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I do as the FSM says and use the paper clip to short TE1 and E1 and the engine at 800 RPM warned up. But the ignition does not come even close to the TDC mark and there is not enough adjustment to get it there.
It seems that the auto spark advance is not stopped by the computer to allow me to set timing at 10 degrees Before TDC.
The engine have been giving me problem with lack of power.
Checked Timing belt and is perfect. New spark plugs and wires, Changed ignition coil and igniter. New injectors. checked pump fuel pressure and on specs.
Checked distributor and seems good. Scoped the signals for the distributor G1 G2 and NE and they seem very consistent an reasonable. Gap maybe a littl on the high side for the NE coil. I have not been able to get a good typical signal with the Picoscope on the ignition coil primary voltage.
I did not notice that but will check tomorrow morning. I am doing plenty wrong, three months working on a neighbors car
What I noticed since I started this saga is that if a raise very slowly RPM's when it get to around 1700 1900 start to cycle RPM's up and down.
Today on a test run felt better but not smooth enough and not enough power and came again with CEL 12 "no NE signal".
I scoped with the Picoscope 2205A and see lots of garbage at the distributor. But when I rigged the distributor on the bench driven by a drill gave very clear signals for NE, G1 and G2. but when I scope the Signal from the ECM to the ignitor expecting a clear square wave signal I get lots of "NOISE"
I order a distributor to swap it, but hate to be beaten like this and changing parts just on a hint.
Printed lots of pages tonight and plan to use the "Service Hints" to see of I can advance.
Thanks to all for the input.
Attached are some of the signals I got today with a short description on the area on the name.
Some of the values on the vertical axis may not be correct because I qam at the same time learning to use PicoScope and dod not master yeat the set ups
Thanks for your time and advice
yes, I did remove it but I make a mark before moving and had it on TDC Exactly. Also tried one tooth forward and other backwards, no help.
The distributor give fairly good scope patterns on the bench but I am not sure it is the same when connected.
I had check all cables for ground and continuity/resistance for the distributor signals to the ECM and all checked OK.
Also replace now injectors while rechecking Timing Belt
What get me is the weir to me cycling or jumping RPM's if raised smoothly from 1700 up to around 2000. Then it seems to smooth out but still no good power for a 6 cylinder engine with compression on the 6 cylinder above 155 psi. in my opinion
I do as the FSM says and use the paper clip to short TE1 and E1 and the engine at 800 RPM warned up. But the ignition does not come even close to the TDC mark and there is not enough adjustment to get it there.
It seems that the auto spark advance is not stopped by the computer to allow me to set timing at 10 degrees Before TDC.
...
To set base timing you need.
Engine coolant temp sensor = warm (this takes the ECU out of the warm up table, and closes the idle air valve)
Throttle position sensor closed, THA below 1volt.
Throttle position sensor IDLE (IDL) closed.
RPM in the 600-800 range.
And TE(TE1) grounded.
..
In this state you should have a steady flashing check engine light and can set the base idle. If you have satisfied all of these conditions and are not able to get the idle in the zero to ten degree range by turning the distributor you've identified a non-electrical issue.
Two things come to mind at this point. First is a stretched timing belt, and second is someone milled the block-height (head and or block) to low.
..
You're still getting the NE signal failure code which means one of two things, you've missed a loose/dirty connection a bad wire or the ignitor is failing (well make it three, you could also have a failure in the ECU like a dry/broke solder joint or other components).
When you jump the terminals, does the idle drop some and the CEL flash?
Yes, I do not why but now it does now and I re-set timming to 10 degrees BTDC.Then my timing light INNOVA burnt up. I had never used it in ten plus years since I bought it !!!!!
Changed ECU with and used one and run better. Now no more "No NE signal to ECU" but brake light comes on a off briefly
Still loack of power.
Planning on figuring out how to Picoscope at The ECU injector's voltage, Air FLow Sensor wave forms and O2 sensors behavior since I do not have access to OBD-1 Data scanners.
Yes, I did take it out 5 times and checked signals at the bench with a Picoscope and the wave forms where very consistent and ohms were all within specs
Since that I purchased a new distributor and works much better and no more CEL 12 (No EN signal to ECU.
Replaced also with an used computer and run even better with no more CEL 12 so far.
But now brake light comes on and off briefly with no reason at all in my view. What the Hell!!.
Double check the TPS idle switch that @Co_94_PU referred to. The IDLE switch must be closed, or the ECU will still be trying to manage timing, and you'll get nowhere. You may need to adjust the TPS before you can do the timing.
These old computers are starting to fail from years of heat and vibration. I believe they can be rebuilt with new capacitors ect. A common issue with setting timing on these is the harmonic balancer (aka crank pulley). The inner portion comes loose from the outer portion that the timing marks are on and makes it impossible to set the timing. To check remove all the accessory belts and see if you can spin the outer portion by hand. Mine on my 88 3vz was so loose I pulled it right off with my hand.
These old computers are starting to fail from years of heat and vibration. I believe they can be rebuilt with new capacitors ect. A common issue with setting timing on these is the harmonic balancer (aka crank pulley). The inner portion comes loose from the outer portion that the timing marks are on and makes it impossible to set the timing. To check remove all the accessory belts and see if you can spin the outer portion by hand. Mine on my 88 3vz was so loose I pulled it right off with my hand.
I think the distributor bushings are a much more common issue but I guess that rubber ring might have a lot to do with the local climate?
It’s not so much the climate as it is the age of the rubber. Most of these parts are 30 years old. What do you mean by rubber bushing on the distributor?
02-12-2020, 10:33 AM
