In June 2002, we bought this 1994 Suburban with about 184,000 miles on the odometer.  Now the previous owner had the valve stem seals changed and for the most part it ran pretty good.  But it always had a fairly rich and rough idle.  Even after I gave it a thorough tune-up, replaced the catalytic converter, installed a

Dynomax cat-back exhaust system, and a K&N air cleaner; it always had a rich and rough idle. Quite often, my wife would complain about the "exhaust" smell at idle. I tried advancing the timing, but the knock sensor would pull it right back out. At about 200,000 miles, I installed a new distributor, replaced the intake gaskets and rebuilt the TBI unit, including new injectors and fuel pressure regulator. This made no difference. Over the next few thousand miles, I replaced every sensor and emissions component you can think of, but it still ran the same. I even tried installing a 1" TBI spacer from S&P, but this made no difference. However, I will say that the spacer made a noticable difference when moving, especially at WOT. I would say the estimated HP improvement was realized. The truck was getting 18-20 mph(hwy). At about 219,000 miles, I installed a new fuel pump and strainer.

Well, at about 236,750 miles, the original 350 finally blew a head gasket. So I put a brand new GM crate engine (stock replacement) in the truck. This was in June 2004, two years after we purchased the truck. As you can see in the picture below, the tired old truck delivered its replacement engine. But I'll tell you, she just about didn't make it to the house. At the same time, I installed Edelbrock's Pro-Flo MPFI conversion system, Edelbrock TES (headers), a new radiator, water pump, t-stat, clutch fan, belt and hoses. Because the Edelbrock system requires TPI type fuel pressure, I installed another new fuel pump and strainer. The Edelbrock system ran great for about the first 5,000 miles. However, it soon returned to the same old rich and rough idle. I consulted with Edelbrock technical support and we tried a number of different things, but to no avail. I have invested too much to give up at this point. So what to do next?

My 1991 Firebird GTA was just about to hit 200,000 miles (original engine), so I decided to park it and rebuild the engine, suspension, etc. sometime in the future. After coming to the conclusion that the neither the TBI nor the Edelbrock system was making the grade, I decided to swap the TPI unit from the GTA over to the truck. So these web pages are my documentation of the process. Follow along as the process unfolds.
 

Out with the old engine and TBI, new GM crate engine ...

(Click Here for a Full Description of the Crate Engine, GM P/N 12520270)

Out with the old Edelbrock system and in with the TPI system ...

The finished product, the TPI installed in my 1994 Suburban ...

CLICK HERE to see a MAF TPI Conversion on a K1500 Pick-Up Truck

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Please visit my webpage for my 1981 Camaro Z28 at www.edgesz28.com.