NEED SOME INSIGHT

[1963korvette]

I need some help from the brain trust

I scanned the motor last night and got no DTC's, almost everything looked normal when compared to our "reference" page in section 6E with the data snap shot.

Here are some of the scan data in closed loop @ idle that I thought was not too great, and by the book it appears not to be too good either when I looked it up.

Block Learn enable = YES. book says it should be NO.

BLM cell = 16 ???? book says it should be 0 - 1.

Left BLM - 127 to 128
Right BLM - 136

Left Integrator counts were from 127 thru 133
Right Integrator counts were 126 thru 131

MAP reading in volts was 1.5 volts which is out of the book range of 6v to 2v.


Oh yea, his tach is about 1k rpms fast, how do you fix that?

[jonszr1]

was the car warmed up when you read her , blk learn being open only until i believe 167 170 deg .then goes to closed loop . everything else to me looks good except for the map sensor . but mine reads that but i am at 4k ft . remember neutral on the blk learns is 128 . and the short terms will bounce around a bit .there are others that know tons more than me . hope this helps

[1963korvette]

thanks for your reply. The car was completely warmed up. The engine has a hiccup that you can set your watch to. It idles smooth and then dips down to almost stalling than returns to idle and does this in an almost perfect rythme.

Thanks Rich

[-=Jeff=-]

Right side is running a bit lean.. How old or injectors? how old are the O2 sensors..

[1963korvette]

I've been working with Tomtom72. He actually did the readings and was a little stumped by the numbers and had me post them. In the interm I replaced the Injectors on Sunday. The car seems to be acting the same why it did before replacement. As far as the o2 sensors I would assume are originals as injectors were.
Thanks
Rich

[-=Jeff=-]

those the #s from after the injector swap?

if not you need to scan again to get the current readings

Did you replace the coils?

[1963korvette]

unfortunately, no. I will scan tonight and post numbers tomarrow.

[1963korvette]

New reading
BLM cell 16
Left o2 27
Right o2 75
Map 1.88
Map KPA 45
Int counts Left 128 right 128
Idle 750 and drop to 525

Hope someone can give me some answers .....PLEASE
Thanks
Rich

[-=Jeff=-]

Rich, what are you using to capture the data? if you are able to log data ( more then a snap shot) it will help..

What is the BLM # before it was L127 and R136, what is it now?

Have you done plugs wires and Coils?

[Jeffvette]

MAP reading in volts was 1.5 volts which is out of the book range of 6v to 2v.


The MAP range is actually .6V - 2.0V, so 1.5V is within range.

Taking a snapshot is not giving us the whole picture. It would be nice to have a complete scan showing about a 2 minute idle so we can match up the data with the RPM drop and something else.

Your BLM is supposed to be at 128, which is the median. 118 is rich and 128 is lean

What are the integrators doing, which are the short term fuel trim #'s?

One thing I will say to watch is the O2 sensor fluctuations. You are looking for rapid changes. If it is hovering on numbers for a couple of cycles, the O2 is pooched.

Also, since I assume this car has been sitting around for a while and you are correcting several problems, take the time to change the fuel filter as well.

[1963korvette]

Thanks for answering my post guys. Tomtom72 lent me his snap on scanner (actualy he forgot it). The car had new wires and plugs before I bought it. He had work done by Chevy dealer. The coils look like they are originals. I will talk to Tom about how to get more info on the scan. Replaced the injectors with bosch rebuilts last weekend, guess I should have also replaced coils too. I believe the fuel filter was changed but seems a pretty easy thing to change. What do you expect from a dinosour from the 60's. Never to late to learn.

Thanks
Rich