LS1GTO Forums banner

1 - 2 of 2 Posts

1 Posts
Discussion Starter #1
New to this group!
here’s the scoop ..
I bought my husband an 04 GTO for our anniversary ran great! He had joined the military I have since brought the car from Idaho to Virginia ..

the injectors were leaking I did the o rings and since the I drove it maybe twice. so I’m not sure if this was a problem since I’ve done the rings on the injectors are not as this was his car to build I didn’t want to mess with it.

how ever now we have it in his hands driving it seems like the Car is not getting any power pressing the gas it bogs out and hesitates like it’s going to die and has zero power.

things we have done so far

MAS replaced
TPS replaced
All new spark plugs
New O2 sensors
Cats are NOT clogged
Crank sensor
Temperature sensor
Fuel system cleaner

We just ordered new injectors today they won’t be here until Tuesday and he’s going on a deployment for a bit so the car will sit but while it sits I wanted to get some others input. We are all out of ideas on what the hell would be causing this it ran great the only change that I did before it went into his hands was did the rings on the injector previous to that two of them were damn near spitting fuel out of them and it still ran great so I can’t hardly understand why fixing that would cause the car to run like crap all the sudden

Please help!

Worthless reject member
41,096 Posts
Well, if you can get your hands on a scantool, i would look at the fuel trims (LTFT and STFT) and the misfire counters if it supports it. I would check the fuel pressure. I would take note of the MAF reading at idle, should be at least 6-8 g/s. I would check the MAP at idle to make sure it is reading correctly, if the car has the stock cam it should be around 3-4 psi, or maybe 20-21 inHg, whichever it reads. Get the coil packs tested. Also, if you disconnected the coil packs and removed the harness for any reason, it's easy to plug them all back in backwards. it will make your car run like crap. Also, the MAF can be put in (as well as plugged in, if forced) backwards, which will also make in run poorly. You can check each individual injector to see if it is at least working by putting a small screwdriver or stetho on each to listen for the solenoid clicking. You mentioned replacing the temperature sensors, make sure they are reading correctly. the engine coolant temperature sensor on the passenger side head makes a big difference with fueling calculations, and can make the engine run poorly if it is off by a lot. the intake temperature sensor matters as well, but not as much as the ECT sensor. You also mentioned changing the crank sensor, might want to perform a CASE relearn, although you likely are fine without it. Might also want to verify that the cam sensor is OK.

that's about all i can think of for now.

To clarify, "MAS" is the mass air flow, or manifold air pressure sensor? which temperature sensor, the intake air temperature sensor, or engine coolant temperature sensor?
1 - 2 of 2 Posts