The importance of distributor timing


Vtec6000

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I wrote this for a thread on another forum but figured it might be beneficial to member's on here.

I had a situation recently where a previous customer had his car in for some work and since it was over 2 years ago that I tuned the car we decided to give it a run on the dyno to check how it was running. Straight away I noticed the engine was pinking/detonating pretty bad. I got my timing light out and checked the distributor timing, I found that the distributor had been over advanced by 6 degree's!

I rang the owner and he informed me that some months ago his distributor packed in so he replaced it with a working second hand distributor and didn't think any more of it. Luckily in this case no engine damaged occurred as the car wasn't driven much but it got me thinking about how many other people replace distributors without giving a taught as to where the distributor should actually be positioned.

I've often heard people say to position distributor so that the fixing bolt is center of slot to set timing correctly. This is NOT CORRECT

Any time a car comes in for mapping we set the base distributor timing at 16 degree's BTDC as per service manual. Now say that you end up changing distributor at some stage and the position you put it back on is at 20 degree's what you have effectively done here is add 4 degree's timing across your entire map, this can be detrimental to your engine.

So here is a guide for you to follow on how to set your ignition timing on a B series engine.

1. Run your engine until it's up to operating temperature.

2. Make sure your idle speed is as normal, a high idle will effect your timing values.

3. Locate the 2 pin service connector and bridge the 2 pins with a piece of wire.



4. Connect your timing light to cylinder 1 spark plug lead.



5. On the stock crank pulley there is 4 marks total, The 3 marks closest together represent 14,16,18 degree's BTDC. The other mark is 0 degree or TDC. If you are finding it difficult to see the marks I would manually rotate crank until the 3 marks are within sight and then I would highlight the middle of those 3 marks which would be 16 degree's(what you will be setting base timing to).




6. Point the timing light down at crank pulley and view where the middle mark(16 degree's) is in relation to the pointer on your timing belt cover. If it is not lining up loosen the 3 bolts on distributor and move it until the 16 degree mark lines up with pointer. Re-tighten your distributor bolts, disconnect whatever you used to bridge the service connector and your done.




So next time you change a distributor please remember to set the distributor timing correctly.


Note: If your car has been tuned using Hondata, Neptune, Ectune etc check with your tuner before setting your distributor timing as the service connector input may have been reassigned to control a different function.
 

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ijwhiteman

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Out of interest does that also include tuned/built engines or just OEM?
 

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Vtec6000

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Out of interest does that also include tuned/built engines or just OEM?
Yes it does but with the likes of Hondata s300 you are better off locking the timing in software as the service connector may have been assigned as a input to control a different function.
 

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KieranEG6

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Great to see this highlighted. Got stuck into this on a load of my cars last year. Alway had mine roughly set to the old bolt marks on hondas in the past. Until I had to replace the CAS seal on my supercharged Mx5, thought it was time I bought a decent timing light. How glad was I that I did!!! Turned out the last owner had set it to around 25'-30' BTDC no wonder he went through 2 engines!! he must have been guestimating the timing (badly).

Checked all my cars soon after to find each one out of spec. Fair bit of difference once adjusted correctly.
 


Vtec6000

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Great to see this highlighted. Got stuck into this on a load of my cars last year. Alway had mine roughly set to the old bolt marks on hondas in the past. Until I had to replace the CAS seal on my supercharged Mx5, thought it was time I bought a decent timing light. How glad was I that I did!!! Turned out the last owner had set it to around 25'-30' BTDC no wonder he went through 2 engines!! he must have been guestimating the timing (badly).

Checked all my cars soon after to find each one out of spec. Fair bit of difference once adjusted correctly.
Yes unfortunately it is over looked all too often. I've seen car's come in from been tuned elsewhere and found the distributor timing to be set wrong, in most cases I would guess they didn't check/set the timing at all.
 


dhdavectr

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I've done the timing on a few civics now, usually a while after a distributor has been fitted and set wrong.

Usually the owner says the garage had fitted it and said it was fine.
 


ijwhiteman

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Yes it does but with the likes of Hondata s300 you are better off locking the timing in software as the service connector may have been assigned as a input to control a different function.
Why do we have 2 lots of adjustment then? Would it not be better to have the dizzy fixed in 16deg and allow adjustment solely from ECU? I suppose that's what coil pack systems are about...
 


rvm

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Thanks for sharing this! :bow: :D
 


NIcad7

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Hmmm very interesting and thanks for the how to and info!

I had to repair my dizzy but marked its position so (hopefully) it's in the same position as before I took it apart, but I would like to learn how to check the timing. Best go buy a timing light!
 


Vtec6000

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Why do we have 2 lots of adjustment then? Would it not be better to have the dizzy fixed in 16deg and allow adjustment solely from ECU? I suppose that's what coil pack systems are about...
That is whole point of setting the distributor timing, to sync it with ecu timing!

With the stock ecu you can lock the timing by bridging the 2 pin service connector. With Hondata s300 you use a feature within the software to lock the timing and then adjust your distributor timing. Same process just different way of locking the timing. It's possible also to lock timing with a chipped ecu by bridging the service connector but you need to check with your tuner that the input is still assigned as the service connector input.
 




fez

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I just fitted a new dizzy to my crx, to the same place as the original and it was awfully slow with new one fitted, did the timing and now its better than before. Well worth doing in my eyes.
 


_JT

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Awesome information, thanks! Rep added. Edit: cant rep you again after last time I repped you I guess :eek:
 


Hartsock

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Obd1 cars don't need to bypass the service connector because they don't auto-correct the timing.
That is because OBD1 engines don't have oil pump sensors to read engine's position.
 


Vtec6000

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Obd1 cars don't need to bypass the service connector because they don't auto-correct the timing.
That is because OBD1 engines don't have oil pump sensors to read engine's position.
Yes you do need to bridge the service connector. The ecu is constantly applying changes to the ignition timing at idle, it's part of the idle strategy to maintain a smooth idle. When you bridge the connector you disable this.
 


b16kid

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i was always under the impression that u can advance the timing a few degrees for abit of extra performance.

i know many people who prepare for the dragstrip by throwing in some higher octane fuel and advance the timing abit.
 


Vtec6000

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i was always under the impression that u can advance the timing a few degrees for abit of extra performance.

i know many people who prepare for the dragstrip by throwing in some higher octane fuel and advance the timing abit.
That really depends on the octane of fuel your using and the engine setup itself.

One thing I try emphasize is to not adjust distributor after your car has been mapped.
 


NIcad7

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Got around to checking my timing last weekend after buying a light.

It was slightly off. The crank pulley marks were about 5mm behind the mark, all adjusted and correct now.

Which way is advanced/retarded, infront or behind? With front being towards the front of the car ;)
 


Vtec6000

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Push the distributor towards the firewall to advance timing
 


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