Hey guys! It's been a while! I'll catch everyone up to what has been done on my 1991 Z28 Camaro.

Let's see here, I dropped a rebuilt 1988 IROCZ engine in, with upgraded cam, roller rockers, hydraulic lifters, everything machined, cleaned, bord .3 over. It is "technically" a 310 V8. It has roughly 5.2k miles. I kept my 1991 wiring harness due to the computer. It works perfectly. I do have a tuning system that I have yet to use, it came with the engine. An Ostrich 2.0 Tune-System. Not even sure if it works with the 1991 Computer. The engine runs smoothly, no misfires, no hickups, no bog, it's never stalled, loves high speeds 65-95. 4 grand in minor upgrades, 3 grand on machining.

I got the original fuel tank cleaned, pressure washed, sandblasted and coated in a rust resistant spray. I installed a new fuel sending unit along with a Holley high performance fuel pump, roughly pushing 255LPH. The old ACDelco pump went bad due to rust in the tank. When they cleaned it out they said they could fill a whole cup or 2 full of rust particles.

Now, on to my current problems. The two that concern me the most after all this work is the slight over heating (sometimes major) and the fuel pressure being dropped after it's been running a while.

This is what happens, after about 5 minutes or less of running, the gauge stops at about 160 to 180 degrees, if I stop at a red light, it goes down a few degrees, then when I accelerate it goes up a few. Until it reaches 220. Even 220 isn't healthy for the engine! When it gets to that point it fluctuates from 220 to 240. When i'm at a stop, it would read 220, when I accelerate, it goes up to 230 even 250 in a matter on about 10 seconds! I have a piece of crap temperature sensor from Advance Auto in there right now, so maybe it's reading incorrectly? However, the radiator sat for 4 years while still connected to the old engine, it was never cleaned out to my knowledge. The thermostat was said to have been replaced before I purchased the new engine. I have receipts on everything done to the engine, except the thermostat. I noticed my rubber coolant hose that connects from the thermostat metal jacket to the right side of the radiator looks bloated where the thermostat jacket is. Not sure if this means anything but i might as well throw it out there. Both fans work fairly well to what I've heard. I'm not really sure what could be the cause of my over heating. I'm not sure if the radiator is clogged, thermostat is broken, sensor is reading incorrectly, or what ever else it could be. Fans even.

Now, for the pressure issue. After all these new parts for the fuel tank and the cleaning, I still have pressure issues. After about 25 to 30 minutes of driving, 5 minutes of highway driving, the fuel pump starts to whine very faintly, and acceleration drops a bit. Now, I've had this problem before all the fuel tank stuff was done. It would whine so loud you could hear it a block away. As of right now it's very faint but I think that's because it can put out enough fuel for the engine. I would assume I have a kink in my fuel line, correct? The whining is from an over worked fuel pump, correct? Plus after all these repairs I still have this issue, many many things were trialed out from the repairs. A kink is really the only other explanation? I do notice that the camaro is usually a dog with acceleration. Very slow, sometimes doesn't accelerate tightly. It basically lacks power in the pedal.

I would like to be able to go to Texas in the next couple months. I'm down here in Florida. With the car in this condition I will not be able to make it. I want to get it so if I wanted to go to North Carolina, Vermont, Texas, anywhere, I won't have to worry about it. The over heating and fuel pressure is whats stopping me. Everything else is just cosmetic.

Thanks in advance guys! I could use any and all help with this!

EDIT: By the way, fuel pressure was much MUCH worse before the fuel tank repairs. The car starts up in one crank now, almost instantly. Except after the 35 minutes of driving of course. Then it takes 2 or 3 turns to get it on.

 

From the sound of it, your engine is running hot more while the car is in motion? Check to make sure the air dam (that spoiler looking thingy) is still hanging down in front of the car. It's set back from the bumper a bit, and helps to direct air up through the radiator.
You're mentioning fuel pressure issues, but didn't say whether you checked it with a gauge. Are you just assuming it's a fuel pressure problem? Could be a pinched supply line, or your return line could be restricted making the pump work harder. Did anybody modify or disconnect/cap off any of those "useless" extra fuel lines?

 

The air dam is there and it's tightly secured still. The pressure was checked and it starts out at 10psi and slowly works it's way up to about 36. 40 psi is required for my car. I just realized, if I had rust in the tank, couldn't there be rust buildup in the fuel lines as well? They are metal lines.

 

Nowhere in your novelette did I see you mention replacing the fuel filter. I hope you did, otherwise it could very well be clogged pretty badly considering the amount of crud you described.

 

Just a shot in the dark, is there some sort of tank vent line that that is clogged making the fuel pump whine as it cavitates trying to pump? Happens on hydraulics quite often, not sure if this is relevant for a fuel tank.

 

I can't speak to the fuel scenario, but can touch on the temperature deal. I can't stress enough how important it is to leave nothing to chance. It sounds like you spent a pretty penny on a "fairly" stockish motor. There is nothing wrong with this at all, but with all that coin spent, do not skimp the free (or cheap) and easy stuff. If you used all of the wiring harness, then why does your factory gauge not work? I realize the factory gauge is not the most accurate thing in the world, but it would be nice to have all things functional. This should just require the correct sending unit that threads into the drivers side head and is connected by a spade terminal single wire that come from the firewall from around the brake booster area.

Next, flush the radiator and clean the condensor out to ensure years worth of debris isn't impeding airflow to your radiator. Next, assure that both your hoses are good. I know you mentioned the top one maybe being swollen, without seeing it, it sounds like it could be time to swap that out. Pay special attention to the bottom hose, there should be a spring inside of the hose to prevent the hose from collapsing. Keep in mind the bottom hose is the "cold" water that is being sucked from the water pump into your engine. If that is all fine and dandy, check to make sure you have a thermostat in place and it is of the correct temperature range. If that is good and your fans are coming on at the desired temp...in this case it actually is around 220 degrees as these generation of cars were designed to run slightly higher than the 190 degree standard of yesteryear. Higher temps help reduce emissions.....

You mentioned you have a "cheap" temp gauge. How is that hooked up?

 

there should be a vent for the tank to allow air in to replace the fuel that has been drawn down. i havent looked around for a correct replacement since i removed my evap canister, but just an open evap line will not work as fuel will drip from it

 

Sounds like you're looking for a way to vent your system? A vented gas cap will let air in to displace the gas. Vented caps act like a check valve, and breathe in, not out.

 

To sum just about everything up:

I hay have misspoken about the temp gauge. I meant to say a temperature sensor from advance auto. My guage is original still in the cluster. It was a cheap 20 or 30 dollar sensor.

I just notices that it heats up very very quickly. Right now it's 73 degrees here in Florida. When I woke up this morning it was around 68, 69. I drove 5 minutes and it was already at 220. To me that seems impossible! How?! Until I turned on my second fan. It only kicks in when the A/C is on because it was wired differently by my old mechanic.

I'll replace the sensor with a factory ACDelco part. Maybe that'll fix this supposed "overheating" the engine takes a lot longer than that to heat up. It was steady while I was driving, then I hit a stop light for a minute, and drove another 2 minutes to work. It shot up from 140 to 220 in a matter of seconds, until the second fan is on. Then it stops climbing and goes back down to 180 for a bit.

And yes, the fuel filter has been replaced.

 

Update! I dropped my car off at the mechanics today and they found a vapor leak. I am not sure if this would be causing my problems? They can't seem to find anything else wrong with the fuel system. They are looking for a new canister but apparently it's a part that has been discontinued. Any ideas if this could be the culprit of my problems?