Problems when giving it gas

[Warren]

So I have 2 new motor mounts and still having this weird jerking with the car.

If I drive with the accelerator pressed down only 1/4 of the way the engine drive smooth, but if I push it down more than that the engine starts to make a sound like it starts sputtering and I lose power and the car starts jerking forward and back. If I take my foot off the gas and then push it down again it will run fine. So I cant really push the gas pedal down to take off or I wont get the power it should be. I am getting no codes at all. When Im on the highway I can floor it and it takes forerver to get from 55 to 80 in 5th gear even when it isnt sputtering or whatever.

So When I let the clutch out I have to take it easy and slowly accelerate cause if I just press the gas down harder it takes a while to get up to normal speed.

Any ideas? Air filter is new, spark plugs and wires have maybe 40k miles on them as well as the fuel filter. MTX Fluid has recently been changed. Using Premium gas only.

 

[rubydist]

what are the codes?


your symptoms are typical of a bad tps, but there are other possibilities which is why you always need to read the codes FIRST.

 

[Warren]

There were no codes, I said that in the original post, but I did just go run a test again just to double check and during KOEO i got 565 but thats cause the clip on the plug is broken so the plug keeps sliding off of the little canister so I zip tied it on just now. I guess TPS it is. shouldnt the TPS throw a code?

 

[SHOtimer]

Not always.

Doug

 

[rubydist]

no, that is the problem with obd1, sensors that are sick but not dead will generally not set any codes, so you still have to guess. Given all that, I would start with a tps.

 

[Warren]

Thanks, Im going to run to advanced auto today and scoop one up and see what happens!

 

[Warren]

changed out TPS, made no difference at all, still have hesitation and stuttering sputtering. Sparkplugs had a little white fuzzy looking stuff on them but on the actual center pin and electrode it was not white ofr fuzzy but dark black. car was running lean for a few days last month but it was corrected by cleaning O2 sensor contacts on plug.

 

[intimdatr]

Dying fuel pump or pressure reg?

 

[Dirk37]

Try resetting the ECU by disconnecting the battery for a minute or so, the lean condition may have messed up the adaptive fueling. When did these symptoms start?

 

[Warren]

Try resetting the ECU by disconnecting the battery for a minute or so, the lean condition may have messed up the adaptive fueling. When did these symptoms start?

I m not sure but think it started happening when the coolant from the leaking hose that goes from the engine to the heater core on the firewall started leaking and corroding the connector on the rear O2 sensor. It started running lean. I fixed the leaky hard/soft heater hose and cleaned the corroded O2 sensor connector with rubbing alcohol and a rough awl against the pins and connectors. Ill try unplugging the battery again to reset the ECU. I picked up a new fuel filter today Ill put it in tomorrow when I wake up and see if that helps.

Someone said dying fuel pump or pressure regulator. Where is this regulator located?

 

[Dirk37]

The regulator is the circular thing with the vacuum hose attached to it next to the blue wire



If you want to test fuel pressure, grab a fuel pressure gauge from one of the auto parts stores, then on the opposite side of the engine there's a test valve that's just like the one used for filling up tires that it hooks on to. The specs are:
KOEO = 30-45 psi
KOER = 28-33 psi

Something else you can try is disconnecting the O2 sensors and going for a cruise, it may be that that connector is so far gone it's making the ECU freak out. The car won't run great at low RPM's and loads with them disconnected but it should be drive able and tell you if that's the problem or not.

 

[rubydist]

ok, now unplug the mafs and take it for a drive to see if that changes any of the symptoms.

 

[Warren]

Unplugged the MAF, it drove exactly the same. Im guessing the MAF is shot? is there a way to fix it or clean it? I have a multimeter, not sure if I can test it with that. This farking thing has these stupid security screws on it with the little metal post in the middle so you have to by a special screw driver to unscrew the damned thing

 

[Dirk37]

You can try cleaning it by removing the sensor and carefully spraying some non-residue electronics cleaner on the two wires. Ace Harware has a bit set for around $20 with the right driver, or a pair of really small vice grips will work.

 

[rubydist]

so if it runs the same with the mafs unplugged, then you can normally rule out the mafs as being the problem.

next I would measure fuel pressure at the rails, like Dirk suggested above. let us know what you find there.

 

[Warren]

Fuel pressure using the schrader valve on the fuel rail says 34 PSI KOEO 30 PSI KEOR. Im frickin stumped here.

 

[Dirk37]

It probably wouldn't hurt to try cleaning your plugs, also make sure they are torqued down all the way, but don't overtorque them. I had a similar issue where under high load the car would fumble around, and after a week of searching I found two of my spark plugs had mysteriously loosened themselves and were leaking. The torque spec is 7-15 ft-lb.

 

[SHOdded]

Was the corroded connector on the engine harness side or on the O2 sensor side? Might be worth replacing the connector and/or the sensor. Check for continuity. You could have an intermittent short there.

Don't know if this will help, but maybe pull the SPOUT connector to fix the timing? See how the car reacts to that.

 

[Mr Anonymous]

Check your intake ground, and verify that the two intake crossover bolts are installed and that the two lower screws for the DIS module are installed as well.

 

[rubydist]

I'm starting to think that one of the following is sick: dis, coil, pcm.

I would disconnect battery, unplug pcm and clean connector, then reconnect and test drive the car. I would also check the stuff suggested in the 2 posts above.