420A Problem with revs and sound of Hydraulic Lifters

[Sttanis]

Hi, I have had these problems for some time now, the engine is rectified, it is a 420a from 1995
The revolutions are always around 2000 revolutions without me stepping on the accelerator or anything, and in my head it makes the sound of the hydraulic lifters but they are new, I have tried changing the type of oil to see if it was because of that but nothing , on the highway the car loses power and it is difficult for it to accelerate it happens to me when I demand a little more or I turn it up a little more revs than normal
If someone can help me because i dont know what to do, Thank you from Spain

 

[motomattx]

Maybe its an exhaust manifold to cylinder head leak?

 

[dustyboner]

if your idle is at 2000 rpms, its probably one of these things:

• a vacuum leak
• throttle body isn't closing all the way
• malfunctioning Idle air control motor

for you lifters:

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and for the acceleration problem, i would start by changing out the fuel filter.
after that if you still have the problem, check the fuel pressure

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if you need a copy of the factory service manual, you can get it HERE

 

[BLACK'98DSM]

Sounds like a good time to upgrade to PT lifters to me

 

[Sttanis]

Thank you , im gonna check it