I Need Some Serious Timing Help Here!maybe a misfire?
Posted 07 January 2012 - 04:14 PM
The car drives beautifully at speeds over 35 mph, on the highway, it still cruises without incident at 75 mph. It's only at idle or at very low speeds like cruising up to a stoplight that it shudders. I'm guessing a misfire more than timing? Is it true you can't adjust the timing on these engines? You can only verify the timing? The only thing I neglected to do was check each plug wire for continuity from end-to-end (I will do that when I see his car again), I'm thinking maybe with removing the boots from the plugs, the wire broke internally on one of the wires, thereby killing power to one of the cylinders.
Posted 07 January 2012 - 08:04 PM
I always screw in spark plugs with my fingers only, until I am very certain it's threaded properly.
Also I have run into more than one defective cap and or rotor, might try putting the old ones back in.
Posted 07 January 2012 - 10:05 PM
I did have the rotor facing forward in the distributor, toward the front of the car. Why is there a small bolt at the 1:00 position on the distributor? It looks like it allows the distributor to rotate slightly left/right. Swapping plugs from one cylinder to another wouldn't help since I have no idea which one is at fault. The whole engine shakes. The CEL is not illuminated either, so there is no code to tell me which it is.
Unfortunately, I tossed the old cap & rotor. I've never had this happen to me before...
Posted 08 January 2012 - 06:29 AM
Yes that is a leftover from '88 and earlier 240s where the timing was set by the position of the distributor. You can put a timing light on it, rotate the distributor, and you will not see the slightest change in the ignition timing.
Why is there a small bolt at the 1:00 position on the distributor? It looks like it allows the distributor to rotate slightly left/right.
Timing in '89+ 240s is handled by the ignition computer (ICU), which has an crank position sensor located above the flywheel/drive plate (aka speed sensor), load signal from the fuel computer (ECU), and also input from the throttle position switch (TPS) and temp sensor (ECT).
As I mentioned before, you may be able to determine which one is at fault by unplugging the injectors one at a time at idle, where if you find that one injector/cylinder dropping out has less of an effect than the others, that would indicate the fault is with that cylinder. You should check to see if there are any stored codes even if the CEL stays off, for reference: http://www.brickboar...ineOBDCodes.htm
Swapping plugs from one cylinder to another wouldn't help since I have no idea which one is at fault. The whole engine shakes. The CEL is not illuminated either, so there is no code to tell me which it is.
Posted 09 January 2012 - 07:29 PM
Former: 89 744 GLE 16V, 90 745 GLE 16V, 95 964, 94 854 Turbo, 01 S40 1.9T, 99 C70 HPT, 01 S60 T5, 07 VW GTI
Current: 98 V70 GLT - 155k, 02 Motor, 16T, ARD (DD), 97 854 GLT - 2xxk,(Backup)
Posted 11 January 2012 - 11:29 PM
Posted 15 January 2012 - 07:45 PM
I always keep a set of used tune up parts in my trunk. whenever I change something, I throw the worse used one away.
(the first 3 are mine,heh,heh.) 525,000 Volvo miles put on 10 bricks
Posted 16 January 2012 - 12:18 PM
Note a much easier way to do that: unplug the injectors one at a time, same effect as pulling the wire off, without the risk of serious shock.
To check for a bad plug or wire, you could disconnect one at a time - the bad one will not make any difference, BE CAREFUL and use a really thick wad of rags to grip the plug - you do not want to see how muck a shock will hurt!
Posted 17 January 2012 - 04:42 AM
Posted 17 January 2012 - 12:29 PM