Shaky idle

Don W.

Don W.

Stab it and steer it
Re: Shaky idle

Well the intake gasket can blow "down" into the valley. Difficult to verify without removing the lower intake. Good time to do the injs if decide to do this. Based on what I read (which is not every post.) it's ignition. You said you changed wires. Whose wires? Separated? Protected from heat? Especially the pas side.

I didn't see if you changed the coil. Might try that if not.

How does it run if you hold the brakes and build some boost?
 
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Pertti K

Member
Re: Shaky idle

Thanks for the encouragement, Jusssi ;-)

Yes I've changed the coil. The wires are these: http://www.rockauto.com/en/moreinfo.php?pk=2768234&cc=1164451&jsn=12 At least it says they have heat protection? Runs ok against brakes. Didn't push that hard though.

Today I checked the pick-up coil: infinite resistance grounded and 790 (kilo?)ohms internally. Also changed the ignition control module while at it. Didn't improve the idle and I'm not able to hit the road at the moment. The distributor cap didn't look too good, only has a few hundred miles on it:
WP_20160529_12_31_02_Pro.jpg


One thing that came into my mind: bad gasoline? It's not old (at least wasn't when the symptoms hit), but it's one possibility.

Thanks for helping me out!
 
Don W.

Don W.

Stab it and steer it
Re: Shaky idle

It's not the cap. What's your plug gap? (To lazy to read back.) :) I rarely change my cap or rotor and don't have any problems. Don't know what to tell you about the wires other than NIEHOFF used be good stuff back in the day.

I -can- tell you, now that you've bought wires, that Magnecor wires absolutely transformed my truck.
 
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Pertti K

Member
Re: Shaky idle

Decided to change the pick-up coil even though it gave ok readings. After disassembling the distributor I noticed that it might very well be the cause for the symptoms, the look was pretty nasty. Also the shield retainer was broken, I noticed earlier that the shield was loose, but I didn't know it wasn't supposed to be that way.

But. After assembly when I started the truck there was no oil pressure. I guess there's two options:

1. I managed to hurt the oil pressure sender wire, or more likely
2. The distributor didn't fall into the oil pump shaft's slot. It's so damn tight place that it's hard to say if it falls in or not, especially when you're doing it for the first time. < Sounds a bit dirty, I know...

But I was thinking, shouldn't the distributor shaft fall into place after starting? Well, I'll have to do it once again tomorrow.
 
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Pertti K

Member
Re: Shaky idle

It seems that I've managed to damage the oil pressure switch, probably when pulling out the distributor, which was a bit stuck. Damn.
 
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Pertti K

Member
Re: Shaky idle

Pretty sure I finally nailed it, at least its idling nicely . Took a while for various reasons - too long a story, but I ended up changing the instrument cluster bulbs to leds, installing the boost gauge and polishing the instrument cluster glass "while I was at it". Plus taking care of 3 other cars, wife, job an such.

It seems that it was the coil inside the distributor after all, even if it measured ok.

BTW, how exact has the timing be? I adjusted it to the last (biggest) slot but when tightening the distributor it changed a bit, being now just at the long edge of the timing indicator, just beside the slot where it should be. So maybe a 1/8" off (late), probably less than 2°. Not a big deal to adjust though, after I've had my practice in it...
 
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Pertti K

Member
Re: Shaky idle

Nope, still does it.

The thread heading is not relevant anymore, biggest problem is the high load low rpm misfiring. I took it for a drive with boost solenoid unplugged. On full throttle at high rpm runs ok, but after upshift starts misfiring.

I took a Tunerpro recording during the ride - anyone wanna take a look?

Edit: There's still on/off idle problems as well. Shaking and while rolling on D it tends to keep the rpm relatily high, varying between 1200-1800 rpm, as someone was pushing the accelerator slightly. This is new symptom, so at least I've achieved something....

Here's the file. A started stationary from a bus stop, accelerated to 55 and sopped on the next bus stop. The values from left to right:
Mass air pressure (1 bar)
Vehicle speed (filtered)
TPS
Oxygen sensorn
RPM

Sieppaa1.PNG
 
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IGottaSy

IGottaSy

Active member
Re: Shaky idle

Pertti K said:
Thanks for the encouragement, Jusssi ;-)

Yes I've changed the coil. The wires are these: http://www.rockauto.com/en/moreinfo.php?pk=2768234&cc=1164451&jsn=12 At least it says they have heat protection? Runs ok against brakes. Didn't push that hard though.

Today I checked the pick-up coil: infinite resistance grounded and 790 (kilo?)ohms internally. Also changed the ignition control module while at it. Didn't improve the idle and I'm not able to hit the road at the moment. The distributor cap didn't look too good, only has a few hundred miles on it:
WP_20160529_12_31_02_Pro.jpg


One thing that came into my mind: bad gasoline? It's not old (at least wasn't when the symptoms hit), but it's one possibility.

Thanks for helping me out!
Click to expand...

By the looks of this,
You have your distributor clocked wrong. You aren't getting full advance.
 
liquidswords88

liquidswords88

I pity da fool
Re: Shaky idle

My ty has been running very poor as well. Turbo spool was instant and wanted to over boost instantly. It made no sense as it had no power to go with the boost. After tons of research I found out that retarted timing will cause quick spool and over boost issues. If there is not enough advance in the timing it creates excess heat in the exhaust, which in turn creates more pressure to turn the turbine in the turbo. I triple check the timing and the balancer mark and they were both spot on. With the timing plug connected I was only getting like 5-8 degrees advance? So I left the plug connected and started to experiment with timing settings. As of now I have the timing set at 35degrees advance at idle with the plug connected? The truck runs good and has loads of power. my over boost is gone as well. None of this makes sense to me. So if I was you I would check your timing with the plug connected and see what your advance is at. From what I have read it should be 15-20 degrees advance at idle. I could not find a concrete answer as to what it should be, I would think it would be the same for all the trucks? You would need a timing light that has adjustable timing advance built into the gun.
 
Don W.

Don W.

Stab it and steer it
Re: Shaky idle

IGottaSy said:
By the looks of this,
You have your distributor clocked wrong. You aren't getting full advance.
Click to expand...

Huh? From a picture of the inside of a cap? Allowing for the fact that the module wires won't always reach you can't "clock" a dist wrong. If timing is correct (with a damper that has not slipped) and plug wires are in the correct order the dist can be "clocked" anywhere. Advance is determined by the ECM.

There is a "stock" location ("clock" position) but that is irrelevant to how the engine actually runs.

All that being said I'm reminded of an issue I had some years ago where a rebuilt dist had the pickup coil out of phase causing the dist to "fire" with the rotor nowhere near the terminals in the cap. I'll see if I can find the pictures or dredge up the post that showed this.

Edit: Link added

Go here and then down to post #12

http://www.syty.net/forums/showthread.php?t=67715&highlight=reluctor
 
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Pertti K

Member
Re: Shaky idle

Changed new plugs with .028 gap and put 2/3 tank fresh gasoline. Maybe a slight improvement, but not much.

What bugs me, that it seems to be a bit of a on/off thing, not perfect at any point, but sometimes better, sometimes worse.

The high idle seems to be connected with the AC operation. Didn't remember it would increase RPM that much though.
 
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Pertti K

Member
Re: Shaky idle

I don't have a adjustable timing light, but I'd say it has 20ish degrees advance with the wire plugged. The Protuner data tells the same story, here's Spar adv. rel. to TDC and ref pulse curves from the pull that I did.
Sieppaa2.PNG
 
IGottaSy

IGottaSy

Active member
Re: Shaky idle

Don W. said:
Huh? From a picture of the inside of a cap? Allowing for the fact that the module wires won't always reach you can't "clock" a dist wrong. If timing is correct (with a damper that has not slipped) and plug wires are in the correct order the dist can be "clocked" anywhere. Advance is determined by the ECM.

There is a "stock" location ("clock" position) but that is irrelevant to how the engine actually runs.

All that being said I'm reminded of an issue I had some years ago where a rebuilt dist had the pickup coil out of phase causing the dist to "fire" with the rotor nowhere near the terminals in the cap. I'll see if I can find the pictures or dredge up the post that showed this.

Edit: Link added

Go here and then down to post #12

http://www.syty.net/forums/showthread.php?t=67715&highlight=reluctor
Click to expand...

Yes, what I see from this picture...

Distributor is turned counter clockwise so far that the ECM is having to correct advance over and over once it has reached the limit. He can verify this if he checks for arcing spark off the wires and an unstable timing mark.
It will most likely arc off as this has the same effect of a large plug gap.

Think about it a little. I bet if he turns the distributor clockwise a couple degrees less than a cylinder, it will run better because there will be more advance.. I am no mechanic and am still learning but this makes sense to me.
If no difference, then just move it back. It cheaper than throwing parts at it.
 
Last edited:
IGottaSy

IGottaSy

Active member
Re: Shaky idle

:tup:

The ECM only corrects up to 14 degrees if I read it right.

liquidswords88 said:
My ty has been running very poor as well. Turbo spool was instant and wanted to over boost instantly. It made no sense as it had no power to go with the boost. After tons of research I found out that retarted timing will cause quick spool and over boost issues. If there is not enough advance in the timing it creates excess heat in the exhaust, which in turn creates more pressure to turn the turbine in the turbo. I triple check the timing and the balancer mark and they were both spot on. With the timing plug connected I was only getting like 5-8 degrees advance? So I left the plug connected and started to experiment with timing settings. As of now I have the timing set at 35degrees advance at idle with the plug connected? The truck runs good and has loads of power. my over boost is gone as well. None of this makes sense to me. So if I was you I would check your timing with the plug connected and see what your advance is at. From what I have read it should be 15-20 degrees advance at idle. I could not find a concrete answer as to what it should be, I would think it would be the same for all the trucks? You would need a timing light that has adjustable timing advance built into the gun.
Click to expand...
 
Don W.

Don W.

Stab it and steer it
Re: Shaky idle

OK, first go here and look at where the "wear" is on this rotor.

http://www.syty.net/forums/showthread.php?t=94747&highlight=dist+rotor

It's been my belief for quite some time that the dist cap itself is slightly out of phase to the dist. Look at the cap in the first link I posted. The go to the above link and look at my modified rotor and the "matching" cap.

See the difference in where it's burnt? I am probably the only guy here running this, I admit, weird rotor. But if nothing else I feel better...:rotf:

To your point. The dist rotates clockwise. Rotating, moving, it clockwise will -retard- the spark. There is NO advance built into the dist. Vac or centrifugal. Once the timing is set to 0 with the wire disconnected and a damper that has not slipped, reconnect the wire and the ECM handles advance from there. It's my understanding that once this is done the dist only provides a "TDC" reference to the ECM.

This is why I contend that it's not the cap. Something else in the dist maybe but not the cap. Unless, of course, it's cracked and we don't see it.

For my other rant on this you can go here.

http://www.syty.net/forums/showthread.php?t=103678&highlight=dist+rotor
 
Don W.

Don W.

Stab it and steer it
Re: Shaky idle

It depends on what chip you have. Stock = 2 bar. Modified = probably 3 bar but could still be 2 bar. Sportmachines on this site sells the 3 bar.
 
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