Bravada saga continues!

[Rob LaMoy]

Well for any of you who have been here a while, you know the issues I've had with my tow vehicle. It's a '94 Olds Bravada with the 4.3 multi port Vortec.

Last year, while towing home from a tourney, going up a huge mountain I blew the orginal motor when I lost a cylinder. Drove the remainder of the 70 miles home anyway. That's another victory to Duralube! LOL Knocking like crazy the whole way and only 30 mph on most hills with no power, but it DID drive home.



Anyhow, I had the motor replaced with a new, crated motor that I have specially ported, and polished, with a new exhaust system, air filter and chip so that I put out 242 HP. Great for towing. However, the problems did NOT go away. The new engine was a long block but naturally some things had to be swapped over from the old engine. Most of them were NEW also though.



Here's what's been replaced.



EGR valve 3 times!

O2 sensors, both of them

pick up coil

ignition module

distributor

ENGINE with plugs, wires, etc all being new

starter

alternator

battery

heater core

water pump

thermostat

coolant temp sensor

MAP sensor

fuel filter



But she still ran hot, rich, and carboned up. I had had it in to two or three different shops a half different times to find the problem. This last time I had had it! With only 5k miles on a brand new engine I was not going to let this bad boy blow. So I brough it back and told them to do a vaccum test on it since it wasn't throwing any codes. Vaccum leaks will not usually show up on diagnostic.



TADAAAH!!!!

Massive fuel leak in the intake manifold! Which of course was part of the old engine. So I take it home and remove the top manifold plenum. There in a pool of gas was a leaking fuel presssure regulator.......$49! It had been loading up the engine all along causing ALL these problems. A $49 part has cost me about $5,000 over 3 years!



So I have a new one coming tomorrow, along with new exhaust manifolds, brakes and the paint to repaint the truck, and then other then the tranny, everything is new. She's a 2004-2005 truck trapped in a 1994 body design! LOL I'll drive the damn thing until the wheels fall off now!



If anyone ever has problems with the 4.3 Vortecs, feel free to contact me. I am INTIMATELY acquainted with them and have likely encountered the problem you have and can help you fix it. I'm just glad I finally found the problem.

 

[Larry Harp]

I had a 94 GMC Safari van with that engine. At 198K when I sold it (I was sorry I didn't get to see go over to 200K)it was solid as a rock inside...HOWEVER I had replaced dang near everything that was bolted to it. 2 or 3 alternators, a starter, a couple of water pumps, fuel pump, 3 wiper motors (the only vechile I've ever replaced even one wiper motor on), countless EGR valves and O2 sensors plus relays and sensors in the tranny a couple of times too. I think the A/C compresser and the fuel injection were the only major things I didn't have trouble with.

GMC=Gotta Mechinic Comin'



Harpo

 

[TOMMY RICH]

You need to find a good garage if they couldn't find the problem the first time. Been there and still doin' it Rob

Just replaced the motor in my 94 Siverado 350 with a new crate motor. With headers and a few other upgrades...I really need to change out to an adjustable regulator. It allows you to move the pressure manually to fine tune it.

Go to CFMtechnologies.com and check it out. I think they carry them for the 4.3.

When you start adding mod's...the fuel pressure needs to be adjusted so it isn't starving for fuel

I also replaced the stock intake manifold with an Edelbrock...big improvement

 

[Dan J.]

Hopefully this will get you 100%!! You've dang well earned it!! Just keep looking towards the future. It gets brighter every day!

 

[TOMMY RICH]

Found out somethin' also about so called "aftermarket" EGR's that you pick up at AZ and AA are NOT the same as OEM!

Found that out the hard way with this motor

 

[Jim B]

Rob i had the same thing happen to my 93 sonoma. It sounds like you have the 4.3 cpi injected. One other thing you may want to think about replacing while you have it apart is the fuel injector spider assy. Thats the main injector and tubes that feed each cyl. The tubes have a tendancy to crack over time and when the fuel leaks thru the cracks it will run super rich.



btw you can get way more then 240hp out of that motor if you really wanted to. I dynoed my 93 at 285hp to the rear wheels( 334 at the crank), all it takes is money. The cpi really responds well to mods. I used to anger a lot of guys with 5.0l mustangs at the strip. The truck would run low 13's all day. The looks on thier faces with thier v8 stang on the bottle got smoked by a little pickup with a v6 without nitrous or a supercharger. Priceless.

 

[Staci Matheis]

Is it true that Jim B and Pat Goff are actually the same person posting under two different names?

 

[byron cooley]

Contact any reputable dealer. All parts of your CPI system are now covered for 10 years or 200,000 miles. GM had too many fail, when that happens the emissions go sky-high. On the early models, with the injectors in the center unit, they are now replacing it with a complete unit with injectors at the end of each tube. You can tell by wires out to the end of the tubes. This recall covers all Vortec 4.3's. You might not have gotten a notice as it is a vollintary recall. Oh yea -- On the EGR -- Take it off and cut a small circle of stainless sceen to cover the inlet port of the EGR valve and bolt it back down. You only bought those valves because a small chunk of carbon stuck the pintle open. The ECM then thinks that it needs to add fuel and runs rich, rough idle, and stalling. With the valve off any carbon will drop out by manually opening the valve.

 

[Staci Matheis]

(I was refering to straight line, speed demon sorta stuff!)

 

[Bruce Freeman]

Byron I have to guess that you know that is a $10,000 fine if caught? Very rare I admit but still not cheap

BF

 

[byron cooley]

What is a $10,000 fine??? I didn't say to block the EGR's flow, only to put a screen over the inlet hole. We do it at our shop all the time. Your EGR still gets plenty of exhaust flow, just no carbon chunks. It's been our Vortec,s digital EGR fix for years. Not 1 has ever had another problem after. Also after some more research, the recall covers vehicles sold for California for 200,000mi or 10 years. Check to see what the situation is in your state. I'm not sure why it varies from state to state. If GM knows they made junk, any and all should be covered.