Dreidel

Ok I have a 95 22re pickup. I like I gets me from point a to b but its been having problems lately. when I first get into the truck it runs great its like nascar untill it warms up. basically when the ecu switches from open loop (preprogramed map) to closed loop (using sensors to make maps) bare with me I might have it backwards. anyway when the ecu jumps to using engine sensors to set parameter it starts running like crap no acceleration. Engine sounds like its starts to get a load on it barely accelerating and then stays like that throughout the pedal range without changing toneslike it usually will. (to describ in simple terms what happens it feel normal when the motors cold but when it heats up to normal temp its going from a v8 to 4cyl instantly and its kinda aggravating).
Any way I'm not sure where to start looking I think its clearly a sensor that is a sensor that sets fuel, air, or possibly spark related when the ecu is in open loop imo
Any help would be appreciated and somebody let me know if I have that backwards and ill edit to correct it thanks

scope103

Yes, you have it backwards. The cold engine runs in open loop until the O2 sensor gets warm enough to give a usable signal that allows the ECM to "close the loop."

I assume you don't have any codes, and that your CEL (Check Engine Light) does illuminate with Key-on, Engine-off. The simplest problem that would explain all your symptoms is ignition timing; a $20 timing light will tell all.

PS there are two brand-new inventions that will help you get better answers to your truck-mechanical questions. The "period" and the "comma."

Dreidel

Ok thank you ill have my buddy bring a timing light over tonight or tomorrow. Those inventions sound handy how do you use them? Lol

Gamefreakgc

If timing is not the issue, your next step would to get a multimeter ($5-$10) and start measuring the resistance of your sensors. Use this as a reference: http://personal.utulsa.edu/~nathan-b...sm/engine.html

You'll want to check your Volume Air Flow Meter, Engine Coolant Temp sensor, Throttle Position Sensor (need a feeler gauge for this one, $4), maybe even the Cold Start Injector Switch. Basically any and all sensors until you find the culprit.

Dreidel

ok well we will see i adjusted the timing today a couple of degrees. i guess we will see what happens from here it was running kind of hot too. i thought it was a sticking tstat, broke right now so i took it out and it still kinda runs a liitle hot compared to normal. i turned the dist. ccw a few degrees and it already sounds better.

Terrys87

iTrader: (1)

Besides what has been mentioned, have you tried burping the system? I raise the front end up where the radiator cap is higher then the back of the motor to get any air that is trapped in back out. Let it idle until it has cycled the thermostat a few times.

Sometimes just giving the sensors a good cleaning can help as well as they can get that green build up on them. (The sensors that deal with water).

Dreidel

Its running lots better. I think it could use a bit more on the timing. the mpgs went up and its got lots more power I don't have very good luck with a timing light because the cam has been advanced 2 teeth. I've been told that if you mess with cam timing you throw a timing light out the window. For a 22re its kinda zippy, when everything is set up right it will walk away from 5.7 sbc in a ext cab truck and will keep up with a vortec in same type of truck. Not bad imo. I think last time I timed it I didn't tighten the bold on the dist all the way and when it gets into the higher rpms (5500ish) it was slighlty turning the dist and turning ir our of time, just a guess though cause the bolt wasn't real tight when I messed with it today

Dreidel

Yes as I discovered yesterday I have a slight crack in the waterneck. Guess I gotta go find my spare in my toyota part stockpile.