First off i thank everyone for the help!! Here is what i have a a 1984 fj60 landcriuser that i put a 93 tbi with a nv4500 i used a howell wiring harness and ramhorn manifolds with 2 1/2 duals all the way out and a vss sensor tire size is 35's here is what ive done and the symptoms im having.


symptoms

1. All of this started slowly this thing ran like a top for the first 4 months with no problems at all then slowly it developed this miss!!

2. hesitates/bucks/cutouts under load always in 3rd through 5th but its getting worse and now sometimes does it in 2nd

3. rpms at idle jump up and down 1 to 2 hundred rpms from time to time.

4. in the last two weeks it has developed a bad hesitation when cold when im starting out from a stop in second only does it for a few seconds!


5. I have zero error codes!!

6. All of this Except number 4 only happen when the motor is warmed up! When the motor is cold is runs pretty decent!!


Things I have done

1. replaced every sensor on the motor except the iac all of them that i bought were the top higher priced one NOT the cheapos

2. Rebuilt the tbi unit and put new injectors in it!

3. replace the entire egr setup and it works good now!

4. changed out the one wire 02 sensor for a 3 wire heated setup

5. put a inline fuel gauge in im getting 13.5 psi

6. changed the entired ignition system out(when i changed the plugs one of the electriods was burnt clean off its been fine ever since)

7. timing chain does not seem to have much slack in it

8. checked for vacuum leaks about five times now and havent found one!!

9. changed the fuel filters

Thats all i can think about right now if it helps with the data reading it was about 34 deggrees out when i did the log and it was a combo of town country and highway driving im not sure if you need the blm's if so i have those as well again thanks for all the help ive been stumped on this one for about 3 months now and its seriously driving me nuts!!!

 

Looks like something is off in the tune. You have knock counts increasing slowly through the log file and it looks like its running a bit lean. Is the engine stock and is the ECM and prom you are using correct for the engine?

 

thanks for the reply yes the engine is stock it has about 180,000 miles on it the ecm was what came out of the truck that i got the motor from! the knock counts are weird if timing is set at zero (which is where it should be) then there doesnt seem to be many knocks counts but the kicker is that it runs like crap at zero so i move it to 6 where it runs the best but then the knock counts go way up!! so with all the data that you read what do you think i need to do to fix my problem?

 

Its running lean which can be caused by lots of things. Do you have the right injectors? 305 and 350 injectors are different. Also the coolant temp hovers around 170 which is kind of on the cool side. I'd use the stock 195 degree thermostat if you are keeping everything on the engine stock. Basically if you are not gonna get into prom tuning you will have to keep the engine pretty close to stock.

 

ya i did change the thermo stat the other day back to a 195 didnt make any differnce! It has a few mods but nothing extreme full exhaust ram horn manifolds but thats about it! as for the injectors i assume they are the right ones but i guess not 100% they are what the parts store gave me! and the spray pattern is nice and even! i dont know why it would run lean i have 13.5 psi new walbro fuel pump new filters rebuild throttle body?? one weird thing is if i pinch the return line the motor will cut out and die then it doesnt want to start again for about 30 seconds like it got flooded out!!

 

A couple years back my engine ran lean to a point it would struggle to run at x way speeds. We replaced the coolant sensor and map sensor. Map sensor very old. Fixed the issue. A failing coolant sensor is typically adding mucho gas as ECU sees cold coolant temps. So I believe it was MAP sensor. I would test Map sensor.

 

ya thats pretty much what mine does it runs great around town but is pretty much undriveable on the highway!!! shouldnt i be able to tell if the map is working from my data logs though???

 

Yes I would expect so. I did not have the convenience of time to fool with it as far as datalog as I was close to being stranded. My WB clearly showed 17/1 where prior was 14.5 to 15.0. So parked it and replaced both sensors. It worked.