2G Sluggish after half throttle

[JuGs]

Ok i just picked up a gsx. Its real sluggish after half throttle. Did a blt and 2 minor leaks one at the bov and one at biss. Also did a compression test... heres my numbers....dry/with oil...at operating temperature.

1 170/185

2 185/200

3 185/205

4 195/210

Plugs are gapped right. Only thing i have left to test is the tps...fpr and new fuel filter.

 

[chrysler kid]

Modifications ?

If the car is bone stock suspect the blow off valve. The stock one is known to leak.

 

[JuGs]

Completely stock but a 1g bov.


Pcv is good. Only thing i suspect is tps....going to try a new fpr and fuel filter as well

 

[OGDSM1989]

The Factory service manual says that anything over a 14psi differential limit between compression on any cylinders could be a couple issues

1. poor contact between ring a cylinder wall
2. poor valve seating or leaking gasket, valve stem seals etc etc

your cylinder 1 and 4 are way off, just a little info from our local Service manuals ....

 

[JuGs]

Yes i was worried about the compression test being that far off between cylinder 1 and 4. But dont think that would have caused my issue due to the fact its still at average compression/slightly higher compression than average.

 

[VtecvrsTurbo]

Anything after half throttle would indicate to me that you are in boost. Have you performed a boost leak test yet?

 

[DirtyWaterDSM]

Time to break out the spray bottle and liquid soap, I also think its a boost leak.

 

[Black95TSIawd]

Phantom knock. Or real knock. Timing is being pulled.

Cylinder 4 having so much compression tells me that there is already oil in the combustion chamber, or really really bad buildup. 180 should be stock max.

 

[JuGs]

When i picked up the car it did have the cel light on. Checked the codes and 3 came up...cylinder 4 misfire. ..fuel trim bank 1 and tps malfunction. Cleared codes and hasn't came back yet. Ill see if i can locate a camera to look in the cylinder.

 

[JuGs]

So being the compression is a bit high on the car. If I run some seafoam through it that will help. Now what about if I leave the car sit over night with a tablespoon of seafoam in each cylinder? Would/should I suck it out before starting it the next day? Or should it not hydrolock the motor with that little amount in each cylinder

 

[JFPryde]

I agree that it sounds like timing, for one reason or another. If you're running an adjustable CAS you may need to check your base timing.

It takes a good bit of fluid to hydrolock a motor (more than the volume of the cylinder when the piston is at the top of its stroke).

 

[JuGs]

I don't think the 98 cam sensor is adjustable tho? Or am i wrong? I thought only the 6 blot cas was adjustable. I dont think its jumped a tooth...it shouldn't run if it had...or there would be internal damage.

 

[JFPryde]

The stock 98 cas isn't no. I suppose I should have paid attention when you said it was stock. As mentioned before, knock is another reason for timing being pulled. Its possible your running lean due to fuel delivery issues, but that's just another hypothesis. Being able to log would be helpful in this scenario. Your ecu should be compatible with evo scan. Maybe you wanna look into that?

 

[delta448]

Unplug the TPS and measure the sensor itself with an ohmmeter. Should read between 3.5k-6.5k ohms between pin 1 (where the green/yellow wire connects) and pin 4 (black wire connects) - measure the sensor pins, not the wires.

Then between pin 2 (brown/red) and pin 4 (black), and also between pin 2 (brown/red) and pin 1 (green/yellow) - it should change smoothly as the throttle valve is opened/closed (one way increases resistance, the other decreases - you really need an analog meter [one with a needle] to check for smoothness). If this is not smooth (it jumps somewhere), the TPS is faulty and needs replacement.

Then between pin 4 (black) and pin 3 (yellow/red) it should be infinite with throttle open, and under 150 ohms when fully closed (if not under 150 when fully closed it also may be due to mis-adjustment). The manual says 0 ohms but you'll rarely get this in the real world.

Adjusting when the IPS opens (Idle Position Switch - which is pins 3 and 4) is critical (or can lead to high idle or idle surge) and is described per Mitsu manual here: http://www.dsmtuners.com/forums/newbie-forum/255885-bad-tps-again.html#post151940336.

 

[JuGs]

Yes i plan to test the tps today or tomorrow. I did another blt and fixed the biss screw leak. I can hear a leak somewhere else but cant find it feel it and soapy water isnt working. Also noticed a pretty good exhaust leak...I have a feeling thats a good part of my issue.

Ran another compression test after seafoam twice....now with a wet test it reads 195 on all 4 cylinders.



Edit

Also during the boost leak test I would putnit to about 25psi and it would take roughly 20 to 30 seconds to hit 0. If I remember right 1psi a second is good. It would slow down at around 12 psi

 

[JuGs]

Well i found my culprit for my sluggish issue. A fuel injector got stuck so i went to fix it and replace the fuel filter. ...the line going in broke once i touched the filter....was damn near pinched closed....fixed the line and she pulls good now