First off I hope I don't chase anyone away by starting out saying I have a 91 Caprice 9C1 (ex police car) that started out life with a L05 350 which is why I'm posting here. It's so similar to what a lot of you guys are running. The new motor is all in the car and running but not very well. Here's a parts list:

- Replacement Caprice TBI 350 crate motor (minus the standard heads and cam...which are for sale if anyone is interested)
- Vortec heads
- Vortec TBI intake (from GMPP)
- LT4 (not hot) production cam
- Vortec exhaust manifolds with external EGR
- reman. HEI distributor, new cap, rotor, coil, wires, plugs
- stock TBI with 65#( I think...) injectors but with the vacuum adjustable fuel pressure regulator using the spring that came in it....didn't swap in the one from the original fpr.
- complete stock dual exhaust setup from an LT1 Caprice (true duals, 2 cats, 2 mufflers, 2 resonators, no crossover in case you were wondering)
- I have the most current version ECM in the car but that is stock as well.

I didn't do the work, I had a mechanic do the install/assembly.
It starts up ok, idles ok, temps don't get too hot and oil pressure is steady and good.

Here are the issues:
#1 - The engine is making a noise after it gets nice and warmed up. It starts out real quiet and gradually gets louder and louder till the engine is completely warmed up. I doubt anyone will know what this is just from this description but what the heck its worth a try. It appears to be vaccuum/pressure related in some way becuase as it first starts to come in accelerating or even braking (I assume drawing vaccuum for the booster) will make it stop, but once its fully warmed up only decent 1/2-full throttle acceleration will make it completely quiet down. The sound is fairly high pitched and pulses. Tone and volume does vary a bit with RPM. I have access to a digital camera that can take mpeg movies and will be recording the sound and posting it within a few days hopefully.

ADDED - Ok...I have second opinion on this. Since I was outside messing around with it. Wouldn't call it whistling now (sounds a lot diff outside the car than in with the windows up). The best description is a bearing noise that varies with RPM. But the thing that gets me is that (once it's all warmed up and does it all the time...) if I turn the car off the noise kinda peters out in a matter of like 2-3 seconds. It doesn't stop immediately with the engine and kind of wheezes to a stop. At that point it sounds like air. When I start the engine after that, it takes about 4-6 seconds for the noise to start and it quickly (<= 1 sec) raises in volume to full at that point.

#2 - As mentioned at the start, the power really isn't there like I was expecting and it doesn't really run that good past 1/2 throttle. It has even backfired a couple times.

#3 (related to #2 I'm sure) - If I use 3/4-full throttle it will light up the SES light and set a code 53 (I think that's the right #) which is for ESC, electronic spark control (too much knock/ping), on this car and the car loses all power (It did this while doing 75 on the GSP in NJ and I just gradually slowed to like 40...it wasn't pretty. Removed he ECM fuse for a couple mins to reset the code and drive the car home.) The mechanic replaced the knock sensor and the knock module as well as the the newer ECM which specifically addressed a knock issue. Mechanic has told me he set the timing to 0 degrees at TDC with the ESC connector unplugged as per the Factory Service Manual.

#4 - Mechanic mentioned to me about the spark plug gap possibly being something like .10 too large. How bad, if at all, is that for engine and how much would/could that affect performance or any of the other issues.

I am thinking the car probably needs a custom PROM burned and I am planning on using Ed Wright ($350 ish) unless I hear otherwise (hint, hint). I know this would help out the performance and general driveability and don't think it would have any effect on the knock/ping issue, but wanted any opinions on that. He has spent 2 and half months up to this point doing the work and this was my daily driver. Any reccommendations/suggestions please feel free to post and/or contact me directly (email should be public as well as AOL IM name).

Oh yeah...also, what would be a good handheld scanner unit/laptop+software to get that would allow me to see what's going on in the ECM? I've heard about TurboLink meant for Grand Nationals but works for my car.

 

Welcome to thridgen.org.

The noise may be an accessory (power steering pump, alt...). Take the belt off and fire it up and see if the sound is still there.

You may want to venture over to the TBI board, someone there probably has a similar setup that can help you out. I've seen the stock Caprice crate engines run fine in the RS F-bodies (originallly with 305's) with larger injectors and the 305 PROM.

I'd doulbe check the plug wire routing and verfiy that they're on going to the correct cylinders to start with.

Your stock programming should be able to run the engine, maybe not to full potential yet, but shouldn't (IMO) cause the problems you're having...I'd try to fix them first before trying to adjust EPROM settings.

 

There is a ring inside the alternator that is supposed to be attached to the armature. It's loose. That's what's making the noise: it's spinning around the outside of the armature; it's not moving as fast as the armature so it makes the noise when the alt accelerates, it will shut up when the alt slows down gradually, but it cintinues to spin around for a second or 2 when you shut the engine off. It is of no particular consequence; but if it bothers you, you can epoxy it back to the armature, or get another alternator.

The driveability problems sound to me like extreme lean-out. Check your fuel pressure while it's malfunctioning, I'm fairly sire you'll find it's low. You might want to try the obvious and put a new fuel filter on it. Your buildup doesn't look like its fuel requirements should be that different from the original, so I'd look for broken stuff before playing with chip programming.

Spark plug gap is irrelevant.

 

It's not the accessories. The engine was run with the belt off and the noise is still there. It's also not the transmission as the torque converter was unbolted and it still makes the noise. It takes about 15-20 mins from a cold start to start making the noise.

Mike, you mentioned trying the TBI board. Should I just cut+paste the whole post over there?

RB83L69, someone else was saying leanness is causing the code 43 as well. I'm using the vacuum adjustable fuel pressure regulator on the TBI that is meant for a 502 and hence the spring in it is meant to deliver about 18-20psi. I left that spring in there so it would seem to me that if anything it would be rich, but I may be wrong. I don't have a guage on the line yet, but would really really really like to install on as I'm sure it would be a big help for the driveability issues.