[PACTKE]

Here is one for the books!!

I have a 95 chevy suburban, 134k, 5.7L, 4x4, TBI. Engine is clean, no leaks(lower rear main only). 2 years ago the water cooled manifold nipple broke and the intake had to be removed to fix(replace). While intake was off, the EGR valve was remove and location was cleaned of built up carbon. Replaced intake with new intake gaskets and used Permatex sealant on the front and rear between the manifold and engine(per instructions). Installed Distributer (had marked before removal) by lining up marks, and had the engine timed by "ear and power braking" by old gm mechanic. Broke the coolant sensor (front of engine) and replaced with (autozone)part still a high idle, took to dealer service and the scan showed a -35 degree teperature, replaced with $22 GM part (no problem). Engine idled at 550 in drive and about 700 in neutral. No power problems and had a mpg of 15-17 on the highway. There isn't any smoke and had no detonation problems. Oil changed every 2500 since owning at 91K.

NOW the problem ... Engine developed a small miss of about 50 rpm miss. Has gotten progressively worse. I did replace a pcv to TBI HOSE and got a perfect idle for 3 days. Now the rpms in drive are at 500 and idles with every 5 seconds a 1-250 rpm loss and will eventually die. It does the same at a red light,turn etc. It also sounds like pinging-detonation while cold (below 150 degrees) and accelerating. Also has surged at times at red light and does die out. The plugs are ac delco and the wires are delphi - 6 months old.

What have I done... Taken out the TBI after market spacer and have put in a new IAC. Pull of the hose to the MAP sensor and got a distinct change in the engine, cut out, and had a lot of vacume. Removed the TPS connector and got a check engine/service light...removed neg terminal and reset computer. THERE ARE NO CODES SHOWING (jumped connector under dash). Removed vacume hose off of EGR and got no code, light or change in idle. Removed IAC connector and also received no change in idle nor did I get a check light.

Does anyone have a possible solution.....The dealer says worn cam lobes(#7 cyl), injectors, gasket leaks...etc. If it was a cam the miss would be consistant and the miss(lope) would not have disapeared when I changed the pcv valve hose to tbi. Injectors "look ok" but no test done...Have done the old test of pouring a "VERY" slight amout of water and then trans fluid into TBI at raised rpms to burn out carbon.....

HELP !!!!!!!!!!!!!!