1995 GMC Safari CPI

Hello gentlemen! My CPI in my 95 safari has been giving me trouble and I’m going to replace it again.

my real question is can I eliminate my EGR and reduce carbon buildup inside of the engine by doing so?

and any other tips that I could do to improve longevity with the engine are welcome and much appreciated. Thanks in advance!

 

If the only problem that you are having is carbon getting stuck in the egr valve, remove the valve and clean the chunks of carbon out. With the valve off, start the engine and hold idle at about 2000 rpm to blow out loose carbon. Then install an egr valve gasket with a screen to prevent carbon from sticking the egr valve open. Standard Motor Products #VG57. Eventually, if the screen plugs, you'll get at check engine lite and a code 32 so you would have to clean the screen, but you won't have the rough idle and stalling. Another option is , if you have a scan tool, command the egr valve wide open while revving engine to blow out carbon.

 

I’m going to change the intake gaskets tomorrow as well as the Plenum and change the spider again. I’ll check the EGR which was just replaced recently. I keep having a number three plug fouling (Middle spark plug driver side) and I’m guessing it’s due to faulty intake gaskets leaking coolant into that cylinder. This vehicle sat for nine years before I put it back into service. It has been performing well until the last few months. I’m hoping it’s not a head gasket. Not sure how to check that beyond doing a leak down. Any insight you can offer would be great!

 

There is no possible way coolant is getting into the center cylinder from a bad intake gasket. You should save your time and do a leak down test on that cylinder.

I wrenched on 100s of 4.3s of that vintage when I was in college. You pretty much have to clean the egr with every oil change.

Before you replace the spider, put a fuel pressure gauge on it and see if it holds. Otherwise you're wasting time and money.

 

Did the fuel pressure gauge thing couple of days ago. It’s not holding. figure I have a bad regulator, stuck poppit or something worse. Replaced the fuel pump and filter already as well. Changed the filter four times at this point. There has been some debris in the filter. The spider and regulator combo are under warranty because I did it within the last few months.

 

How do you suggest cleaning the EGR? I want to be effective in doing it as I am planning to replace my spider tomorrow. Thanks

 

I would pinch the return line and then run the fuel pressure test again. You'll check the regulator and rule out the spider at the same time. If you decide to pull the plenum you can pressurize the fuel system and check for leaks.

 

Brake parts cleaner and wire brushes. Is the egr valve below the throttle blade?

 

This photo is when I took it apart to change the EGR along with the last time I changed the spider.

On the front of the block/intake. So I would say yes below the throttlebody/MAF. I am super illiterate when it comes to this vehicle. But I do love it! So I’m looking for input from the guys who have worked on them and know the idiosyncrasies of this set up. Thanks! The EGR is electrically driven as opposed to vacuum. The van is an early 95 so it is pretty much everything 94 related

 

Do you think it would benefit me somehow to eliminate the EGR? I’m willing to go the route of a new flash prom to reflect eliminating the EGR if that makes sense…

I don’t have a catalytic converter on the vehicle any longer. I have changed the O2 sensor as well but then I had a Hydro lock last week which may have affected the new O2 sensor?

 

Anyone have thoughts about me going this route?

 

Honestly these were some of the worst vehicles GM made. The vortec/balance shaft 4.3s were not reliable. Fuel pumps, spiders, near constant egr or 02 sensor codes. The corrected distributor cap which nearly guaranteed a crossfire/misfire.. the engine itself had head gasket and cracking issues, and once in awhile the split pin crank would snap in half. Factor in the crappy 4l60e, the transfer case hop and wheel bearings...

Sell it. You won't regret it.

 

Think I found my problems, disassembled it today and found distributor cap issue as well as intake gasket leaks. In addition, regulator on the spider was leaking. Should be good as new tomorrow!

 

I’m going to change every sensor, wire harness, small items and distributor. Hope to get 10 more years out of this gem!

Then put a 350 in it with a carburetor and normal distributor and no more computers!

 

I would have only pulled the lower intake if necessary. It was common for those blocks to crack down the center of the lifter valley and start knocking 100 miles or so after the intake was replaced.. GM tried to say that they found surface conditioning disk debris or shop rag pieces embedded in the bearings or that the manifold wasn't torqued correctly. Eventually, they admitted that the blocks had thin castings. Anytime that I had to do a lower intake on that era 4.3, I would loosen the intake bolts in reverse sequence in 4-5 passes. That's one of the only intake manifolds that I torqued. Of the 100's of intake gaskets that I did in my 23 years as a GM technician, those were the only ones that I ever had problems with. Like 436'd Skylark said, there's no way for coolant to enter #3 because of an intake gasket. If cylinder 3 did have coolant in it, it will still get coolant in it after replacing the intake gasket. Are you sure that it wasn't fuel? If a poppet sticks open, it will fill the cylinder with fuel. I've also seen regulators shoot fuel right down cylinder #6. After you pulled the upper intake, you should have reattached the fuel lines and pulled the poppets out of the intake and cycled the key. You would have seen if a poppet or the regulator was leaking.

 

I did loosen the bolts in the reverse pattern as you suggested. Will take care when reinstalling lower intake as you pointed out what to look for. Thanks. I do have A long time GM Tech working with me on this now.

And, the regulator portion of the spider was definitely leaking.