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These engine are interference engine and if the timing chain comes undone it will damage the intake or exhaust valves
I did a head gasket replacement 2 months ago and changed the timing chain before putting the head back on, unfortunately didn’t clamp the chain link
Strongly enough since a month ago while driving I heard a noise from the engine compartment and the car stopped dead, after many days of troubleshooting I found out the chain had come undone, but miraculously no damage to the chain or sprockets only the chain’s link was undone yet still attached but the chain was completely off, it took a while but I managed to get the chain back on, clamped it like a son of a gun and set the crankshaft pulley’s timing mark with the timing cover’s mark and the adjusted the camshaft sprocket’s timing mark so it also matched the camshaft’s timing mark, rotated it 2 turns and all marks coincide, happy about luck put everything back and tried to start the engine, it seemed it was trying but not catching on, so I removed the plastic cover
And sprayed starting fluid into TB housing and cranked it again, after the 3rd try, it started but very rough and would die if I took my foot from accelerator
But it was backfiring (seemed like it) or was loud and trembling, I have checked all the essentials, spark at the cap, new plugs, checked fuel pump and ran it directly but shorting fuses, and changed FPR, also checked IAC, CPS, TBH, TPS, leaks and so on … no luck, now I am back to the timing issue, is it possible the tooth on flywheels have been damaged so the cps can’t correctly set the ignition timing or the camshaft hall effect sensor is not recognizing where the TDC on 1st cylinder is, or maybe the camshaft’s are 180 degrees off( they are at TDC but one turn off) the car ran fine after the headgasket replacement, so it was set correctly, I get a ENGINE LIGHT but for the love of god could not use the diagnostic socket to flash the code(grounded a cable by attaching to ground/earth location on the cylinder block next to thermostat) and turn the engine to on position and plugging the other end of cable to pin 6 on the top for .5 to 4 sec
Nothing happens (do I need to put a 47k resistor in parallel with cable?) Anyway there must be a way that you can check to see if you have the timing chain correctly (I read on a Volvo BB that
RPM sensor gets its signal from a slotted wheel riveted to the drive plate. For LH2.4 engines there are 58 slots with room for 60 slots, there being two hole voids. To check the ring gear installation for proper timing, remove the starter and position the engine on TDC for number one cylinder. There are 58 holes on the timing ring, with a void of two holes (room for 60 holes, total). The void will be at the bottom of the starter opening if the ring gear is installed properly.
Now I know that for Saab 900,
Mounted on the crankshaft is a slotted ring with 58 ribs. Of inductive type, the sensor is mounted on the wall of the engine crankcase. The distance between the slotted ring and the sensor is 0.4-1.3 mm and it is not adjustable.
The sensor acts as a small alternator and generates a sine-wave a.c. voltage. The voltage and frequency signals from the crankshaft position sensor vary with engine speed. Sensor input at idling speed is 5 - 10 V a.c., 870 Hz, and at 2500 rpm it is 15 - 20 V a.c., 2400 Hz. The frequency is of interest to the control module as it is directly proportional to engine speed. By measuring the frequency of this current, the control module can determine engine rpm.
Two ribs are missing on the slotted ring after the 58th rib. When the first rib passes the sensor, the control module knows that the crankshaft is 117° before top dead centre (BTDC) for cylinder No. 1. By measuring the two missing ribs the control module can determine the position of the crankshaft.
The control module mainly uses engine speed and the crankshaft position as a basis for calculating ignition timing, injection time, injection duration and for idle speed control.
Would I be able to check for proper timing by looking at the starter opening, any suggestion or comments are welcome, I love my Saab but this car is driving me crazy, need to get it going ASAP so please help
posted by 64.136.26...
, Sat, 18 Jun 2005 15:20:34, Sun, 19 Jun 2005 08:14:01
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