Most people nowadays who call themselves “car enthusiasts” often have little understanding of the actual maintenance required for their vehicles or motors. They rarely consider the longevity of their engines or the reliability of their performance. Since I’ve been into cars, I’ve always prioritized regular maintenance—oil changes every thousand miles, valve adjustments, ignition timing checks, coolant flushes, and transmission oil changes every 3,000 miles (or after every track weekend in the case of my race car). How can you expect your car to endure the abuse you put it through if critical components like these aren’t maintained?
It’s the same concept as with an athlete. They eat well, take supplements, rest, and recover to perform at their best. They can’t ask their bodies to give 100% without proper care. The same goes for cars—routine maintenance is essential to ensure reliability and performance.
When I first performed my D16Y8 swap into my EK, the wiring harness I was using didn’t have a plug for the charcoal canister. This would occasionally trigger a CEL (Check Engine Light) because the ECU wasn’t receiving data from the EVAP system. It was a bit annoying, but I discovered a workaround to prevent the CEL from coming on. The issue occurred if I didn’t touch the throttle for more than 8 seconds while decelerating. For example, when approaching a red light, I would perform a slight heel-toe action to briefly apply the throttle, which sent a signal to the ECU, preventing the CEL from triggering. However, this workaround was still inconvenient since it required extra effort while slowing down.
The real solution was to install an ECU jumper harness to convert from OBD2-A to OBD1, allowing me to run a P28 ECU. Since the P28 ECU doesn’t have an EVAP system, it no longer threw a CEL regardless of how long I decelerated without throttle input.
The P28 ECU is significantly different from the P2P OBD2A SOHC VTEC ECU I was previously using. The redline on the P28 is set at 7200 rpm, while the P2P ECU redlines at 6800 rpm. Additionally, the VTEC engagement point is 4800 rpm on the P28, compared to 5600 rpm on the P2P. Naturally, these differences in redline and VTEC points meant that the fuel and ignition maps were going to be quite different.
This caused my car to feel sluggish around the 5500-6000 rpm range, which was quite disappointing. I knew ignition timing could significantly affect both low-end and high-end power, so I decided to research and write a “how-to” article on adjusting ignition timing. These principles generally apply to most D-series engines, and I believe they’ll be relevant for B-series as well. For F/H/K-series engines, the process varies slightly, so maybe we’ll cover those in a future guide.
Step 1: Move your racecar out of the garage and pull your daily driver in.
Step 2: Bring your car up to normal operating temperature. Ensure it’s not in the cold map—usually, I wait until the cooling fan cycles off completely, then turn off the engine and remove the key.
Step 3: Locate your ECU on the passenger side footwell, remove the plastic cover, and find the blue two-wire jumper plug. It might be stored inside a green rubber “holder” to prevent it from making noise or rattling. If your car is relatively stock, it will likely still be in this rubber holder. If the car has had multiple motors or ECUs installed, the jumper plug may be loose and tucked away— you may need to search around as a previous owner might have hidden it. Trust me, it’s there somewhere!
You’ll notice the green rubber plug directly above the blue two-wire jumper. The two-wire plug is also what you’d use to “jump” for reading CEL codes.
Next, you’ll need to create a jumper wire, as I did, or use a paperclip. Insert it into the two-wire jumper plug.
Make sure the jumper wire is securely inserted— you don’t want it to come loose while adjusting the timing. The reason for jumping this plug is to force the ECU to run in base map mode. If you don’t jump it, the ECU may make its own adjustments while you’re trying to set the timing.
(Note: Jumping the plug will trigger the CEL, which is normal and indicates the ECU is running on the base timing map.) The CEL should remain on throughout the timing adjustment process. It will turn off once you remove the jumper wire.
Step 4: Grab your timing light and properly hook it up.
Run the power wires to the positive and negative terminals on your battery.
Then, attach the Hall effect magnetic clip to the cylinder #1 spark plug wire.
Step 5: Locate the timing marks on the crank pulley (on the driver’s side of the engine bay).
In the picture, you’ll notice a pointer mark on the timing belt cover, resembling a gun sight. From directly above, line up the three groups of score marks with the pointer. The red mark in the center is the one you’ll want to align.
Note that the picture doesn’t show the marks lined up—this is simply how the crank pulley stopped when I shut the car off. There’s a single mark on the pulley slightly off to the right, which is used for setting TDC (Top Dead Center) during tasks like replacing the timing belt, cams, water pump, or other components where the timing belt needs to come off.
Additionally, there are marks (or groups of marks) on the cam gear(s), depending on whether your engine is SOHC or DOHC. These marks help ensure the engine is at TDC before starting. If the cam gear arrows and TDC marks don’t align properly, don’t attempt to start the engine—incorrect timing can lead to valve/piston interference, making the entire timing process irrelevant.
For ignition timing, you’re only concerned with the group of three marks. The red “middle” mark is the one you’ll want to align with the pointer. The mark on the left, or “front” of the engine, is two degrees advanced, while the mark on the right, or “rear,” is two degrees retarded. Adjusting or retarding timing slightly can influence your car’s power delivery, but excessive adjustments can cause detrimental results, so proceed with caution.
Step 6: Loosen the three 12mm bolts holding the distributor in place. You only want to loosen them enough so you can rotate the distributor—there should be some resistance. These bolts will need to remain loose while the car is running so you can make the necessary adjustments.
Step 7: Assuming your mechanical timing is correct, start the car and ensure your timing light is working and reading RPMs. Make sure the car hasn’t cooled down too much since the previous steps. Next, adjust your idle speed—usually set to 750 rpm, but check the specific specifications for your application. Use the flathead screw on top of the throttle body to make the adjustment.
Make sure you’re referring to the settings for your specific engine.
Set your idle properly— as you can see, mine was set too low.
Step 8: Shine the timing light from the top of the engine, directing it straight down. The timing light will function as a strobe, making the pulley appear as though it’s momentarily stopped. Line up the red “middle” mark with the pointer on the timing belt cover. To adjust the timing, rotate the distributor clockwise to retard it and counterclockwise to advance. Moving the timing by just a few degrees doesn’t take much, so proceed with caution.
As you can see, I’m holding the timing light with one hand and rotating the distributor with the other. Once everything is lined up, tighten only one of the distributor bolts, then check the pulley to ensure the timing hasn’t shifted. If everything looks good, tighten the other two distributor bolts.
Now you’re all done. Remove the jumper wire, reinstall the ECU cover, check the distributor bolts (3), and ensure you haven’t left any tools in the engine bay or windshield cowl.
That’s it for now! I hope this guide has been helpful in getting your ignition timing set properly. Taking the time to ensure everything is dialed in can make a noticeable difference in your car’s performance. If you have any questions or need further assistance, feel free to reach out. Happy wrenching, and safe driving!
I can be reached via email at Billy@Functiontheory.com, Instagram @Functiontheory, or simply comment on the post below and I will respond.