I have a 1999 Chevy Tahoe Z71. I recently replaced the 5.7 with a GM Performance HT383E engine. The engine is touted to have 322 HP and over 430 lb ft of torque when mated with OEM injection, exhaust intake, parts. While the engine is stronger, it is not representative of the claimed increases. I had already fitted the 5.7 with edlbrock headers, a flowmaster cat back system, an AEM Brutforce Intake, and a SUPERCHIPS power programmer. These additions made significant and noticeable gains on the OEM engine with 160K miles. When I put the new engine in, I was able to mate all those bolt-ons in the swap. However, it doesn't produce the neck snap one would expect with almost 100 more HP and 100 more lb ft of torque from factory specs. It just seems to be starving. It sounds really mean and has a noticeable lope with the stroker configuration, and it is a little more peppy, but opting for a $5k upgrade instead of a $2k upgrade is simply not being realized. I'm wondering if I need a high-output igntion system to aid in the burning of the fuel. I've noticed that the residue leaving the tailpipe is leaving a good bit of soot, indicating unburned gas escaping.
Now. Onto other new issues. The truck idles with a slight surge, sometimes elevating to a rise in RPMs, countered by a reduction that almost mimicks dieseling. In addition, my wipers only work randomly and start and stop on their own. My AC blower is also not working all the time. Sometimes all the settings work and sometimes only some of the settings work, and sometimes none at all. Also. My previous engine lost oil pressure and the gauge moved a bit back and forth for a few minutes. When the truck was returned to me after the swap, the oil pressure gauge was stuck on a wide open (far beyond the highest pressure reading) position. It does not fluctuate or bounce at all regardless of engine speed.
So. That's about it. I love my truck. I was eagerly anticipating the performance beast I put under the hood. It seems I didn't get much of a bang for my buck and I now have "gremlins or ghosts in the electrical system". Any ideas?
have the same problem?
Tuesday, September 23rd, 2008 AT 2:38 PM