View Full Version : Need help diagnosing problem (video)
spankle my wankle
10-06-2010, 08:30 PM
I was driving to cincy when my car started losing power. I had no throttle response, could barely make it up hills, and the car would sputter under heavy throttle. No check engine light came on and none flashed would I grounded the connector. I've checked the following:
TPS (in range)
AFM (all values in spec)
Fuel Pressure (stayed around 35-40psi)
Spark on all plugs
I checked for vacuum leaks and found none
I even created a gasket "block off plate" for the acv to make sure it wasnt leaking
Now when i give it any gas or WOT i can't get it to go above 2000rpms. I've attached a video for helping diagnose this. Cost me $500 to tow back home so I'm pissed and ready to blow it up. The only thought I have now is either throttle body or clogged cat. Honestly I have no idea though. Thanks for the help.
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FC Zach
10-06-2010, 10:58 PM
I feel your pain brother, I'm dealing with the same BS on my car and want to blow mine up as well (anyone have a Barrett M107 available?!) You have checked all the things I would have recommend to. OMP? Is there a possibility that the AFM is bad and still checks out well with a meter? I have an extra AFM I just need to see if it is a S5. Did you check the TPS with a DVOM or did you just use the two light method? If not, do it with a DVOM and check for smooth movement across the throttle range.
djmtsu
10-07-2010, 06:48 AM
Have you checked for fuel yet? I know you put in a new pump, but what about the filter?
My $200 offer stands!
jerd_hambone
10-07-2010, 08:00 AM
FUEL.FILTER!!
Replace.it..My.old.S5.had.the.same.problem.
rx4ur7
10-07-2010, 05:30 PM
Sounds and acts like a blocked exhaust.
misterstyx69
10-08-2010, 10:25 PM
It's an S5..you are in LIMP MODE Dude!
that is what happens when your OMP is either on it's way out or Disconnected.
Check the CODES,,pull em up and see.
FC Zach
10-09-2010, 06:30 AM
^ ^ ^ "No check engine light came on and none flashed would I grounded the connector."
jerd_hambone
10-09-2010, 07:05 AM
Seriously! Get a new fuel filter! Haha
It's cheap and may fix the problem.
Redshft
10-09-2010, 07:11 AM
^ ^ ^ "No check engine light came on and none flashed would I grounded the connector."
Does the check engine light come on ever? I was working on somebody's car once and was thrown off because it wasn't throwing a code.. then I realized the light never came on. Pulled the piece out of the dash and found out the previous owner had pulled out the bulb.
FC Zach
10-09-2010, 10:44 AM
Well that is definitely a problem, he may very well have the same issue.
FerociousP
10-09-2010, 12:36 PM
the light works, fuel filter was changed not long ago....
Redshft
10-09-2010, 12:55 PM
Well, assuming it's not in limp mode then, my next thought would be a clogged cat.
jerd_hambone
10-09-2010, 12:57 PM
the light works, fuel filter was changed not long ago....
Was the strainer changed also?
FerociousP
10-10-2010, 04:24 PM
yep.
NoDOHC
10-12-2010, 12:04 AM
Actually, the clogged cat is a distinct possibility.
I hate to say it, but check compression.
How is your oil pressure?
It could also be a bad connection in the wiring harness.
FerociousP
10-12-2010, 09:05 AM
It was a clogged cat.:willy_nilly:
FC Zach
10-12-2010, 10:11 AM
:party::cheers2::party::hurray::hurray::party::wil ly_nilly::hurray:
Cool, congrats on the diagnosis!
rx4ur7
10-12-2010, 05:43 PM
Afraid I have seen plenty of them. Was the classic description by your write up and video confirmed it.
When you pull it, check to see if there is any substraight left, if not check to make sure the screen mesh is still in the cat. The substraights are wrapped in a stainless screen, many times when the cats clear out completely that screen gets blown out. Usually they will get caught at the exit. Some times they do not and get blown into the silencers. (getting them out can be a challange)
This will also happen with the multiple precats, very common where the screen from one or both of them get into the main cat and block it.
Glad you found it.
djmtsu
10-12-2010, 06:02 PM
Actually....he kinda did it to himself.
Header, RB catback, and a high flow cat.....with the air pump running directly to the cat to pass emissions....and never took it off.
He cooked the cat hardcore.
rx4ur7
10-12-2010, 06:32 PM
Yep, that would do it.
No problem with running the air pump, just need to run the air through some sort of ACV/Diverter valve. We used the Ford diverter, cheap and works. Should maintain a check valve also.
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