EGR Help

[AHall]

Here is a question for the EGR experts. I have a completely stock 1993 240sx fastback that I have owned since 1993. My EGR valve does not cause my engine to stall when I manually open the valve. The valve does open when I rev the engine so it appears to be functioning properly. I have remove, cleaned and tested the EGR valve, BPT and pipe from the exhaust manifold to the EGR valve twice. I have to admit I did not replace the gasket between the EGR valve mounting bracket and the manifold. When I blow air into the pipe, it routes the air properly when the EGR valveis opened or closed. I have taken a clothes hanger and inserted it into the manifold opening where the EGR valve connects but due to the shape and twist of the manifold could only insert it about 6 inches. I did notice what looked like an oil leak at the #1 cylinder opening where the exhaust manifold connects. Upon further inspection the nut was found to be pretty loose. This is odd since I have never removed either manifold.

Does anyone know why the engine is not stalling out? Hopefully it will prove to be the loose manifold nut or gasket. Also should I replace the gaskets on the exhaust manifold or just tighten the nut?

My guess is there is a leak that is not causing enough exhaust gas to be circulated back into the intake to stall the engine or something is plug which is again preventing enough gas from entering the intake.

Thank you for any help.

[compactfean]

If you manually open the egr it should run horrible or die. If nothing changes than the port from the exhaust mani to intake is clogged somewhere. If you have good flow though the tube to the e.m. Than rather the egr valve really isnt opening or the intake manifold itself is plugged up.

[AHall]

It appears that the passage in the intake manifold where the EGR valve connects is blocked. I removed the EGR valve and sprayed in some carbon cleaner and the carbon cleaner overflowed so there is blockage into the manifold. Does anyone know how best to clear this blockage? I tried a clothes hanger but it will no go all the way in the manifold due to twists and turns. Maybe compressed air?

[asoomal]

There is a tutorial, around...doubt I'm allowed to link it.

[AHall]

What do I need to open that plug? I ran a clothes hanger in the EGR hole on manifold and think I got it down to that plug. Now I just need to open that plug. Also do you know how air from this passage feeds into the intake? I guess there are holes that feed the our tubes of the manifold that feed into the combustion chamber.

Thanks for your help.

[asoomal]

Probably a fat allen socket.

Edit: 10mm allen.

[AHall]

I ended up removing the intake manifold and found that the passages for the EGR were completely blocked. The passages were so blocked that I needed to remove not only the two plugs on the end but also the four plugs. Then I took it to the car wash for a thorough cleaning. No wonder the engine would not stall when the EGR valve was manually lifted. The exhaust gas had no chance of getting back to the intake air stream.

After removing the manifold I realized that the oil breather separator on the block, the PCV and the knock sensor probably should be replaced. Is there anything else I should replace while I have this manifold off?

When I removed the manifold, the hose connecting the PCV to the pipe that feeds the manifold tore off. It was soaked with oil. The PCV was leaking oil and the breather separator was covered in dirty oil. I have not replaced any of these parts in th e18 years I have been driving this car. The upper portion of the intake manifold was pretty oily. Perhaps this is the source of the blue smoke when I take off from a stop. The oil from the PCV flowing into the manifold and then into the combustion chamber. I thought it was the valve seals. What do you guys think? I will find out either way once I get it all put back together. I will likely write a detail description of how to remove the intake manifold with pictures since I could not find one that was very detailed.

[compactfean]

I dealt with a problem like that on my sisters car (dodge intrepid). I would also pull the valve cover and make sure the passage way for the pcv and breather is not clogged.also if you want to eliminate the problem you can do a oil catch can setup for the breather and/or pcv system.

[AHall]

Where would this oil catch can go and what is the purpose? Would it eliminate the oil separator breather and pcv?