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914World.com _ 914World Garage _ Only firing on 2 cylinders
Posted by: JB 914 Nov 21 2004, 03:21 PM
Fired up the car today and it was running really rough. Skline came over and pulled the wires off 1 and 2 and there was no change. Its got hydraulic lifters, could it be they are all collapsed on the one side? It gets gas, and its got spark. I guess the next step would be compression check and pull the vavle cover to see if they are functioning? Any ideas???
Posted by: DrifterJay Nov 21 2004, 03:25 PM
damn...your engine is bad too....... <_<
Posted by: DrifterJay Nov 21 2004, 03:26 PM
at least you got the chevy though...
Posted by: jimtab Nov 21 2004, 03:51 PM
This may sound stupid but pull the valve cover off of the side that's not firing. A VW bug I used to have had exactly the same symptoms and the cause was the bolts had sheared and the rockers were laying in the valve cover, extracted the bolts and re did the job...all better.
Posted by: Series9 Nov 21 2004, 04:13 PM
1. Check compression on all cylinders.
2. Use a timing light to verify spark on all cylinders.
3. Check the timing.
Your problem will probably reveal itself in one of these steps.
Posted by: Aaron Cox Nov 21 2004, 05:02 PM
that sucks.....
bummer....was just at joe sharps house, hope it sorts out 
Posted by: LvSteveH Nov 21 2004, 05:22 PM
If you are running carbs, check the idle jets, they get plugged easily, and can render the cylinder dead until the main jets come on at 3000 rpm, and even then it might be a bit lean without the extra fuel.
Posted by: skline Nov 21 2004, 06:38 PM
I would pull the valve cover off that side and fire it up and make sure your valves are opening. It was working fine before you pulled that cover off earlier, I would bet the whole story will become clear with the cover off. If you were not having that party today, I would have helped you and we could have figured it out in no time. If you do get to it today, let me know what you find? I am still betting either lifters not pumped up or the valve train is not hooked up right. The push rods may be laying in there not even hooked up.
Posted by: JB 914 Nov 21 2004, 07:13 PM
i popped off the valve cover and it doesn't appear the valves are moving as much as you said they should Scott. i left it off, so, maybe you can stop by on Monday and take a look.
I'm guessing it's the lifters. Anyone got some hydraulic lifters they wanna sell?
Posted by: Demick Nov 21 2004, 08:28 PM
Could be a dropped intake valve seat. Mine exhibited similar simptoms when that happened. If the intake valve seat drops and holds the valve open, then it can affect all of the other cylinders in a very wierd way. I could pull both plug wires from one side of the engine, and both fuel injector wires from the other side of the engine, and it still ran as crappy as when they were all plugged in. Hope it's not that, but a compression test will immediately tell you.
Demick
Posted by: Dave_Darling Nov 21 2004, 08:36 PM
Check all of the wires in the engine bay first. Injector plugs, injector ground wires, and so on. That is probably the easiest way to lose 2 cylinders.
--DD
Posted by: qa1142 Nov 21 2004, 09:01 PM
If you are running stock FI the grounds run in pairs side to side. You likely have bank one ground NFG.
Check it.
(Learned this from Brad Mayuer!)
Posted by: ChrisReale Nov 21 2004, 09:28 PM
Ask Jake Raby!
Sorry couldn't resist
Posted by: qa1142 Nov 21 2004, 09:45 PM
Check your grounds
Posted by: JB 914 Nov 21 2004, 10:06 PM
running carbs and they are getting fuel
Posted by: Dave_Darling Nov 21 2004, 10:10 PM
Then they're not getting something else, I bet....
You can check to see if they're getting spark by taking a spare plug and taping it so the threaded area (or outer electrode) is against a ground. Then you can watch the plug while someone cranks the starter.
BTW, major compression losses will show up as an uneven pattern in the sound of the starter motor. I found my last dropped valve seat by noticing that the starter went "RR-RR-RR-..-RR-RR-RR-.."
--DD
Posted by: Aaron Cox Nov 21 2004, 10:13 PM
check for spark on those two cyls...
then compare that rockers motion with the other like one (exh or intake) on the other side
Posted by: JB 914 Nov 21 2004, 10:17 PM
check for spark on those two cyls...then compare that rockers motion with the other like one (exh or intake) on the other side
gonna try that monday if i get time before sundown got dark, so, i closed shop. Cold too!!
Posted by: JB 914 Nov 21 2004, 10:19 PM
check for spark on those two cyls...then compare that rockers motion with the other like one (exh or intake) on the other side
gonna try that monday if i get time before sundown got dark, so, i closed shop. Cold too!!
BTW, got plenty of spark and gas new plug wires, new points, new pulgs
Posted by: Aaron Cox Nov 21 2004, 10:45 PM
ok..so its strictly mechanical then.... cam - lifter - pushrod - rocker - valve - valve seat pick your poison
Posted by: skline Nov 21 2004, 11:35 PM
The odds of having 2 bad valve seats on the same head which was just done by Rimco less than 1000 miles ago is highly unlikely. We will find out what it is tomorrow and post the results. I am still betting its lifters, either collapsed or broken. It pops on the cylinders when the RPM's go up. See who guesses the resolve. Winner gets a Boobie prize. 
Posted by: Aaron Cox Nov 21 2004, 11:38 PM
loose rockers or bad lifters is my guess...
hows it goin scott?
Posted by: skline Nov 21 2004, 11:57 PM
I aint touching mine again till Friday. Jared said he was going to come out and help me. I have to cut the mounts for the exhaust (Hangers) and then remove the muffler system to get the transmission out so I can make the modification that Renegade said. Should have it out and done in about 3 or 4 hours. Then its time to adjust the clutch and see if it moves on its own. While I am at it, I am going to figure out some way of making the exhaust removable without cutting the hangers again.
Posted by: JB 914 Nov 22 2004, 12:25 AM
I'm gonna pretend it's the fuel injection problem even though i have Carbs.
let me live in DENIAL at least one more night
Posted by: DrifterJay Nov 22 2004, 01:27 AM
yeah me 2...hehe...
Posted by: DJsRepS Nov 22 2004, 04:35 AM
Pull coil wire and turn engin over to hear if it has a dead compression, cylinder if in doupt pull the plugs and use tool. Assumeing it has enough to fire all 4 and you have fuel inj then check the trigger points with ohm meter or pull the dist and clean and inspect and Ohm out with meter anyway. As for your valve motion the best one can do without rebuild is valve adjustment and or pull pushrods inspect for bent. (Slim chance of bent) Also check all grounds at block under intake!!
Posted by: DJsRepS Nov 22 2004, 04:37 AM
Scratch the trigger points I didnt read page 2. Good luck.
Posted by: JB 914 Nov 22 2004, 07:36 PM
compression seem pretty low on both cylinders. didn't have time to check the 'good' side
so, it looks like rings 
less than 1500 miles. i guess they never seated.
looks like i'm pulling it out and tearing it down again. 
anyone up for a rebuilding party? i'll smoke some good pork w/ home made BBQ sauce 
Posted by: Aaron Cox Nov 22 2004, 07:38 PM
so, it looks like rings
less than 1500 miles. i guess they never seated.
looks like i'm pulling it out and tearing it down again.
anyone up for a rebuilding party? i'll smoke some good pork w/ home made BBQ sauce
that sucks! you sure the valves are closing all the way?
Posted by: JB 914 Nov 22 2004, 07:44 PM
so, it looks like rings
:headbang: :headbang: :headbang: less than 1500 miles. i guess they never seated.
looks like i'm pulling it out and tearing it down again.
anyone up for a rebuilding party? i'll smoke some good pork w/ home made BBQ sauce
that sucks! you sure the valves are closing all the way?
compression held and did not go down, so, i don't think it's valves. it was 75 on one and about 85 on the other one.
i pulled off both valve and they were moving about the same on both sides, so, i'm ruling out lifters.
that compression seems way too low. i thought it should be over 100? i'm not sure what is acceptable.
Posted by: ematulac Nov 23 2004, 09:29 AM
I had the same exact problem when my car sat in storage for a few years.
Remove the top of the carb and check the float and the needle valve.
What I found in mine was that the little wire spring that goes on the end of the needle valve had corroded to gunk and was keeping the needle valve from opening. So basically, the carb was getting gas but the gas wasn't flowing through the carb.
Hope that helps. 
Posted by: skline Nov 23 2004, 09:38 AM
The gas is flowing through the carb, you can open the throttle plates while its running and watch the fuel flow in, he removed the plugs and they were wet so he is going to pick up some new plugs and try it again. When we pulled the heads off last time I remember noticing there was a lot of deck height (Space between the top of the piston and the head) so I am thinking that is why the compression is so low. If it were mine, I would take the cylinders to Rimco and have about 1/4 inch or so shaved off the top and then replace the rings and lap them in again and run it. I am sure he could take off at leasst 1/4 inch off the top and even still have too much deck height. As I recall, there was about 1/2 inch or so. The guy he bought this engine kit from was building it for a plane so the low compression would be what the guy was shooting for. I would bet the other 2 cylinders are about the same compression.
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