[shanehutton]

So, my car doesn't seem to have any power below 4000rpm. Pulling away from a stop the car is crazy slow. I can't even break the wheels free on snow or wet pavement. Once it gets up to 3500 - 4000 rpm however, the car pulls very hard all the way up to redline.

Possible Symptoms (Could be completely unrelated as well).

-No power below 3500 rpm (Cannot break the tires loose accelerating from a stop) - WAY slower from a stop that my 00 NA was.
-Slow to rev from a stop
-On some cold winter mornings the car has a very poor initial idle and it is VERY hard to get it to rev. Once it hits 2000 rpm it wakes up. - Related???
-Once power does come, it it pulls very strong and has no problem maintaing 17psi
-I was plugging and uplugging stuff to see if anything changed today and after I tried driving with the TPS uplugged I turned the car off and re-plugged it and got the tranny flashing arrow and the car could barely move in Drive - Felt like it was slipping and engine wouldn't rev past 2000 RPM. Reverse was fine and if I put it in Low it seemed fine as well.
-I have about 5psi showing at 2500rpm and can get 17psi at higher revs.
-Idle in Park shows 12psi vacuum (if it matters)

Attempts to fix it

-ETC sensor changed
-Front 02 changed
-MAF cleaned
-IPD HD TCV
-All new vacuum lines
-IPD R.I.P kit
-Cap/Rotor/Wires/Plugs
-REBUILT MY TURBO (It was pretty gummed up and had a lot of carbon buildup so I thought that surely this would fix it.)
-Tightened wastegate actuator
-Loosened wastegate actuator
-clamped actuator so wastegate couldn't open
-Stock and ST ecu have same issue

I am running out of ideas:
-Tranny slipping at lower RPM so ECU is killing power to stop slipping. Higher RPMs are fine so the ecu allows it.
-Crack in exhaust housing killing low speed exhaust flow (can't hear and leak and would I be able to make and hold 17psi if this was the issue?)
-Clogged CAT? (again. wouldn't this affect high RPM power even more???)
-Bad compression (Haven't had a chance to compression test it but it could explain the complete lack of power until the high boost comes in. (still seems weird though).

HELP. I AM LOSING MY MIND.

 

[shanehutton]

Oops. I don't have a sig set up.

1998 S70 T5 SE
Automatic
249,000km

 

[JRL]

Re: Help Me Connect The Dots (shanehutton)

At those miles it could literally be anything or a combination thereof

 

[heavyiron]

Re: Help Me Connect The Dots (JRL)

one thing you don't mention is how long you have owned your car, and if this is a new symptom or one you bought it with. You mention the car is hitting 17psi. T5 motors do not have much power below 2500rpm (especially automatics). Some tunes (like ST) can make this more pronounced since the boost comes on later in those tunes. Need to know more about the history of your car. Especially how it was before you started throwing money at it. Do you know what your air/fuel ratios are running? Is the car getting up to operating temp? If not, your coolant temp sensor could be bad causing you to run rich and have less power down low

When was the last time you changed your fuel filter or checked your fuel line pressure. I don't haave too many ideas to offer b/c it loooks like you have done a good job going over the common stuff. Check compreession and leak down. I was shocked when after my PCV service I blew out my rear cam seals from excessive crankcase pressure. Had the comp. checked and the readings came back between 115-125 with a 25% leakdown loss

on a motor with only 89,000 miles!

Unique situation my oil rings were still good, but my compression rings were bad. That is why I wasn't hardly burning but I was getting excessive crankcase pressure

 

[shanehutton]

JRL - Not sure if you saw but it was in KM. That makes it 154 miles and I was under the impression that wasn't that much.

Heavyiron - I got the car last fall and it was in need of a full Stage 0 so I would say it has never been right.
-This issue is the same with the stock ECU and the ST. The only difference is the top end.
-No idea on the air/fuel > I suspected the car running rich in the winter cold weather start issue.
-I already changed the coolant temp sensor
-Full PCV replacement as well

I am aware that the car won't have a ton of power below 2500rpm but this is really bad. If I pull away from a stop at full throttle in a 90 degree corner in the rain I won't even get a hint off wheelspin until it gets to around 4000 and the engine jumps to life. Then the car is looking for any grip it can get. No joke, my 0-60 is probably about 10sec +

 

[heavyiron]

Re: (shanehutton)

forgot to mention- poor idle could be your IAC (idle air control) these can get clogged and can benefit from a good cleaning with carb cleaner

 

[shanehutton]

Re: (heavyiron)

The idle is very smooth at around 900 rpm. I cleaned out the IAC really well mid winter. The valve moves very freely.

 

[shanehutton]

Re: (shanehutton)

I have 2 ideas in my head right now.

1. Car isn't starting in 1st. Would it do this in Sport mode and not give a CEL or the flashing lights? It would have to have been doing this for months without a CEL.

2. Running really rich and there is just too much fuel to make any power until the really high boost comes in.
-I just got an emissions test though and it passed no problem. If it was running rich enough to cause bad drive-abilty wouldn't it fail the e-test?

 

[LloydDobler]

Since you've already done so much, I'd say it's time to start checking things that are easily overlooked. For example, make sure your CEL isn't burned out by checking it before you start the car.

Does that car have variable cam timing, and could that be malfunctioning? It should throw a CEL if it's busted I think, but you never know.

Also you could go check for codes anyway, and see if the car thinks something is wrong that didn't throw a light. It's free at autozone or some comparable auto parts store I'm sure.

 

[shanehutton]

The light works. It's on now that the car went into limp mode. It hasn't been on continuous though and this problem has been consistent for months.

I can't find anywhere in Canada that reads codes for free. Anyone???

I think I am going to buy a basic code reader tomorrow. I have been holding off looking for a full OB2-Computer set-up that will run on Mac OSX.

It's a 98 so no VVT

The more I sit here and think about this the more I think the car has been starting in 2nd or 3rd gear this whole time. It has lots of power once the revs build and it is very quick on the highway and downshifts/kicks-down and pulls just like it should. It really feels like it would if I was trying to accelerate a manual from a stop in too high a gear.

Modified by shanehutton at 6:40 PM 4-26-2009

Modified by shanehutton at 6:55 PM 4-26-2009

 

[t5mmmm]

Re: Help Me Connect The Dots (shanehutton)

Quote, originally posted by shanehutton »

-Idle in Park shows 12psi vacuum (if it matters)

FWIW, 12 hg of vacuum at idle seems a bit low. Idle vacuum is supposed to be 18 - 22 hg. You may want to recheck your vac lines.

 

[shanehutton]

Yeah, sorry, I think that is way off. I have been too lazy to go back outside and check but I guess I should do that now.

I think it is more like 20 +

 

[heavyiron]

Re: (shanehutton)

If the car is starting in 2nd or third and you do not have winter mode engaged your TCU could be the culprit. If you are running rich and have not gotten a CEL, it is still possible it could be your MAF sensor or you have a vacum leak (even though your replaced the lines) and are getting unmetered air into the system.

 

[shanehutton]

I just checked my vacuum readings.
Engine at operating temp
Idle in park - 16
Idle in drive - 12

Looks like I am still leaking somewhere

 

[LloydDobler]

Sounds like it's time for a smoke test at a local shop. Or, if you have Ace or some other local hardware store, you can buy large rubber plugs to fit into your intercooler tubing and pressure test with those. They're hard enough to drill out and then you can jam fittings into them.

Like this:

 

[shanehutton]

I just looked things over and the check valve on the line between the manifold and the purge valve is flowing air in both directions (took it out and blew through it both ways). I would think that this would cause air from the manifold to get cycled back to the intake pipe. Could that be stealing my low rpm power?

Also, I realized that I haven't changed all my vac lines. I missed the ones on the back of the engine that are going to and from the fuel pressure regulator. A leak down there couldn't be good either. Could a leak down there be causing the car to run rich?

I feel like I am getting closer. Can anyone confirm that the check valve should only flow one way (away from the purge valve???)

 

[LloydDobler]

Often times check valves have a little arrow on them confirming direction of flow.

And yeah, if your fuel pressure regulator isn't regulated, that can definitely cause mixture problems. Worth checking out. The regulator also might be bad, if you pull the vacuum hose and smell fuel in it, I think that's a telltale sign, although to do it right you should test the actual pressure.

 

[volvotool]

Re: (LloydDobler)

Don't you have a trustworthy independent mechanic you can take the car to? There's no way I'd own one of these cars without one.

 

[shanehutton]

No, I just moved to a new city and I typically do all my own repairs. This one just has me completely stumped.