Where is the standard engine tune up information listed in the factory manuals?
I am looking for the plug gap, the distributor timing, and the correct RPM setting for checking the timing with the timing light.
Also the idle speed too.
I have read my engine manual for my '91 4.2 liter engine and do not find it there.
jimm1009

If you are referring to a 420 116.xxx engine then the plug gap should be .8mm or .032 in. The timing is handled by the EZL ignition unit and the crank shaft position sensor at the left rear of the engine. It is not adjustable. There is a setting for the distributor but it is done by setting the engine to TDC and then setting the distributor so the rotor points to a mark on the dist housing. You can use a timing light to check the EZL function for advance but I don't think I have ever seen any specs.

Paul

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84 500 SEL (307,xxx miles)

Well that certainly clears up the "why" in why can't I find the specs.
I was going to set the distributor with the timing light but that won't be the case.

#1 TDC and point directly to the hash mark on the top of the distributor case.

Got it.

Thanks so much. Off I go to the garage again.

jimm1009

For reference:

Timing at:
Cranking and idle - w/o vacuum 3-7 BTDC, w/vac. 10-14 BTDC
@ 3500 RPM - w/o vac. 28-32 BTDC, w/vac. 41-45 BTDC

Thank You Frank R.

I put the engine back on TDC and put the center of the rotor on the hash mark or scribe mark on the distributor housing.

It started up cold just fine so the road test is next but not today as we are getting a bad rainstorm pretty soon.
jimm1009

Well I drove it about 1.5 miles today at 30 MPH or less.
It seems to have a slight flutter sound in the valve train.
Now the camshafts & rocker arms are new and the compensators (hydraulic lifters) are used but I tested them by pushing down on them with a large hammer handle as demonstrated in the manual.
All passed and I went through the valve clearance checks with the special tool and adjusted the shim caps as required. Many of them are brand new and some are used with no distinguishable wear. The heads were rebuilt about 5,000 miles ago and I had them vacuum checked to make sure of the seats being tight.
I also fine tuned the cams per the manual.
My left cam is right on 22 degrees and my right cam is on 19 degrees rather than 20 as that is as close as I could get with the offset keys.
Right side is set tighter to begin with when the valve train and chains are new so it will wear towards the 22 degree mark per the manual.
This is not a terrible flutter but still noticeable and mostly when cold.
I am sure it needs to wear in some but I am wondering if a lifter is not as good as it should be somewhere in there.
jimm1009

1991 US 420SEL

I drove it to work today. A nice, easy 15 mile run at varying speeds up to 60 MPH.
The flutter that I feel was the same as before I tore the engine down for chains, head work, etc.
I am wondering if my EZL is going bad and causing a loss of power during acceleration. '91 N.A. 420SEL
I simply don't have enough experience on this engine model. I may have to take it to an experienced pro but hate to spend that money after all this $ & sweat over the last 8 months.
Would extra hard drive shaft coupling discs cause a feeling similar to a u-joint being loosed on an older US truck or car?
I examined them very, very well while installed but they are hard as rock. This is not associated with the "flutter" of the engine but a secondary note taken.
jimm1009

How does it idle? Is it smooth or do you hear/feel a miss? If it idles good and the valves are not ticking then your valve train is fine. EZL generally won't cause a problem like you are describing, They usually work or don't work. I have seen one that didn't advance correctly, but the car ran fine, just drank gas. If it has a poor idle, than look for that problem first.

The flex disk are all hard. If you feel a slight vibration at about 40 MPH while accelerating, then you may be able to get rid of that by loosening the slip joint nut close to the center support. Now this is the hard part, put the car on the ground and roll it back and forth a couple of times. Put the parking break on and the trans in park. Now raise the car on one side at the center (front to rear) just enough that you can slide under and tighten the slip joint nut. Be sure to put something under the car so it can't fall on you as the drive shaft tries to turn. There is a torque spec for that nut but I just use what ever I can find and snug it up but don't crank down on it a lot.

Works for me.

Paul

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84 500 SEL (307,xxx miles)

I will try that. Thanks for the other tips too.
jimm1009

I have not been able to check vacuum system yet but thought that I would report a new finding.
In a heavy accelleration onto the interstate and engaging the kickdown switch under the gas pedal the vehicl jumps in and out of gear from one to the next. Now what I mean by this is when you step on hit hard it down shifts one gear as it should. It then jumps to the next higher gear and then drops back again. It repeats this cycle about 4 times until a speed of about 65 MPH is acheived. I don't want to go any faster than that due to the engine only having 65 miles on it since I put it back together and the 2007 Michelins are dry rotted to apoint of concern for me.
I did fill it up with 93 oct. Chevron with techtron fuel and added one container of fuel injector cleaner yesterday mid day. The other fuel was 89 oct.
I will investigate vacuum soon but am planning on changing out all the lines as I am going to add the vacuum adjust system for my Euro Bosch headlights too when that package is received so some of the problem may go away through atrition.
jimm1009