Dead End, Need Help...

[Jucostud]

Needs some help with my uncles car. He's got an 06 gt with 127500's, mac lt's, prochamber, jlt cai, and steeda cmdp's. car has around 100k on it. Driving home for work the other day, mid trip the car instantly started to run horrible, wouldn't idle, and had no power.

We found that the fuel rail on the drivers side back by the firewall was leaking by the injectors. took the fuel rails off and noticed the pod by the back injector was bent.

We replaced both fuel rails, replaced all the spark plugs, cleaned the injectors and replaced all the o-rings, and cleaned the cai.

Before starting we found that the oil was 3 quarts low. The car idles a little better now, but still surges and drops to 500 and bounces back to 3000. When we tried to drive it, it feels like the whole driveline is shaking directly under the front seats. When the car actually idles properly, everything sounds fine... it doesn't stay that way very long though.

I have no clue what's wrong now. Any help would be much appreciated.

 

[JEWC_Motorsports]

Try spraying some carb cleaner around the inatke manifold. Sounds like a vacuum leak.

 

[Jucostud]

I've had a vacuum leak, and it never made the car shake like this before.

 

[AnotherS197GT]

I'd pull the valve covers.

 

[weather man]

3 quarts is a lot of oil. When did he last check it?

 

[AbdullaGT500]

I've had a vacuum leak, and it never made the car shake like this before.

A vacuum leak could definitely make the car shake if it's bad enough. Is the check engine light on? If so, what code(s) is it throwing?

 

[Jucostud]

check engine light never came on.

 

[GallopingFord]

I've had a bad shake due to a vacuum leak between the manifold gasket. No code was even thrown.

 

[Jucostud]

Ok. I'll check it. It's not just a shake though. The car feels like its trying to take a shit on itself when u try and drive it. I'm just hoping it's not internals. My uncle don't have that kinda money right now.

 

[86GT351]

First thing. Even though there is no check engine light SCAN the car. Might have a PENDING Code in the system. Does sound like a vac leak. Be very careful when spraying the cleaner around the base of the intake.

Have you thoroughly checked to see if there is an oil leak? 3 quarts low is not good. No leak indicates a possible internal issue. Also look into doing a Compression Test

 

[fdjizm]

Hmmm, coil packs OK?

 

[ski]

If the CAI filter was re-oiled after being cleaned, then it may have been over oiled, which can coat the MAF sensor and cause idle and performance problems. Suggest cleaning this sensor.

Also, clean the TB. It's probably real dirty if it's never been cleaned, which can also cause engine running problems.

And check that all of the CAI connections are tight.

Finally, if the battery was disconnected before the engine was worked on, then the ECU has to re-learn the idle strategy, which can cause idle problems. Driving for 20-50 miles should get the idle back to normal. There's also a procedure in the battery maintenance section of the owner's manual that can expedite the re-learning process.

 

[Jucostud]

all of the problems happened before taking the car apart to fix things. we cleaned the cai while it was down. it was able to dry for about a week. everything is installed properly and we've had a couple days to check it over to make sure everything was put back together right. as far as the the ecu and tune goes, the car can't be driven down the street. something is causing the car to run like total shit!

 

[skwerl]

Whenever making any kind of change on my car that affects air or fuel, I've found it helpful to disconnect the battery for 30 seconds before restarting. Then fire it up and let it idle for 2 minutes without AC and 2 minutes with the AC running. This lets the car's adaptive learning strategy relearn the idle immediately instead of trying to make the car run based on the prior configuration.

 

[BruceH]

So it ran fine then one day out of the blue started running crappy, is that correct?

A couple of things come to mind, spark plugs but you changed those, a stuck pcv valve (it's inside the drivers side valve cover), vacuum leak but you checked that, fuel filter. Did the car idle normally before? A cammed car hunting for idle speed is usually tune or tb related.

 

[Makdaddy]

Whenever making any kind of change on my car that affects air or fuel, I've found it helpful to disconnect the battery for 30 seconds before restarting. Then fire it up and let it idle for 2 minutes without AC and 2 minutes with the AC running. This lets the car's adaptive learning strategy relearn the idle immediately instead of trying to make the car run based on the prior configuration.

^^^^

May need to clear it after you fixed the fuel rail problem

 

[psfracer]

Needs some help with my uncles car. He's got an 06 gt with 127500's, mac lt's, prochamber, jlt cai, and steeda cmdp's. car has around 100k on it. Driving home for work the other day, mid trip the car instantly started to run horrible, wouldn't idle, and had no power.

Pull the valve covers. Because it happened "all of the sudden" mid-drive, I am willing to bet its a valvetrain problem. Sounds like a couple of dead cylinders due to a problem with the valvetrain.

 

[irishpwr46]

Check the oil pressure. Sounds like a problem I had with no oil pressure and the vct wouldn't work. Ended up trashing the whole longblock

 

[Jucostud]

Pull the valve covers. Because it happened "all of the sudden" mid-drive, I am willing to bet its a valvetrain problem. Sounds like a couple of dead cylinders due to a problem with the valvetrain.

How do u check for bad valves or cylinders?

 

[05stroker]

How do u check for bad valves or cylinders?

I would pull the covers and make sure all the follower are still in place. The lack of oil could have created slack in the valve train and a follower could have popped out of place. Also seeing the condition of the cams ect. will tell you if there was oil starvation as that is were it usually shows first. Pull those covers and post some pics. That's where I would start with what you have described.