How to Set timming

[Drova]

How do i set timming on my 87 S10 with 2.8L motor?

[BlazerLT]

Remove timing wire from PCM.

Use a timing guy and set the timing to 0 degrees.

Reconnect the timing wire and remove the negative battery cable for 5 minutes.

Start it up.

[dugie6551]

Originally Posted by BlazerLT

Remove timing wire from PCM.

Use a timing guy and set the timing to 0 degrees.

Reconnect the timing wire and remove the negative battery cable for 5 minutes.

Start it up.

How do you set the timing for a carburated motor? (1984, 2.8L)

[OverBoardProject]

Originally Posted by dugie6551

How do you set the timing for a carburated motor? (1984, 2.8L)

I don't know what the book sayes, but I just set my 85's timing by setting up the light on #1 didn't remove any wire, and set it to 12 degrees btdc, which is what they show on my under hood label.

It runs great, and sounds right. Plus I get decent mileage.

I hope that this gets your truck running, although I'd be suprised if it's your main problem.
Good Luck

[sector95]

Originally Posted by dugie6551

How do you set the timing for a carburated motor? (1984, 2.8L)

You do it the old fashioned way. Clean off the timing plaque and also the index groove on the engine crank pulley. Look for the appropriate setting on the plaque; for a manual trans truck base timing is 6 deg BTDC: auto trans is 10 deg BTDC. Warm the engine (choke is fully disengaged) and check/set the idle speed; 1000 rpm for manual or 750 rpm for auto.

Remove and plug the vacuum line from the vacuum advance canister located on the side of the distributor.

Loosen the distributor retaining clamp bolt; this will be made much easier with a distributor wrench (check local auto parts stores). You'll need a 15mm wrench.

Using an inductive timing light, clamp the inductor around the #1 plug wire (right front plug as viewed from the front of the truck). Aim the gun at the timing plaque and check. Make any corrections by turning the distributor; it'll be obvious which way you need to to turn. Set base timing per specs, tighten distributor clamp; recheck timing (reset if it changed). Once you're satisfied, shut off the engine, disconnect the timing light and reconnect the vacuum advance line.

You're done!

mike

[sector95]

Originally Posted by Drova

How do i set timming on my 87 S10 with 2.8L motor?

Hopefully you've still got the emissions decal present and readable. That will give you the correct parameters for your truck. Arbitrarily setting the base timing to zero may not be correct for your truck; use the setting specified on the decal.

You will have to disable the EST (electronic spark timing) and this is typically done by disconnecting the timing bypass wire. This is a single, brown or tan wire with a black stripe on it. It will typically be pulled out of a wrapped wire bundle next to the distributor and have a squarish, in-line connector along its legnth... or it may be located under the dash just under the heater case in the passenger footwell. Sometimes this wire is a bit of a booger to find...

With the 2.8L, it will be a big help to have a distributor wrench. You can get these at a good auto parts store or check out Sears tool department. You need a 15mm wrench.

Make sure the enigne is at normal operataing temp. Check the curb idle (specs as per the emissions decal). Disconnect the timing bypass wire. Connect an inductive timing light; put the inductor "clamp" around the #1 wire (right front wire as viewed from the front of the truck). Clean off the timing marks on the block and the index line on the crank pulley. Clear the fan and belts of any wires and start the engine. Take aim at the timing marks and see what you get. If adjustment is needed, loosen the distributor clamp and rotate the distributor; it'll be obvious which way to turn it. Once base timing is set, tighten the distributor clamp, recheck the timing and if it's still good, shut dowm the engine. Disengage the timing light and reconnect the bypass wire. You may have a check engine light but that should go out once the computer gets the right timing inputs.

mike