Fermin4

Help badly needed: Pictures attached;
I got a 2205A Picoscope and took the six cylinder's waveform but I cannot make any sense of them
Attached are with Channel B the screen copies of the six cilinders
Please HELP. I am lost !!!

The car seems to start on the second try when is cold. Runs poorly until it warms up completely and then quits on low rpm missing badly
Once warm, it start m missing even more and slowly drops rpm until it dies.
Hard to get it started after very hot and propane injection makes no difference
I had the fuel pump set almost permanent for more than two weeks and pressure 39psi with regulator, 43-45 without it.

Had new distributor (sometimes not NE signal)but no MIL light now running for two hours
Very little power and missing somehow, cannot determine the cause.
New IGNITER, coils, plugs, TPS(set as per Fact. Manual)
New T Belt 8 years ago, checked it a month ago and seems perfect an on time.
Smoked the Intake manifold and never found a trace of smoke out.
Knock sensor new but mounted on the engine lift hook.
Runs the same whether I have the clip on time adjustment or not
Idle adjustment screw does not seem to respond very well to find a sweet spot
Timing was check with vacuum gauge on 19-20 Hg
Find months working

all taken with Hantek T-25 on chanel B I have also the *.psdata files.





and cannot find the problem

TechA

Brother, your timebase is incorrectly set.....simply put....you're zoomed too far out.

Detail and repetition are 2 things to remember when trying to capture an accurate sample on a lab scope. I am not familiar with the picoscope software and only work exclusively with "crap on" lab scopes. But, accurately setting your time base (how much time you have the sample coming across the screen aka repetition) and the voltage scaling (the detail) will get you the waveform you're looking for.

Also, when on the secondary side of an ignition circuit, you can "trigger" the initial waveform on that circuit and it will essentially hold that waveform in place on screen to watch it better (inspect firing line of the plug, dwell time, etc...), otherwise you watch every cylinders waveform and things can get confusing.

This can also be done on the primary side of the system by monitoring coil amperage while triggering off of a corresponding fuel injector (when applicable) for firing order and cylinder identification....

Good luck my good sir....you got this

Fermin4

TechA: Thanks a lot. learning slowly here. Very much appreciate the suggestion and now I get decent waveform
Once more. Thanks for you comment.
The car was sold yesterday, I could not find out what was the problem and the owner also gave up
1995 3VZE when for $1,000 solid engine mechanically but a control problem I could not find. Missing real bad when warms up, good running when cold.
I kept taking voltages until the cows came home and did not find out the problem.Enhanced test mode gave DTC 13.
Thanks to all that illuminated my path along. I will continue learning the Pic 2205A good stuff.