1990 Q45 vibrating at 2000 rpm and shutting down when cold

[Q451990owner]

The car has been sitting for 12 years, the tank has corroded, fuel pump corroded, I replaced both, 2 fuel injectors were bad #1 and #8 , I replaced those since they were accessible.
The car was driving great after there , but a slight vibration at 1500-2000 rpm.
I cleaned the mass airflow sensor and the intake as described in this forum.
I bought redline, that thing is strong. Within one day, the car started and when cold now it shuts down, and the car feels like its missing . Check engine light is not on, however, I noticed that it turned on for a brief few seconds now and then off. (the light)
I found out the guy who helped me did not change the original filter.... So I changed it. And brown stained gas came out... Full of powder like rust...
I changed filter 2 times now. But the car will turn off when in low RPM sometimes, mostly when cold, and is vibrating at 2000 rpm.
Are my injectors clogged due to the redline breaking loose the gunk and rust?
Why is the car shutting down now? Sometimes in the middle of driving ...

[Skibane]

Well - Most fuel delivery problems (i.e., engine starving for gas) won't set the check engine light...

A bad injector will often set the check engine light, since it causes a misfire in that particular cylinder.

If you still have the last fuel filter you replaced, you might cut it open and see how much crud is inside it. If there's a lot, that would be a clue that there's still crud in the fuel system that's plugging your filter.

Also, some trouble codes don't turn on the check engine light - so it might not hurt to get the car scanned to see if there are any codes at all.

[Q451990owner]

I cut open the second filter, it was not very dirty, and replacing it with a 3rd one did nor resolve the issue of shutting off when cold. Also I noticed that when cruising at 65, if I floor the gas to kick down, it chokes. That is if I kick down one gear it's fine, but 2 gears it chokes. By the way the transmission is new, as it was replaced by dealer 3,000 miles ago, and I replaced the fluids and filter and put a cooler .
I'm suspecting a bad mass airflow sensor, or a dirty one , even though I cleaned it prior to putting redline. Could redline have caused all this damage? Does it create more carbon deposits on the airflow sensor?

[SanCarlosQ45]

So I think the problem might be that your bad fuel filter + dirty lines may have stressed out the Fuel pump control unit due to increased. Did you check the control unit when you replaced the pump? If you get a second, check the connector to see if its burnt, you may also want to open it up to see if the circuit board is also. There should be a guide on q45.org on checking and fixing this.

A quick check would be to bypass the FPCU with an aligator clip, again shown on q45.org.

I wonder if your vibration maybe a transmission mount and exhaust hanger issue, but without feeling it its hard to tell.