Budget LS Guy

Finally got my Fairmont ready to tune and on the dyno we cant figure out why it wont make power. My tuner says there is some kind of restriction but i cant think of any. He also says the VE table is acting backwards. Once it hits like 3500 rpms it bogs down with tons of fuel. We unhooked the charge pipe and we still cant make power on even an NA tune. Its like its itting a wall. Im just going to post a video so you guys can see what its doing. Please help i need boost!


NA Tune

forcd ind

iTrader: (7)

Without knowing much about it, is the air filter on, maybe a rest.
Where is the 02 sensor, maybe an air leak and sucking air, making it
look like a false lean?
Is there maybe a rev limiter in place set low?

aknovaman

iTrader: (7)

Turn the COT and all cat settings back on.

Budget LS Guy

Here are some more details. We took the air filter off and had the same problem still. I was thinking about relocating the grounds because i have them all in one spot behind the intake. Also i am considering that it might be a timing issue, like the cam is off a tooth since i built the motor. I am kind of at a loss. but ever since ive had it running when it is floored it goes ultra rich and bogs down. It should be leaning out if im not mistaken. The o2 sensors are turned off in the tune, and there is no rev limiter

dburt86

iTrader: (2)

stock ecu?

aknovaman

iTrader: (7)

is there some valid reason not to have the 02 sensors turned on ?

Forcefed86

iTrader: (4)

Hard to say without more details. I'd check the mechanical side of it first. Then you'd know it was most likely a tune/ecu issue at least.

Do a compression test and see what the motor is spitting out. If you missed a tooth it will be very obvious. Healthy 5.3 with mild cam usually spit out 150-190.

Also may try putting a peak/hold cheapie tire gauge on the hotside. See if you have any big restrictions pre turbo. (collapsed flex section or something). Have to setup it up with some coils in it pre gauge/sensor like so...

Budget LS Guy

Yes it is a stock ecu. I did some things today and the car seems to be running better. At least from revving it in place. I cant move it because my other car is blocking it. I pulled the intake off and found a vacuum hose not hooked up behind the intake. Not the big one but a little port underneath the big vacuum port. I also relocated the grounds, and moved my wiring harness above the intake because i had a lot of it ran underneath the intake. Not sure yet if any of this really made a difference but the car seemed way healthier.

Budget LS Guy

Did a compression test on my motor and im getting around 210 psi across all cylinders. Does this mean my timing is good? The car is still bogging down when driving it under load. Starting to think it is my pcm or maybe injectors.

aknovaman

iTrader: (7)

It means valves,are sealing well and not burned. Check your pm.

SethU

If your O2 is off, what makes you think it's rich? Smell fuel? Plug readings?

Cylinders not firing will smell rich, but an O2 will read lean.

Are your plugs and wires in good shape? Gapped correctly? Coils have a good ground and appropriate gauge + and - wire? Dwell settings good? All connections/splices completely solid?

Really hard to give feedback with so little info to work with...

You don't have a huge cam on stock springs... do you?

A complete rundown on your build would be very helpful. Otherwise we're shooting in the dark.

All the best

Budget LS Guy

Can you post me the links to your jaguar build and the pickup? Thanks

Forcefed86

iTrader: (4)

Cam may be advanced a few degrees (which is fine). 210 is pretty high assuming the gauge you used is correct. Should be very snappy at those levels. Just watch plugs and be careful with detonation.

Sounds like settings in the MS/Tune are off.

Budget LS Guy

What should i gap the plugs to?

Forcefed86

iTrader: (4)

.025 or so is a good starting point.

Budget LS Guy

Well we worked on it all day and still didn't find the problem. We changed intakes and found the fuel pump check valve was not working. We attempted to swap injectors but the gto one's were too short. We put a couple different tune files in and fixed a fuel trim issue. The problem still existed. I am going to pull the turbo off just as a last resort and see if there is some kind of restriction. Also change the fuel pump.

Bad Apache

Did you get to check for collapsed flex sections/restrictions in the exhaust yet?

Budget LS Guy

I'm about to check that out next.

Moter

iTrader: (20)

are knock sensors turned on?

aknovaman

iTrader: (7)

Yes, they are. We loaded a 2nd pcm with a 2 bar os, and imported factory f body file and massaged settings for the 2bar map in SD and 60b Injectors. Removed intake elbow and it still went pig rich upon mediun accel. We are testing a few things on it this week.