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Hi.
Just started my motor for the first time after a rebuild. It started and seems to run OK. After breaking in the cam I took it out for a little spin. I noticed the header on #1 cylinder pipe did not get as hot as the rest. I took an IR thermometer and if the rest are 600 deg F. #1 is 200 deg at best. I disconnected the fan for a bit thinking it may be cooling the pipe better than the rest but it made no differnce. I have rechecked the valve clearance and injector spray, injector grounds, injector pulse with an Oscope, spark, leakdown etc. Changed plug, wire, rotor, cap, timing is 15 btdc . What could cause this and not be effecting the other 3 cylinders,???. Any ideas would be welcome. I can not figure it out and am out of things to try.
Greg Bodner
1970 1800E
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Just wondering, but did you determine the cause of this? I've been most curious.
--
Justin 66 122E, 71 145S
Read vclassics!
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posted by
someone claiming to be Viper1800E
on
Wed Jun 25 13:56 CST 2003 [ RELATED]
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If anyone has an IR thermometer out there can you check/shoot your exhaust temp on your exhaust manifold at each pipe port at all cylinders and tell me what you get at idle and 3K RPM. If you have a header installed it would be best. I have tried everything in the free world to get the #1 cylinder to read as high as the rest. I am gettng number like 250, 600, 600, 650 deg. F ( 1,2,3,4).
Greg B.
1970 1800E
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Me too. I am still to hurt/weak to do the wrenching from the surgery last Thursday. I had deviated septum, sinus, tonsil, adenoids, UPPP junk done/removed for sleep apnea problems. Bending over is still out the question for now. Still have some spints in nose and my Doctor would kill me. .. I was mad I had to get this done and had to leave the rebuilt engine cylinder 1 problem open ended.
I sure I will get to it in the next to few weeks. Thanks for the interest and I will post with more info when I get back to it.
Greg B.
1970 1800E
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Greg, I'm confused... you say it seems to run fine, but from the temp anomoly, I would think #1 isn't firing at all. ???
Got any color on the plugs yet?
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Seems to run somewhat fine under load or when driving. It would not idle very well or at all until I bumped it to 1100 rpm. Plug seemed rich when driven and not firing when idle or low RPM like it was trying but making no power.
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Adjust the knob on the ECU for best idle and see if that doesn't improve matters. It'll take a while for the valve train to settle down, so #1 may be just a tad further out of whack than the other three cyls. Find which way the knob wants to adjust, give it a click or two, reduce idle, click, reduce, etc. until you have the best of both.
But actually, now that it's run a little while, I'd start off with a head retorque before doing anything. Work from the center bolts outwards alternating sides -- just barely break one loose, then torque it to 69 ft lbs, then move onto the next one. Reinstall the rockers and adjust to .018" lash. All this is done cold.
Did we cover the adjustment technique that actually gets all the valves the same yet? (I put many hours of back pain into testing this...)
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Phil Thanks,
I did retorque the head. I will recheck the adjustments. If you have the procedure I would appreciated it. Did I see it on VClassics??? I still am going to do a cold and hot compression and leakdown again at my frieds suggestion. I am not ruling out a sticking valve or something like that. I have Parker head with double valve springs .. Only has 300 miles on it since rebuild. I did I think ruled out the spark by swapping wires, hooking the spark (gap jump type) checker, new plugs, cap, rotor, reverified wires on cap etc. all seemed normal. Ruled out fuel by pulling rail and examining spray pattern into 4 containers for volume and spray (all equal), swapped the all new injectors around and looked at the pulses from the computer with a osciloscope (all the same) at the injector connectors, trigger points would cause an other cylinder to be bad (2&3, 1&4 pairs out of points I think) , measured injector resistance and verified grounds are good to all..
Greg
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You could try the 'shade tree' compression check. Just pull the coil wire and crank the engine round and round. If the starter labors evenly over each compression then there isn't a compression problem on an isolated cylinder. If it strains over 2 or 3 and not on 1 or 2 then look more deeply into things.
When setting the valves you can ensure you are setting on the cam surface opposite the lobe by turning the engine until a valve compresses, then setting the 'mirror image' one. For example, if #1 is open, set #8. If # 2 is open, set #7. If you look at a cam out of an engine you can see that the 'mirror' lobe is directly opposite, 180 degrees removed.
I once checked the compression on my Dad's old farm truck - a '51 Ford F350 with an untold number of miles on the tired old straight 6 engine. Lowest was 25 psi, highest was 35 (cold, cranked with the throttle open). The starter would just sort of spin round and round unimpeded until the engine wheezed into life.
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Greg, we do have an article in the archive, but here's the short version:
Turn motor (in the direction it runs, of course) until you see an exhaust valve just start to go down. Adjust the intake on the same cyl. Repeat for the other intakes.
Turn until you see an intake valve just start to come up from the fully open position. Adjust the exhaust on that cyl. Repeat for the other exhausts.
The reason this works best is that there is a certain amount of flex throughout the valve train, including the rocker shaft. While the Haynes technique of "adjust #1 when #8 is fully down, adjust #2 when #7 is fully down, etc." is theoretically perfect, it doesn't factor in what force neighboring springs are having on the shaft, and it's significant when we're trying to adjust to an accuracy greater than .001" -- the valves at the ends of the shaft always turn out looser than the ones in the middle.
Works for any motor with 2 valves per cyl and non-variable valve timing, BTW, not just Volvos.
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Sounds like something I can try. Thanks to all respondies. I may not get to try the things I would like for a week or so as I will be out of commission due to nose and throat surgery Thursday. What is a good timing range to shoot for?? Book says 10 btdc but it seemed to like 15 to 17 for idle. I know this is unrelated. I have the VV61 cam.
Thanks,
Greg
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