Q&A

Mailbag: Troubleshooting Timing Problems on a Pontiac 400 Engine

You’ve got questions. We’ve got answers. We work with the Summit Racing tech department to tackle your automotive-related conundrums. This week, we’re troubleshooting timing issues on a 400 c.i.d. engine swapped into a 1980 Firebird.

pontiac 400 engine timing

(Image/Hot Rod)

Q: I have a 1980 Pontiac Firebird with a 400-cubic-inch engine out of a 1978 Trans Am. The engine was built with parts from two different 400s, and the timing has never been right. The timing marks on the harmonic damper don’t line up properly with the pointer, and I’ve reset the distributor several times but it never lines up either.

The distributor is from the Firebird’s original 301 engine and the damper is from one of the 400s. Do I need to get a new distributor and damper?

A: We don’t think you need a new distributor. The distributor from the 301 should fit the 400 with no problem. We think your timing troubles could be caused by one of the following:

  • The outer ring of the harmonic damper may have slipped, causing the timing marks to move around. Not only does this make timing the engine nearly impossible, it can also be dangerous. A damper with this problem can fly apart at any time. If this is the case with your damper, you should replace it immediately.
  • On most V8 engines, timing is checked on the #1 cylinder because it is the first in the firing order. On Pontiacs, the #1 cylinder is on the driver’s side, which is furthest from the timing marks on the damper. A common mistake is to use the #2 cylinder on the passenger side because it is on the same side as the timing marks. Make sure you are using the #1 cylinder to time your 400.
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9 Comments

  1. Can 1989 carmro cylinder head work for the 1989 firebird Tran am

    • Hey Grumpy–In 1989, both the Camaro and Firebird/Trans Am ran versions of the Chevy Small Block, the L98 5.7L, the LO3 5.0L, and the LB9 5.0L. (You could also get the LB8 V6 too in base Firebirds/Camaros.) What engine(s) are you looking at?

  2. Another common mistake that I fell victim to is the distributor on the Pontiac turns counterclockwise because it’s on the opposite of the cam as a Chevy.

    • had this shit too right fucking now! goddamn v8 350’s, they look the same, but are def not, timing is also 12 o / 12 o unlike chevy 6 o / 12 o… very confusing, if you dont know u assume all engines do bit the same.. but they donnnt

  3. david j. barragan says:

    just rebuit 1969 gto 400,stroked to 496,comp cans 51-433-9 roller,hei distributor,new wires,plugs, engine runs but no. 2 cylinder does not fire. has 175 lbs. compression. any ideas?

    • OnAllCylinders Staff says:

      Hey David, it could be a myriad of things. Start with the easy stuff.

      Are you getting spark to the plug? If you have the old plug wires still, you can try swapping out the single new ignition wire to that cylinder with the old one to see if that changes anything. You can also try swapping the plugs around to see if the problem follows the plug. When you pull the plug is there fuel on the electrode to potentially rule-out a valve issue?

  4. david j. barragan says:

    paul,spark is there,every thing is new,including engine. #1 and 2 are not running.plugs are still white. pipes dont get hot. intake manifold and gaskets are fine.acts like 1 and 2 arent getting gas.???

    • OnAllCylinders Staff says:

      Sounds like you’ve eliminated most of the basic stuff. White plugs can mean that you’re running lean, which would follow your lack of fuel theory. Give the tech folks at Summit Racing a call, 330-630-0240, they’ll be able to better help troubleshoot over the phone.

  5. Pingback: Hot Rod Engine Diagram – Wiring Diagram

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