SHO is slow....

[AutoSHO]

Well, my thoughts were confirmed today. My car is slower than dirt. Here's the kicker: It gets better once it has been run WOT a few times. What it feels like is a lean condition in the last 20% of throttle opening. The car basically falls on its face past 3/4 throttle.

So far I know: MAF clean, 60K done on time, IAB Clean, Fuel Pressure Good.

What I don't know: Why, even if the car is fully warmed up, I have to run it hard a few times before it figures out how to properly make power. And even then, it still doesnt make the power it should. The problem is worse when it gets warmer, and diminishes somewhat in very very cold weather.

Help!

 

[shojuan]

How new is your TPS (throttle position sensor)?

 

[BlackOnBlackATX]

also you should clean the filaments on your MAF, i was dating a girl who had a similiar problem on her tempo and her MAF was in need of replacement. or also try unplugging it and take a short trip up the street to see if it makes a difference.

 

[Dr.Evil]

an injector(s) may be cloged, causing it to not allow the right amount of fuel. Maybe this is why you need to run it to WOT a few times to blast some of the gunk out of them and then it runs better until it clogs up again. Check your injectors and your fuel filter.

 

[FOSHO94]

I had close to this same problem, change out your MAF, that cured my car. either that or the TPS.

 

[AutoSHO]

FOSHO94:
I had close to this same problem, change out your MAF, that cured my car. either that or the TPS.

One of my previous cars did this as well, and that cured it. I'll try a new MAF Electronics package on top, and pick up a TPS tomorrow. I sure hope its that simple. Thanks for all your help! I'll keep you posted!

*walks out to change the MAF Electronics*

Oh, and if anyone's interested:
Run @4800 Feet ASL
16.65 @ 87.4
16.70 @ 86.6

See why I'm ******? Thats only a very high 15 sec slip at Sea Level. ARGHHH!!!!

 

[DavidT]

also, did you try resetting the computer?

 

[AutoSHO]

dkautumna:
also, did you try resetting the computer?

Yup.

No codes either.

 

[PROPHET]

Could it be clogged cats?

 

[sdpatt]

1. Clogged cats (PROPHET was here first. This looks to be prime suspect).
2. Plugged fuel filter (pressure was good, but flow may be limited).

 

[slickn56]

I was having similar problems before my fuel pumped failed on me. It would do what you are describing right after i would get off the highway. Then after ten minutes of city driving the car would just idle like crap and not be able to pick up rpms. After filling the tank with gas and waiting 10 minutes the problem went away. After it did this a couple of times I replaced the fuel pump and all was good.

 

[AutoSHO]

Well, I unplugged the MAF and drove around today. That appears to be the problem. The car runs fine (aside from the lag, which I assume is from the car only using the TPS) and doesn't fall on its face at a certain throttle opening. I guess its only $160 for the 75mm Pro-Flow MAF, so it looks like my car will be normal (again) in two weeks when I get paid again. In the meantime, I don't know whether to leave the MAF plugged in or leave it unplugged. It runs fine below 1/2 throttle, above there I open it slowly and invariably it will feel like someone turns off the power switch. I believe whats happening is the MAF is leaning out the mixture at high throttle openings, and then the car pings, so the Knock Sensor tells the computer to pull out the timing. Ah well, at least it should be a relatively easy fix.

Oddly enough, both my White SHO's have had to get new MAFs in order to run right at some point or another.

 

[BlackOnBlackATX]

clean the filaments on your MAF, take the electronics package off and spray them down with carb cleaner. theres a procedure for this on shotimes.com if you need it. but dont drive around with it unplugged, if im correct it could cause you to run lean or rich, and you dont really want either (someone else back me up or smack me down on this one). cleaning it may solve your problem anyway and you wont have to get a new MAF.

and since i suggested the MAF first i will take the liberty of saying:

score one for BlackOnBlack! beer

sorry, i had to do that....

 

[AutoSHO]

AutoSHO:
So far I know: MAF clean,

BlackOnBlackATX:

and since i suggested the MAF first i will take the liberty of saying:

score one for BlackOnBlack! beer

sorry, i had to do that....

Heh, I think thats negative points. thumbs_u

 

[BlackOnBlackATX]

also try unplugging it and take a short trip up the street to see if it makes a difference.

BAH! no negative points here, if anything we play like the special olympics, we all win