Sputtering low end driving

[mapoff]

First of all, thank you for taking YOUR time to help another enthusist.

Problem: When driving under 2k rpms steady the car sputters as if pressing and releasing the pedal rapidly. Kind of a intermit jerky ride. This problem 99% of the time happens with "spout" in. No advance timing, fine 99%

What I've Done: steady fuel pressure, timing 10*btc, new plugs, new wires, new module, maf is good, new tps, new o2 sensors, 93 octane, no codes, rst computer. This is killing me. No one in 5 years and 3 mechanics figured out without me spending $1000. they all want to try a diff computer because its too much to t/s deeper.

New discovery: Disconnected the tps. Check engine light comes on(duh) but does not hesitate. Plug is and it stutters. my tps is at .97 volts at idle. I like doing things right. If i have to unplug it i think that is still going to hurt my mileage which i can't afford. You all are geniuses and i'm hoping someone can save my insanity.

 

[HISSIN50]

the first two things i usually recommend are checking the TPS and plug wires.

how is the range on the TPS? do you have a dead spot between 1-2 volts (or anywhere else)? an analog VOM works well for checking it out.

good luck.

 

[nidyanazo]

Dont run 93 fuel with timing set at 10*btdc. 87 will be just fine. Only go to 91 or 93 when your timing is ~14+* or so... Like Hissin said, your TPS may not be reading properly in the rpm range where you get the "studdering". If it's fine when the tps is disconnected, try another one.

 

[mapoff]

As I mentioned this is a brand new one and its doing the same thing. I was actually wrong about unplugging it. It still does the same thing just less when the tps is unplugged. Problem goes away even more when the "spout" is disconnected and there is no advance in timing. Problem is getting slowly worse and worse. Sounds like a sloppy timing chain to me but i'd hate to think how much money it would cost to have that replaced.