70 series 1hz engine starts fine but hard shutoff

[hzj77inCA]

Hi
I have a 98 hzj 77 70 series. 169 k miles. Noticed that engine shutoff is getting more harsh. Shuts off quickly but hear several cylinders go off ‘bang bang bang’ after shutoff, especially when I shutoff shortly after starting. If I run car for 15 min or so and drive around only a small shake on shutoff. I have already changed the rubber fuel lines to continental lines no leaks, and checked the fuel primer and changed fuel filter. I also checked the fuel tank vent valve and it works. I guess next is the shutoff solenoid or injector? Any thoughts
Thank you
Govin

 

[Eurasiaoverland]

Is this something that has always happened or a recent development?

Fuel line problems would manifest in starting issues, stumbling or smoke, I don't think harsh shutoff would be a symptom. Similarly with the solenoid - it's a switch so it either works or it doesn't. How do injectors cause a rough shut-down?

Normally a noisy shutdown indicates damaged engine mounts, or something else mechanically loose on the exterior of the engine (e.g. an exhaust heatshield).

If the engine has had the ACSD (cold start device) removed from the IP, or never had one (I think only JDM 1HZs got the ACSD) then cold starts will be rougher, and hence cold shutdowns may be rougher.

 

[hzj77inCA]

Is this something that has always happened or a recent development?

Fuel line problems would manifest in starting issues, stumbling or smoke, I don't think harsh shutoff would be a symptom. Similarly with the solenoid - it's a switch so it either works or it doesn't. How do injectors cause a rough shut-down?

Normally a noisy shutdown indicates damaged engine mounts, or something else mechanically loose on the exterior of the engine (e.g. an exhaust heatshield).

If the engine has had the ACSD (cold start device) removed from the IP, or never had one (I think only JDM 1HZs got the ACSD) then cold starts will be rougher, and hence cold shutdowns may be rougher.

Thank you for your thoughts.
Now that you mention it, I did get the old engine mounts changed and this started soon after. I’ll check them. I don’t have an ascd that I know of.