Engine idle question (SATURDAY UPDATE)

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Topic Public / General Discussion / Engine idle question (SATURDAY UPDATE) (1126 hits)

By Chaznsc Date 2012-07-20 02:44 Edited 2012-07-21 16:51

Yesterday I took her out for a spin and it took a little longer for her to warm up, or in other words, to stop stumbling. Eventually smoothed out but it got me to fretting. Tonight I pulled the SP wires one at a time and only cylinders 1 and 3 made a noticeable drop in the idle when disconnected. (assuming those are the two closest to the driver) the other two really didn't make much of a difference. She's running fairly smoothly, but I'm just a little concerned. It's a single port engine, and is stock except for the exhaust which I think is called a bazooka style.

Anyhow, it's been a long time since I've fooled with a vdub motor and wanted to get some feedback.

Chaz

By Chaznsc Date 2012-07-20 02:56

I should also note the SP wires are zip tied together on each side. I seem to recall this being a bad idea?

By Brad H 1498 Date 2012-07-20 02:59

Check your valve adjustment, .006 COLD. set you points at .016, spark plugs at .028. If one side is running rough or seems to be lazy spray some carb cleaner around the intake where it meets the head to check for a vacumn leak. If it speeds up when sprayed you have a leak. FIX IT IMMEDIATLY or you risk melting pistons, heads etc.
Spray along the bottom of hte intake too, somtimes they rust out between the intake tube and the heat riser tube.

The drivers side cylinders are 3/4, 3 being closest to the front of the car. 1/2 on passenger side, 1 being closest to front of car.

FRONT
/\
3 1
4 2

The wires are zip tied on my motor too and I run a coil pack. If they are in good shape don't worry about it.

brad

By Gary F 2793 Date 2012-07-20 03:02

I had a similar problem and it turned out the distributer wasn't always sending fire to the plugs. had a bad distributer. changed it out and now it idles fine.

By Chaznsc Date 2012-07-20 03:05

I'm getting spark to each cylinder, it's just that two don't seem to care LOL. I have corrected my numbering bungle.

By Jeffrey P 655 Date 2012-07-20 13:08

As Brad has suggested check your valves and check for the vacuum leak. Where the intake seals to the head is a notorious spot for leaking.

By Chaznsc Date 2012-07-20 23:40

I'm checking the valves in the am. What's the chance of these two cylinders having burnt valves? My brains working overtime.

By Jeffrey P 655 Date 2012-07-21 03:06

Is the exhaust on that side cold?

By Chaznsc Date 2012-07-21 03:21

Neither side is cold, but I seem to have only cyls 1 and 3 working fully so neither would be cold correct? Strange it ran so well when I got it home, then this.

By Chaznsc Date 2012-07-21 15:18 Edited 2012-07-21 16:50

Ok, opened the valve covers and all the valves were tight. I only thought to measure number 4 and the .004 wouldnt fit. I TRIPLE checked i had the TDC right for number one and started the adjustment. Got everything adjusted back to 006 and it starts of course.

Sprayed carb cleaner on the manifold connection at the head and got no rev or gurgle. Sprayed the body of the carb and the exhaust spit out some blue smoke. Did it twice, then did it after taking it out and it didn't do it again. I do, however, notice there's condensation on the manifold connection at the carb (??).

However, somethings still not right. I think some of the car shake (previos post) is coming from the motor. Sitting still with the hill brake on, if I rev the engine and hold it (not sure rpm but not real high by any means) I hear some very faint popping, not even sure I call it a pop, but it's a noise like that. And I wouldn't say the engine is stumbling but it's like every so many revolutions it has to cough or something. Sorry for the laymans description and like I said its pretty faint, it's not a backfire noise, not even close. It could just be a header type of thing based on backpressure, etc.

I pulled the plugs, they look very good. Gaps weren't perfect (tight) but I corrected
And put back in.

I have noticed in pulling the plugs of the distributor, that 1 and 3 make the most difference at idle. 2 and 4 make a slight difference, but it's noticeably less than their adjacent cousins.

The car shakes whole driving it, not really bad but noticeable, not sure if that's engine or something else. And it could be I'm now hyper sensitive about the car.

Anyhow, if anyone has any additional ideas I would appreciate, I'm pretty bummed out.

chaz

By Jeffrey P 655 Date 2012-07-21 17:42

Popping can mean a lean mixture of exhaust leak. Try backing out the mixture screw 1/8th turn. Make note of where it is so you can return it if it doesn't help. You want to make sure you make one change at a time.

When I asked if the exhaust was cold I mean right where it exits the head. A non-firing cylinder will be cold to the touch.

I would also check all your exhaust connections for tightness.

Lastly, the shake could be due to bad mounts. Check all three.

One last suggestion. Start it and run it when its dark out...as dark as possible. Look for arcing along the plug wires or near the cap.

By Chaznsc Date 2012-07-21 19:00

Jeff,
Thanks for the reply. Engines mounted tight. The heads are hot on all four ports. I do have however a notocible leake where the manifold meets the heat riser tubes. The one on the drivers side is much more pronounced. It's got a good looking gasket on it, looks like it needs something with some fluff to seal it off if that makes any sense, I guess to out it another way, the connection isn't "flat" and it's a seepage, and I'd say a good one. Not sure if that makes any difference at all.

I'll get someplace dark tonight.

Chaz

By andrew s 1965 Date 2012-07-22 02:09

check the compression
i had new pistons rings and jugs put in 1600 sigle port because the valves were over tightened by previouse owner.
compression was bad in two cyl.
not sure what compression needed is.
i let my mech do this but i am told it is simple.

By Jeffrey P 655 Date 2012-07-22 03:14

They make thicker composite gaskets for that heat rider. It can also be "tweaked" to make it fit better.

By Sandsurfer Date 2012-07-22 12:39

The heat riser will not affect the way the engine idles unless the temps outside are in the low 30's. I run the stock carb on my Baja without heatrisers and only have an issue when it is 30 degrees or colder.

Jerry....

Topic Public / General Discussion / Engine idle question (SATURDAY UPDATE) (1126 hits)


Login Home Account Buggy ID Forum Registry DBA Shop Clubs Gallery History How To Members Maps Calendar Email Us	DBA Forum - Not logged in Forum DBA Home Help Search Chat Topic Public / General Discussion / Engine idle question (SATURDAY UPDATE) (1126 hits) By Chaznsc Date 2012-07-20 02:44 Edited 2012-07-21 16:51 Yesterday I took her out for a spin and it took a little longer for her to warm up, or in other words, to stop stumbling. Eventually smoothed out but it got me to fretting. Tonight I pulled the SP wires one at a time and only cylinders 1 and 3 made a noticeable drop in the idle when disconnected. (assuming those are the two closest to the driver) the other two really didn't make much of a difference. She's running fairly smoothly, but I'm just a little concerned. It's a single port engine, and is stock except for the exhaust which I think is called a bazooka style. Anyhow, it's been a long time since I've fooled with a vdub motor and wanted to get some feedback. Chaz By Chaznsc Date 2012-07-20 02:56 I should also note the SP wires are zip tied together on each side. I seem to recall this being a bad idea? By Brad H 1498 Date 2012-07-20 02:59 Check your valve adjustment, .006 COLD. set you points at .016, spark plugs at .028. If one side is running rough or seems to be lazy spray some carb cleaner around the intake where it meets the head to check for a vacumn leak. If it speeds up when sprayed you have a leak. FIX IT IMMEDIATLY or you risk melting pistons, heads etc. Spray along the bottom of hte intake too, somtimes they rust out between the intake tube and the heat riser tube. The drivers side cylinders are 3/4, 3 being closest to the front of the car. 1/2 on passenger side, 1 being closest to front of car. FRONT /\ 3 1 4 2 The wires are zip tied on my motor too and I run a coil pack. If they are in good shape don't worry about it. brad By Gary F 2793 Date 2012-07-20 03:02 I had a similar problem and it turned out the distributer wasn't always sending fire to the plugs. had a bad distributer. changed it out and now it idles fine. By Chaznsc Date 2012-07-20 03:05 I'm getting spark to each cylinder, it's just that two don't seem to care LOL. I have corrected my numbering bungle. By Jeffrey P 655 Date 2012-07-20 13:08 As Brad has suggested check your valves and check for the vacuum leak. Where the intake seals to the head is a notorious spot for leaking. By Chaznsc Date 2012-07-20 23:40 I'm checking the valves in the am. What's the chance of these two cylinders having burnt valves? My brains working overtime. By Jeffrey P 655 Date 2012-07-21 03:06 Is the exhaust on that side cold? By Chaznsc Date 2012-07-21 03:21 Neither side is cold, but I seem to have only cyls 1 and 3 working fully so neither would be cold correct? Strange it ran so well when I got it home, then this. By Chaznsc Date 2012-07-21 15:18 Edited 2012-07-21 16:50 Ok, opened the valve covers and all the valves were tight. I only thought to measure number 4 and the .004 wouldnt fit. I TRIPLE checked i had the TDC right for number one and started the adjustment. Got everything adjusted back to 006 and it starts of course. Sprayed carb cleaner on the manifold connection at the head and got no rev or gurgle. Sprayed the body of the carb and the exhaust spit out some blue smoke. Did it twice, then did it after taking it out and it didn't do it again. I do, however, notice there's condensation on the manifold connection at the carb (??). However, somethings still not right. I think some of the car shake (previos post) is coming from the motor. Sitting still with the hill brake on, if I rev the engine and hold it (not sure rpm but not real high by any means) I hear some very faint popping, not even sure I call it a pop, but it's a noise like that. And I wouldn't say the engine is stumbling but it's like every so many revolutions it has to cough or something. Sorry for the laymans description and like I said its pretty faint, it's not a backfire noise, not even close. It could just be a header type of thing based on backpressure, etc. I pulled the plugs, they look very good. Gaps weren't perfect (tight) but I corrected And put back in. I have noticed in pulling the plugs of the distributor, that 1 and 3 make the most difference at idle. 2 and 4 make a slight difference, but it's noticeably less than their adjacent cousins. The car shakes whole driving it, not really bad but noticeable, not sure if that's engine or something else. And it could be I'm now hyper sensitive about the car. Anyhow, if anyone has any additional ideas I would appreciate, I'm pretty bummed out. chaz By Jeffrey P 655 Date 2012-07-21 17:42 Popping can mean a lean mixture of exhaust leak. Try backing out the mixture screw 1/8th turn. Make note of where it is so you can return it if it doesn't help. You want to make sure you make one change at a time. When I asked if the exhaust was cold I mean right where it exits the head. A non-firing cylinder will be cold to the touch. I would also check all your exhaust connections for tightness. Lastly, the shake could be due to bad mounts. Check all three. One last suggestion. Start it and run it when its dark out...as dark as possible. Look for arcing along the plug wires or near the cap. By Chaznsc Date 2012-07-21 19:00 Jeff, Thanks for the reply. Engines mounted tight. The heads are hot on all four ports. I do have however a notocible leake where the manifold meets the heat riser tubes. The one on the drivers side is much more pronounced. It's got a good looking gasket on it, looks like it needs something with some fluff to seal it off if that makes any sense, I guess to out it another way, the connection isn't "flat" and it's a seepage, and I'd say a good one. Not sure if that makes any difference at all. I'll get someplace dark tonight. Chaz By andrew s 1965 Date 2012-07-22 02:09 check the compression i had new pistons rings and jugs put in 1600 sigle port because the valves were over tightened by previouse owner. compression was bad in two cyl. not sure what compression needed is. i let my mech do this but i am told it is simple. By Jeffrey P 655 Date 2012-07-22 03:14 They make thicker composite gaskets for that heat rider. It can also be "tweaked" to make it fit better. By Sandsurfer Date 2012-07-22 12:39 The heat riser will not affect the way the engine idles unless the temps outside are in the low 30's. I run the stock carb on my Baja without heatrisers and only have an issue when it is 30 degrees or colder. Jerry.... Topic Public / General Discussion / Engine idle question (SATURDAY UPDATE) (1126 hits) Powered by mwForum 2.10.2 © 1999-2007 Markus Wichitill Help \| About DBA \| Terms of Use \| Kwiki Home \| Logout Content Copyright (C) 2006 Dune Buggy Archives.