So, the other day I was driving around and I started to notice some pretty solid detonation happening on acceleration in the Ghetta. Got home, popped the hood, and - to my everlasting joy - the hold-down clamp on the distributor had loosened off, and the whole dizzy was wobbling in a, well, dizzy fashion. So clearly, my ignition timing was off.
Of course, like most Joe Average backyard mechanic-types, I don't have a timing light. Now this is the point where most people phone up the Snap-On guy and invest in one, but my Snap-On guy is on vacation. So instead, we resort to the old mechanical standby: adjust, test, listen, adjust, test, listen, ad nauseum. Here's the method I used (and on testing with the shop timing light afterwards, I was only a hair off with this method).
So first you need to get the car up to what the Bentley calls "normal operating temperature", an 80 degrees celsius oil temperature. To do this, take 'er for a boot, or just let it idle, making sure the radiator fan cycles on and off at least once. This guarantees you're going to see your true timing results - since a colder engine detonates at different points.
Once she's all warmed up and ready, kill the engine and disconnect the Coolant Temperature Sensor (CTS):
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This is to make sure that you're adjusting the base timing, not what the computer is constantly adjusting based on engine temperature.
Start the car up again with the CTS unplugged. It'll be a rough start, but give it some gas as its struggling and the idle should even out. Don't worry too much about that idle speed at this point, we'll have to play with it later.
Now you want to tell the computer to stop screwing with your idle and fuel enrichment, and to do this, hop in the car and rev it up above 2100 rpm for a few seconds, then let it drop back down to idle. Do this three or four times, and you've bypassed the computer's hot-start high-idle function, so you're now at the honest idle speed. Keep the engine running throughout this entire process; don't shut it off until I tell you.
(Our CTS is still unplugged. Keep it that way till the end. DON'T PLUG OR UNPLUG IT WITH THE ENGINE RUNNING! Toasted ECUs can result.)
So to time the engine, what you want to do is start by getting your ignition pretty far advanced. Get under the hood and loosen the distributor hold-down clamp bolt with your trusty 13mm wrench. (If your 13mm isn't so trusty, a 1/2" domestical wrench will do in a pinch). Loosen it just enough that the dizzy starts to vibrate slightly. Now you want to turn the whole dizzy counter-clockwise (advancing the ignition) bit by bit until the idle speed starts to increase. Once it does, tighten that bolt back down.
Now without shutting it off, hop in the car and take it for a short trip around the block. Shift early, and put a lot of throttle in it, so you're pushing the car hard at low RPMs. You'll hear that knock happening. So, pull off to the side, pop the hood, loosen that bolt again and turn the distributor just a hair clockwise. You're backing off the advance, just a tiny bit. Don't go overboard, the difference between perfect timing and detonation/retardation is miniscule.
So tighten that bolt back down and take her for another boot around the block same as before. You'll notice the detonation has probably reduced. Keep up this drive-listen-adjust-drive-listen-adjust routine until the detonation is eliminated completely.
Now, we're not done with this yet. Let's check the idle before we call our timing set. What you want to do is back off the jam nut on the idle screw (on top of the air intake, at the rear top of the engine) a bit at a time, while checking the tach in the car. What you want is to get it just a hair below 1000 rpm. Once we plug the CTS back in - LATER - the idle will drop to normal spec.
With the idle set, take it for another run around the block - this time driving like a normal person. See if the car feels gutless or lacking throttle response. If it does, that means you've retarded the timing too much. You might have to turn the dizzy back a bit counter-clockwise again, a hair at a time, with test rides in between, adjusting the idle each time, until you find the perfect spot. What you're aiming for is no detonation, but also no loss of power. That's your properly set timing.
![Image]()
Now you can shut the car off.
Now that your timing is good and your idle is still sitting just below 1000 rpm, you're ok. Give that dizzy bolt another crank just to be sure it's tight (we don't want to have to do all this BS again) and tighten down the jam nut on the idle screw (making sure of course that the idle screw doesn't turn with it). Reconnect the Coolant Temperature Sensor, and start her up. Do the rev-to-over-2100-thing three times again, and your idle should drop to right around 750 RPM, where it should be.
That's it! Take it for a rip and enjoy your newly-timed car!
![Image]()
Of course, like most Joe Average backyard mechanic-types, I don't have a timing light. Now this is the point where most people phone up the Snap-On guy and invest in one, but my Snap-On guy is on vacation. So instead, we resort to the old mechanical standby: adjust, test, listen, adjust, test, listen, ad nauseum. Here's the method I used (and on testing with the shop timing light afterwards, I was only a hair off with this method).
So first you need to get the car up to what the Bentley calls "normal operating temperature", an 80 degrees celsius oil temperature. To do this, take 'er for a boot, or just let it idle, making sure the radiator fan cycles on and off at least once. This guarantees you're going to see your true timing results - since a colder engine detonates at different points.
Once she's all warmed up and ready, kill the engine and disconnect the Coolant Temperature Sensor (CTS):
This is to make sure that you're adjusting the base timing, not what the computer is constantly adjusting based on engine temperature.
Start the car up again with the CTS unplugged. It'll be a rough start, but give it some gas as its struggling and the idle should even out. Don't worry too much about that idle speed at this point, we'll have to play with it later.
Now you want to tell the computer to stop screwing with your idle and fuel enrichment, and to do this, hop in the car and rev it up above 2100 rpm for a few seconds, then let it drop back down to idle. Do this three or four times, and you've bypassed the computer's hot-start high-idle function, so you're now at the honest idle speed. Keep the engine running throughout this entire process; don't shut it off until I tell you.
(Our CTS is still unplugged. Keep it that way till the end. DON'T PLUG OR UNPLUG IT WITH THE ENGINE RUNNING! Toasted ECUs can result.)
So to time the engine, what you want to do is start by getting your ignition pretty far advanced. Get under the hood and loosen the distributor hold-down clamp bolt with your trusty 13mm wrench. (If your 13mm isn't so trusty, a 1/2" domestical wrench will do in a pinch). Loosen it just enough that the dizzy starts to vibrate slightly. Now you want to turn the whole dizzy counter-clockwise (advancing the ignition) bit by bit until the idle speed starts to increase. Once it does, tighten that bolt back down.
Now without shutting it off, hop in the car and take it for a short trip around the block. Shift early, and put a lot of throttle in it, so you're pushing the car hard at low RPMs. You'll hear that knock happening. So, pull off to the side, pop the hood, loosen that bolt again and turn the distributor just a hair clockwise. You're backing off the advance, just a tiny bit. Don't go overboard, the difference between perfect timing and detonation/retardation is miniscule.
So tighten that bolt back down and take her for another boot around the block same as before. You'll notice the detonation has probably reduced. Keep up this drive-listen-adjust-drive-listen-adjust routine until the detonation is eliminated completely.
Now, we're not done with this yet. Let's check the idle before we call our timing set. What you want to do is back off the jam nut on the idle screw (on top of the air intake, at the rear top of the engine) a bit at a time, while checking the tach in the car. What you want is to get it just a hair below 1000 rpm. Once we plug the CTS back in - LATER - the idle will drop to normal spec.
With the idle set, take it for another run around the block - this time driving like a normal person. See if the car feels gutless or lacking throttle response. If it does, that means you've retarded the timing too much. You might have to turn the dizzy back a bit counter-clockwise again, a hair at a time, with test rides in between, adjusting the idle each time, until you find the perfect spot. What you're aiming for is no detonation, but also no loss of power. That's your properly set timing.
Now you can shut the car off.
Now that your timing is good and your idle is still sitting just below 1000 rpm, you're ok. Give that dizzy bolt another crank just to be sure it's tight (we don't want to have to do all this BS again) and tighten down the jam nut on the idle screw (making sure of course that the idle screw doesn't turn with it). Reconnect the Coolant Temperature Sensor, and start her up. Do the rev-to-over-2100-thing three times again, and your idle should drop to right around 750 RPM, where it should be.
That's it! Take it for a rip and enjoy your newly-timed car!
