - NGK V-Powers, part no. BKR6E11 Gap: .044

Edit: I saw your first post again, they are set to 1.1mm (.044in)

[Legacy777]

The AT coils are Hitachi brand coils, while the MT coils are Diamond coils. Get the diamond coil. They are interchangable.

What were your readings on the coil and what were the specs in the FSM?

[cj91legss]

It still likes to be quite slow upon initial start up.

That's most likely because the car doesn't want you to boost until it's around the correct operating temperature

[monkeyposeur]

The AT coils are Hitachi brand coils, while the MT coils are Diamond coils. Get the diamond coil. They are interchangable.

What were your readings on the coil and what were the specs in the FSM?

Primary coils; 1&2 - 1.2 ohms, 2&3 - 1.0 ohms (FSM spec 0.7-1 ohms).
Secondary coils; 1&2 14.5 ohms, 3&4 14.2 ohms (FSM spec 13.8 ohms).
I'll go to the junkyard and get a Diamond coil pack as soon as I can.

It still likes to be quite slow upon initial start up.

That's most likely because the car doesn't want you to boost until it's around the correct operating temperature

I figured it was something like that. Thanks.

[Legacy777]

Those readings are "close" but that may just be an indicator the coil is wearing out.