1994 Blow by Hose, fuel pump, and IAC Valve

[SanCarlosQ45]

Hello all, I am new to the q45 scene but have been watching this forum for some time since we bought the car. It has 152,000 miles and it idles what I would call rough, it seems like it is misfiring where the motor will physically shudder sometimes at idle and more when I rev the car up to 2000 rpm. Also the fuel pump is needing to be replaced, we ordered it so it should be here in a few days. We also bought the almost all of the BG products that Joe carried. We are also going to do the spark plugs later on but that may not be the full cause of the problems. There is no check engine light. We may also be ordering the consult cable from the website blaZt later on.

Since we have boughten the car we have checked and cleaned the MAF sensor and connector, throttle body, and somewhat of the IAC valve. The IAC valve adjustment seems to be way out past the 2.5 turns, maybe close to 5 possibly. Would this mean that there is an air leak of some sort or a vacuum leak that the valve is trying to compensate for maybe? It seems way far out of adjustment. Also would the valve be causing problems at idle as far as rough and that shudder feeling?

Alright, to my question about the blow by hose that connects the metal tupe under the plenum to behind the throttle body. Sorry for no pictures but this tube is bent in a way that it is almost "crimpted" allowing possibly little or no circulation. My question is would this effect the engine in any way as far as idle? Another question I have is would the fuel pump, which we know is going very bad, effect the idle in any way as far as lower fuel pressure than normal.

I have done every search that I could think of and didnt find any concrete info on what I am experiencing. I have tried to Ohm the injectors, but for some reason I cant get a reading, either I am doing it wrong, or my digital multimeter is having issues which is probably the case.

Just on a side note if anyone is selling a 1994 Q45 in the Bay Area and is in the "Nico" please let me know. Not too expensive though.

[Q45tech]

If the IAC manual bypass valve is turned out more than 3 turns it means something in the TB/plate air path is dirty as the IAC is in parallel with TB, creating an air bypass around the TB.

[maxnix]

Test the meter with a known accurate resistor taped to the DVM.

Welcome to NICO.

[SanCarlosQ45]

The throttle body is spotless, I havent seen a cleaner one the last time I checked. There is no dirt or anything.

[Q45tech]

Then what is condition of IAC inside could be that carbon is blocking air flow. We are speaking of microscopic [tiny amounts in wrong place] amounts when +- 2-3 turns of IAC manual valve is the range.

Inside tach is not accurate enough to set idle rpm must use consult to set rpm and read IAC duty cycle.

[SanCarlosQ45]

We will be getting consult possibly soon so we will see. But anyway the inside was just covered in some spots with a minuscule fine layer of black dust and dirt. I didnt see any major blockage, but I will try pulling it off again and cleaning it.

I also had a question, the gasket for the IAC valve covered the bottom cavity of the valve, is this normal? I would have thought that it would have been cast closed, or they did that so it could be accessible to clean. What I am trying to say is that is the gasket supposed to cover the bottom cavity of the IAC valve.

My main question in my first post was if the blow by hose was constricted to the point where not much is allowed to get through would it affect the idle in any way?