Timing ? on a 1988 Chevy K1500 5.7

[scarver]

This is my son's truck and he let it get pretty hot awhile back, and caused one of the heads to crack. We just replaced the heads on this engine, and after putting everything back together, I'm pretty sure the timing may be a little off as it's running rough and dies on acceleration. A neighbor has told me that I could borrow his timing light, but I haven't set the timing on an engine in over 20 years. I'm not sure if the Haynes manual willl detail the steps involved or not, but If I remember right, I put a chalk mark on the harmonic balancer. I then hook one of the timing light leads to the battery, and I'm not sure about the other lead (maybe the #1 spark plug?). I believe I then loosen the distributor lock bolt and start the truck to check the timing. Is there anything I'm leaving out. Does anyone know what the timing should be on this truck?

Thanks for the help.

[cburcham73]

its set from factory at 0 degrees. timing light clamp on #1 wire.i usually advance it a tad just under spark knock. ALSO........ if your heads cracked i would make sure your block is ok. ive seen the cylinders glaze up and you have zero compression.

[gmctrucks]

Welcome and howdy from TEXAS. And look at the passenger side of the fire wall there is going to be a insulated cover that one has to remove to get to a brown wire disconnect it before you set the timing there is also a fuse in there for the fuel pump this is just to give you an idea that your in the right area. Don't forget to connect the wire back.

[brad4eva]

GMC~ I'm curious , whats that step for? Whenever i set my timming i didn't do that :S what happens if u dont

[bradrhale]

88 is TBI. this fuel injection used a base timing to set by. you must unplug this otherwise it will not be correct as the engine sets its own timing when going through the ranges.

[brad4eva]

Hmm. My 93 blazer is also a TBI.. maybe u can explain to me how to put in timming by timming light step by step? ill love you can u help a poor fat kid

[brad4eva]

an update on my dilemma.. i tried unplugging that wire and the timing is the same u know what i m ean it stays at 0* tdc pluged or unpluged

[silverhairdeere]

Originally Posted by brad4eva

an update on my dilemma.. i tried unplugging that wire and the timing is the same u know what i m ean it stays at 0* tdc pluged or unpluged

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shd

[brad4eva]

that states nothing on why there isn't a difference on plugging and unplugging that "est" wire?b

[mudseeker]

if you still have that knock sensor code, that might explain it.