Jump to content

1987 Silverado 350 Tbi Timing


Recommended Posts

Posted

I do not have an emissions label on my truck. I need to set the timing as I just rebuilt the engine. I looking in my Tune Up guide at work but the book stopped in 84.... Clearly missing the boat on EFI and computer controls...

 

I know I need to disconnect the EST wire... I think I found it when I was wire looming all the engine compartment under the master cylinder... My big question is what to set the timing on. 0 degrees? 2? 4? 8? 16? 32? 64? 128? 256? 512? 1024? 2048? 4096? (the 31337 group know what the powers of 2 come from).....

 

Anyways guys if anybody knows what to set it at let me know.... I'd like to get my truck buttoned all together this weekend.

 

Thanks,

Jbo

Posted
mine is a 4* or 6* pulls strong and hard.

i am interested in this, did you notice better mpg, better power, have to run higher octane fuel, bump fuel pressure, did power come on sooner? thanks for any help, i need to check timing too and was also going to post a thread asking basically same question.

Posted

I run 93 oct,For what i got in the motor and it not being "performance oriented" motor she gets up!had it up 80 in 3rd soon as it hitted od i had to stop for traffic.As for adjusting timing go for it.But i wouldn't go any thing above 8* advanced or you might have some spark knock.Try it at 4* then 6* see which feels better.

Posted

I set the timing today. I found the EST connector under the brake booster taped to the bulk head going into the interior of the car.

 

This is the type of connector (Weather Pack)

205_WPT-1-203.jpg

 

This is the half that is taped to the harness.

205_WPS-1-203.jpg

 

I unplugged the connector and set the timing to 0 degrees. Tightened the distributor back down. And rechecked and plugged the EST back up. It stayed at 0 for just a second after I plugged the EST back up then moved up just a bit, after a few seconds.

 

Maybe I should snap some pictures of the EST wire location. It is a Brown with Black stripe wire. NOT THE Brown with White stripe.... Brown with White stripe kills the injectors..... Ask me how I learned that, but most of you figured out how I learned that.

 

Jbo

Posted

Brown w/black stripe with that connector is correct. Engine off, disconnect that connection, start engine, set timing to 0°, engine off, reconnect timing connection, done.

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,840
    Total Members
    8,960
    Most Online
    appletrav
    Newest Member
    appletrav
    Joined
  • Who's Online   1 Member, 0 Anonymous, 316 Guests (See full list)

  • Latest Articles

  • Posts

    • This is a 1/2 ton thing ONLY.  All HDs 2020-2026 have the two speed transfer case, with Autotrac as an option.     1/2 tons 2019-2026, regular 4x4s come with a single speed case (no 4LO!), and trucks with Z71 ordered, or all Trail Boss trucks come with the 2 speed case.  2 speed case is also an option on WT, and is also standard on High Country.  
    • 2013 5.3 still to this day calls for the PF48 filter.  Which as a 15psi bypass pressure.     There is a TSB, 17-NA-157 that talks about the PF-63 and PF-64 filters which have a higher bypass rating of 22psi.    TSB HERE - temp.xml   "Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of pump out pressure. This means that the oil pump now does not begin to regulate until pressure is built up to the main gallery. This change reduces the amount of time it takes to provide oil to the engine bearing and lifters during extreme cold start conditions.  Main gallery feedback oil pump control systems are present on the following engine families which use Spin-on oil filters: Small Gas Engine (SGE), Large Gas Engine (LGE), High Feature (HFV6) Gen2 and Small Block Gen5 gasoline engines. These engines with the main gallery feedback oil pump control systems are factory built with an ACDelco® oil filters"   It also calls out what engines use those filters.  The gen 4 small blocks were not on that list (LMG, LC9, L9H, L92, L94, L20, L96).  Gen 5 small blocks use the higher pressure filter.          That all said...   Your 7045 Napa filter is the PF63 equivalent, with 22psi bypass.  You are already using the higher bypass pressure filter.  You CAN keep using it, you don't technically have to use it though.  
    • Do you know WHY the filter relief setting was increased to 22 psig?    When the new system goes into the second stage the pump volume ramps up considerably. It was found that the 15 psi filter bypass setting put the filter in bypass on a warm engine when the second stage was activated. Raising the filter bypass setting forced the filter to do what it designed to do. Filter. Preventing debris from circulating during high load, high rpm operation.    So next question is how did GM find this out? VLOM/lifter failures and a deep dive by Melling Corp.    Last question. Is it required? Look at it like this; a motor may be equipped with a rev limiter. But it only works if the set point in reached. That 22 psig setting only matters if the pressure differential across the filter media exceeds 15 psig during normal warm operation. Second stage kicks in around 3000-3500 rpm.    I can't answer your question because I don't know you and how you use the truck. But I think there is enough information here to let you decide for yourself. 😉
    • Probably not their first rodeo, so it should go as planned most likely.  Typically the service manager or tech doing the swap will put some seat time to shake it down after they get it all put back together.  We usually put 50-100mi before we hand them back so if something happens, its not after you get it.  A coolant leaks, oil leaks, a ground left off or loose, vibration, etc.     The new engines so far have been good?  There's been a couple that have popped out there again (the replacement engine) but most have been okay.  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...