Low RPM Bucking/Sputtering Under Load

[sho'noff]

maybe there is water in the fuel tank, heet works pretty well. just don't get it on your hands. also you can check for fuel pressure there is a tire valve thing at the fuel rail, just don't get any on you.

 

[Brook24v]

I decided to minimize the fault codes, so I replaced the o2 sensors (since I had two o2 faults) and cleared codes. After driving for 10 minutes I came up with these:

542: Fuel pump secondary circuit fault
136: HEGO (H02S) sensor fault, always lean

Why would I still have an o2 code???? And what is causing a fuel pump secondary circuit fault?

Then I threw a fuel gauge on it yesterday real quick. I didn't test without vacuum, but with vacuum running to the regulator I was seeing 31-32 PSI at idle and a 35-38 on a WOT blip depending on rather or not it sputters on the hit. I'm assuming 30-45 is idle spec and engine off is 37-43. I was really hoping it was the pump so I can end this headache. I'll test more later.

 

[rubydist]

542 is set when the engine stalls. you can ignore this with no issues.

136 is complaining that the lh or front bank is always lean. since you changed the o2 sensor it is reasonable to assume that it really is lean all the time. this could be due to a vacuum leak on the front side of the intake asm, or due to one or more bad fuel injectors.

I would have the injectors cleaned - if you have the ability to do this yourself you can save some money, otherwise take it to a reputable shop and have them run the cleaner through the injectors. injectors that are not providing the proper amount of fuel could be a cause for the other symptoms you have described.

 

[Brook24v]

Huh. Seems fair enough. I'll dig into these injectors after doing some more fuel pressure testing tonight. Thanks.

 

[sho'noff]

think with your dipstick it could be the valves need to be adjusted. from what I understand they would be the same shims as a kz1000.:duel:

 

[sho'noff]

it may be something simple, if you look at the ignition switch it may have something in the metal contact parts. I have run into graphite lock lubricant in an ignition switch electrical before.

 

[BlooDSMeaR]

I had same issues. Wound up being melted motor harness wires and connectors that sat on top of the rear exhaust manifold. The bracket was not reinstalled correctly and the wires slumped down onto the exhaust manifold.

 

[Brook24v]

Crap, I didn't even think about checking that. I can envision exactly how that could happen too. I'll check it this weekend.

I never did find what's wrong with the stupid car. Seems to run worse when it's 100% cold, but the car can be driven down the road with no signs as long as you don't put it in a heavy low RPM load.

 

[Brook24v]

Also, current codes are showing:

211 - Profile ignition pickup (PIP) circuit fault
176 - Fault/always lean; Insufficient TP change during no oxygen sensor switch detected
176 - HEGO (H02S) sensor fault/always lean

 

[SHO87]

Did you ever get this fixed? I am having the same issues exact to a t. I was thinking it is the ect but I replaced coilpack and wires and made a big difference for the good but I am running a catless y and thinking that could be my problem now but I had same codes prior to swapping the y pipe I have still have same codes but I have changed and swapped out everything you have and I am at the same point you are or were lol.

 

[intimdatr]

I think it ended up being crank cancer?

 

[SHO87]

oh I dont think that is my problem since the motor has had the 60k and the 100k maintenance and it has been acting up for awhile. the car has a 3.2 swap and I am thinking that the stock computer for the 3.0 may be reading its too lean, but because it is being dumped a little more fuel with the 3.2...? the search continues, I am going to switch the ect tonight and see if that helps.

 

[SHO87]

Also could the not switching between the o2 sensors be linked to a bad pcm?