cpljenkins01

Did not find my problem. It still starts leaning itself out after sitting for more than 15 mins. Just put a o2 sensor and throttle positioning sensor and a coolant temp sensor.

Punchy

Check all your grounds from engine to body and body to the battery neg.
Add more ground jumpers from engine to body if you don't have one already.
Check the EFI relay (maybe swap it with the starter relay) They go soft sometimes from heat soak and don't deliver full voltage.


Was just going through the same problem, But for me its always multiple things going bad at once (Not fail, But not working fully.).


Noticed the O2 gauge was only moving in the lean with the occasional normal swing and stuff like the brakes being depressed and the turn signals make it freak out.
(These are signs of bad grounding because The O2 sensor goes higher voltage during lean and voltage to low to make the jump across a bad ground.)
After finding the bad ground spot (Battery to body)The O2 gauge was swinging higher but not still not full swing, It still plunges hard lean during acceleration for take off and speed up, But goes normal-ish during cruise.
Checked power at the coil and only 8 Volts, Replaced EFI relay and now the O2 gauge swings full, I don't have the slight lope at idle and 12V at the coil (Its a wonder the fuel pump was holding pressure at all) .
The O2 gauge bottoming during acceleration should be ether AFM or the TPS which I haven't checked yet (My money is on the TPS as I have had the same problem years before, Went bad but threw no code).


For you I also suggest checking and reseating fuses AM1 and AM2 (I have seen the AM2 fuse burnt just enough that it looks normal but keep the injectors from getting enough power to keep them open at higher RPM.)

Shady Cadence

Under the dash, above thr drivers kick plate you'll see two ground points, one has white with black tracer lines, the other ones are brown. Disconnect the brown ones, there's two wires to one terminal. Cut the connector off, strip clean wire and crimp a new ground connector on, re-attach to ground and try your truck.

It's cheap, it's easy, and it just might fix it.

cpljenkins01

I will check into the relays. I have upgraded my grounds and I have checked my ground and all them seem clean and good but will double check to be sure. I have flamethrower injectors, hardline del, and egr del. But it hasn't showed any problems all summer. It seem to have started about 4-5 months ago.

vasinvictor

iTrader: (3)

What is the "hardline delete" mod? Do you have a vacuum leak? Spray carb cleaning around common points of leakage. Checked fuel pressure? A failing pump can work intermittently. You did say it works well when cold, so that points to a sensor problem in closed loop. What's your base timing set at? What's the condition of your cap/rotor/plug wires? Got any arcing? Your TPS may well have a dead spot in it. Unplug your TPS (when it's acting up). It'll throw a code but will put it an ECU controlled (no tps feedback) and see if the condition improves. A FSM outlines a bunch of tests you can do based on your symptoms. You can find full FSMs available for download on the web if you loook. You need one.

Shady Cadence

The issue you're looking for isn't between the connector and ground, but between the wire and the connector where it's crimped. If the wires are any color other than copper, replace it.

cpljenkins01

No vacuum leaks check for that already. New tps set where the factory one was. I am going to try and switch out my arm back to the stock one tonight. It has a 7 mge one on now.

cpljenkins01

Hardeline del take out a lot of vacuum line after doing the egr del. All the hardlines are under the upper intake.

bswarm

Did the problem start when you deleted the emissions controls? Put them back on, the EGR delete isn't going to gain you much horsepower if any, and may even result in having to use premium gas or retarding the timing to prevent pinging.

cpljenkins01

My timing is set at 13 degree where it's stock and I already use premium fuel.

cpljenkins01

The egr and hardline del didn't affect it cuz it did do it till about 4-5 months ago and I did all that line 10 months ago and it wasn't doing it then.

skypilot

iTrader: (1)

You know 3vze's as a rule tend to run rich. The fuel curve is pretty generous. I wonder, on a lark if your ecu has an internal issue. Or somehow the ecu is being lied to by the AFM. If there are no un-metered air inputs, someone is lying. Have you checked the outputs at the ECU? Other than that fuel pressure could be low, or the FP regulator is closing down too much in closed loop, and the ECU cannot overcome the low pressure by maxing out the injector signal.

Have you tried taking the vacuum line off the FP regulator? Let it run in "cold mode"?

Shady Cadence

Don't check that ground under your dash, replace it and try your truck.

I kid you not.

And if it doesn't want to idle afterwards, re-adjust your tps.

cpljenkins01

You talking about the ground at the driver side kick panel? That's the only ground I know of. What way do I need to turn my tps and what does it do whet I turn it either way?

Shady Cadence

There's TWO grounds there, one is two white with black tracers to twin connectors, the other is two brown wires going to a single connector. I advise you to replace both of them.

the other grounds for engine management are on the back passenger's side of the lower intake manifold. You can just see them if you look between the firewall and the upper intake from the passenger side.

cpljenkins01

Ok I will see what it does for me.

Shady Cadence

Just be sure you get a good solid crimp on nice clean wire, and see what it does. The brown ones are the main focus here, those connect to engine management.
In my 94 runner, those two wires, to that one little connector, caused a brutally hard sub-zero start, long crank time during any start, severe lack of power, failure of the ecu to recognize the throttle switch state, and eventually disrupted the ign signal so bad the rev limiter was engaging before 2000 rpm.

All those issues, caused by one...little...connection.

Try it. Let us know.