noclinkers

First off, I know this is not a dedicated Chevy site, but there is a lot of knowledge here, and I thought there might be someone who has had a similar situation.

Specs: 90 4Runner with exo cage, 5spd, dual cases,5:29 axle gears, 36" tires on steel rims with Stauns. It Weighs 5,132 lbs

I have a 92 4.3 CPI. The wiring harness, prom and ECM are from Howell industries and all new as well. In fact, everything on the motor is new including injection assembly, sensors, and ignition.

After I got it running, I hooked up the scanner to check things out, and although no codes are present, it is running rich and the integrator and block learn are very high. BL 160 and Integrator 140. It also seems like it should have a lot more power as it has less power than the 3slow had with 260,00 and it is only getting 12mpg.

I have checked for vacuum leaks with a smoker. Plugs look good. Timing is set at 0* It has less than 200 miles on the motor.

I cannot figure this thing out and it is driving me crazy so any help would be appreciated.

james92toy

Im running almost the same set up as you. 92 4runner 94 gm 4.3 cpi l460 35" tires 4:88 gears. Had mine weighted at 4900 pounds. Everything has been rebuilt , runs great and is a hell of a lot faster than the old 3.0 . I average 12 to 14 mpg trying to keep my foot out of it. 16 to 17 mpg hwy at 65 mph.
I wonder what would happen if you put in a stock prom.

What is this "integrator and block learn are very high. BL 160 and Integrator 140" ?

noclinkers

If I understand things correctly the block learn is the long term fuel trim and the integrator is the short term fuel trim. I have been using these numbers to tell me when the ECM is adding fuel or taking it away.

Edit: 128-132 is normal higher means the ECM is reading a lean condition and adding fuel.

GVX

I had a similar situation, my bl and interrogator was similar. It was cam timing in my case the crank gear was on backward making the cam timing off app 5 degree's. Could be maybe one of those 3 key-way timing gears indexed wrong? If you can find your cam grind spec's you can check it with a degree wheel? Also check your compression and see if it is low I think this was my first clue like 90-95 psi if I remember correct. Is it a stock cam after market can have too much overlap for the ecm to compensate which would exhibit high bl and int readings.? Also make sure your MAP,TPS,and MAF reading's are typical even tho they are not setting codes. Low IAT readings will not set a code unless it is reading below -30. Another thought is try setting your distributor timing by ear in case the timing mark on your harmonic balancer is mis-indexed. If it runs better at +5 or higher I would still degree the cam

GVX

I think normal is supposed to be closer to between 110 and 120 and yes it is adding fuel and no it is not necessarily seeing a lean condition it is looking at other factors to determine the bl and int readings. to try to simplify it Look it like you have a square box of cubes the far upper corner being cube 1 and the near lower corner being cube 200 with the TPS,MAP,and O2 sensors creating + and - forces on each side to calculate which cube to set the fuel factor with the middle cube being the idea theoretical fuel trim and using the opposing forces to calculate the real world fuel trim cube. There are several other forces used to determine the fuel trim but I use the cube example to simplify explanation. instead of trying to explained a 28 sided ball shaped grid with 14 positive and 14 negative sides. You see where I am going now?

noclinkers

That is awesome information,I appreciate it so much!!

GVX

please let us know if and what solves the problem CUL