1994 TBI 350 Stretched Timing Chain

[megafan0258]

No but, you need to disconnect the battery to reset the EST fault you get from disconnecting the BLK/TAN wire.

Any idea why my Block Learn Multiple would be so high? Never seems to get near 128.

 

[PlayingWithTBI]

Any idea why my Block Learn Multiple would be so high? Never seems to get near 128.

That means you're running lean. It takes time to level off IF you have enough fuel pressure and everything else is good, like your O2 sensor.

 

[megafan0258]

That means you're running lean. It takes time to level off IF you have enough fuel pressure and everything else is good, like your O2 sensor.

Thats what I was assuming from what I read but wanted to confirm.

Fuel pump was replaced with a Delphi unit and pressure was good but I havent check for volume.

It has a BLM of 135 on start up and went in and out of closed loop a couple of time after about 160 degrees.

Also does the computer take 02 into account in open loop? If not then I would assume I have a fuel delivery issue.

What are normal values to have in closed loop for a TBI 350?

Thank You for the response.

 

[PlayingWithTBI]

Also does the computer take 02 into account in open loop?

No, it runs off your VE tables.

What are normal values to have in closed loop for a TBI 350?

Acceptable numbers are 121 - 135 or there abouts. Got a scanner? Look at your O2 feedback and "Cross Counts"

 

[Schurkey]

Does the battery need disconnected (to reset computer) after messing with the initial timing to reset timing curve? Or is that not a thing?

You missed the "to be" in between "need" and "disconnected".

And I have heard that disconnecting the battery--which erases all the volatile memory in the computer--can make a sudden, dramatic improvement in vehicle performance.

I worked on a Ford Focus about a month ago that ran horribly, and got 80+ percent "fixed" by deliberately giving the computer amnesia. The remaining 20% is still bugging me.

The eBay junk I bought is the injector coil balancer tester, selector switch box, and the 4.3 harness. I was surprised at how relatively cheap it all was. I plan to keep this truck for a number of years so I like having the diagnostic tools available.

Yup. If you have the tool, you probably want to get additional harnesses so you can use it on additional vehicles. In a perfect world, you'd pay for that tool plus some extra--or become a local hero--by performing diagnostic time on other's vehicles.

No but, you need to disconnect the battery to reset the EST fault you get from disconnecting the BLK/TAN wire.

It does that, too.

Clears volatile memory
Clears codes

 

[1998_K1500_Sub]

I had an odd ignition timing situation on my 1995 S10 Blazer, which I chased for years.

Read the story here, about how the reluctor wheel on the distributor shaft crept SLOWLY over time (years):

https://www.gmt400.com/threads/1993-chevy-c1500-4-3-power-issues.62069/post-1313440