mr spree

iTrader: (4)

When the engine gets warm, at about maybe 70% throttle it feels like it holds back. Hard to explain.

But if the engine is cold there is no problem. Anything i can check?
Thanks for any help

mr spree

iTrader: (4)

Checked for codes and the only code im getting is P0405 for the EGR since i dont have one, but that wouldnt mess anything up would it.

When i stomp on the throttle it falls on its face

BaddBird

iTrader: (6)

check your fuel pressure

mr spree

iTrader: (4)

Its got 60 psi at the rail

BaddBird

iTrader: (6)

This only happens after warm up?

mr spree

iTrader: (4)

yea seems like it, ive gotten on it when i just started it up and it pulled hard, but when its warm from driving around ill stop on it and the power feels to straighten out. It used to straighten out and then pull and then straughten out and then pull

BaddBird

iTrader: (6)

So when the car is cold you have power when its warmed up you don't. Does it rev normal when its warm?

mr spree

iTrader: (4)

^^^thats another thing, ill give just a little gas real fast and it will rev up real slow to about 1500 or 2000 rpm, and then slowly crawl back down to normal idle, sometimes it will stay at 1500 or 2000 rpm.

1quickirocz

may have an o2 sensor issue. Its in open loop (not adjusting fuel trim from o2 data) when its cold and when it warms up it goes into closed loop and reads the sensors. If your o2 sensors are reading incorrectly due to a bad sensor or a wiring issue then it could be leaning it out when you go under a load causing a loss of power.

BaddBird

iTrader: (6)

Do you have cats on the car?

mr spree

iTrader: (4)

I was thinkin that might be the issue too, its in a 92 s10, and the shorty headers have the 02 bungs right after the collectors. Would relocating the 02's make a difference? Where should the 02's be?

What kind of 02's are good ones? They have to be the flat 4 pin ones (female connectors)

mr spree

iTrader: (4)

Yes i have cats on it

BaddBird

iTrader: (6)

Anychance you have a cat stopping up?

BaddBird

iTrader: (6)

I would think with shortys you would be close to the same position as the stock manifolds.

mr spree

iTrader: (4)

If the cat was stopping up wouldnt that be any time i punch it? Even if the motor was cold?

Here is a picture of the Shorty's with collectors and 02 bungs on them, tell me what you guys think

BaddBird

iTrader: (6)

Most of the time when a cat is partially stopped up you will notice a hugh loss in power after the cat heats up. Did this just start? I dont think your 02 location is the problem. Do you have a scanner?

mr spree

iTrader: (4)

Yes i have a scanner, only code it throws is p0405.

How could i check the cats? There brand new too

BaddBird

iTrader: (6)

Has this setup ever ran right? Can you monitor the fuel trims with your scanner?

mr spree

iTrader: (4)

Ive been driving it for about a week now, and its been like this when it gets warm.
No i dont think i can monitor the fuel trims but ill look over the manual for the thing, its an older one my dad has.

BaddBird

iTrader: (6)

Ok you can scratch everything said about the cats. You are going to have to get a hold of a scantool not a coder reader 2 totally different things. You are going to have to monitor what is going on in the pcm.