Vacuum lines

[Saladin45]

Hey guys

I've been trying to take down my last issue with my car.

Yesterday I had a MAGNA (Mid Atlantic Buick Grand National Association) member come over and help me out with the car. He owns a hotair vehicle as well and helped me with some tweaking with it to find out what the heck is going on.

Basically, the car stumbles when you hold the gas peddle. If you just accelerate, its fine. If you idle, its fine. But under holding the gas peddle, the car has issues. It stumbles and backfires.

Well, one issue that we've noticed yesterday when we were working on it was this: I have no pressure from my vacuum line going into my fuel pressure regulator. Heck, we don't even know if the fuel pressure regulator even works since there is no vacuum going to it to make it work. What I would like to know is, what in the world could be causing that issue? And does anybody have a diagram or a picture of their own motor's vacuum lines so that I can kinda trace where mine go? I've tried GNTType's site but their vac diagrams don't seem to help me out too much. Its just difficult to trace it all back and the like when you've got most of the hardware in your way of following the lines.

Once I do the test to check the psi on the fuel pressure regulator and check the vacuum and find out whats going on, if I don't find any issues, then my next move would be at the injectors. We're pretty positive that its the injection system. Because we already replaced the ignition module to see if that was an issue, it wasn't. And the MAF was replaced as well, that wasn't an issue. So we're sort of looking here thinking what could it possibly be at this point that is causing the problem? And it just seems that the only thing we haven't really given a hard look at is the fueling system.

And not getting any vacuum to the fpr is a real indication of something going wrong. Am I right?

-Saladin

p.s. Also, I was not getting any codes from the system. And as for my last thread about my cat being off and getting codes, once I put the cat back on, there were no more codes coming from the ECM.

 

[Dwayne]

......something to keep in mind when dealing with a ha maf, just swapping them out and starting the car will most likely not tell you anything. You need to put some miles on the new maf so it and the ecm can "learn" one another. Seen it happen more than once.

Can you blow through your vac./pressure lines with a compressor.....take the vac. block off of the tb and inspect it......I've seen the gasket come apart and go through the lines......simple check......let us know and good luck.

 

[BRAD_PADGETT]

Here is the vacuum setup. Brad

 

[Dwayne]

Some good info right there !

 

[Saladin45]

Brad, thank you.

That is exactly the type of diagram I needed. The other ones I had were sorta faded/hard to read/etc.

-Saladin

 

[Saladin45]

Well, I looked to see what vac line connected to the fpr. And I ran it all the way back to where it hangs a left and breaks off toward the manifold and the boost gauge meter.

Anyway, right there the vacuum is firstly..
1. Dry rotted
2. Bent so bad that it's actually crimped. So I think I've found out why I'm not getting any vacuum there.

Could this vacuum fix be all my issues?

We'll find out tommorow afternoon.

 

[Saladin45]

Well guys

I did a compression test..

1-135
3-125
5-132

2-142
4-140
6-70 (Then after a couple tries it fluatuated and went all the way up to 100 consistently)


But after starting the car after doing the compression test and noticing that the spark plugs were black on the glass itself and putting them back in, the car ran fine. This is after I replaced the vacuum line going to the fuel pressure regulator, etc. Stepped into the gas peddle a little, and the car was fine. Gassed fine, just sounded like a dream.

Thing is, it was putting out white smoke and had the check engine light on again.

But the spark plugs were showing signs of Rich Exhaust. So I think that I've just got to get a tune. Thing is, does a Rich Exhaust cause white smoke?