Hi all

I have two problems I hope you guys and gals can help with.

68 Camaro
New ZZ4 (350)
New Holly Carb 4150 (670)
Headers

(1) Before installing the new engine, fual gauge always read way too high but it did work (move). After reading many posts on this list, I decided to check the ground wire on the fuel sending unit.
(a) While the ground wire appeardfed to be ok, I removed the screw, sanded off some junk for a clean connection and reinstalled the screw. HOWEVER, at the same time, I installed an electric fuel pump and grounded that tot he same location as the fuel sending unit.

Now the fuel gauge reads way past the full mark and just stays there permenantly.

Recommendations?????

(2) After installing the new engine and carb, we noticed that after 30 minutes or so the engine temp would get to about 235 degrees the fuel pressure would slowly drop to almost nothing.
(a) We first thought we were boiling the fuel in the lines as it comes within 3 inches of the headers on the way to the new mechanical fuel pump. So, I covered the fuel line with a heat reflector. That didn't help.
(b) We installed an electric fuel pump. That didn't help.
(c) We noticed that the dual feed line (with pressure meter) was resting on the intake manifold so I bent the feed lines and they are about 1.5 inches above the manifold and you can hold them with only a warm temp noticable. But, that still doesn't fix the slow lose of fuel pressure.

Recommendations????

Thanks all
Michael

your fuel guage problem is for sure back at the tank. The sender is not getting a ground. Something is wrong with that wire. Perhaps when you were checking it it pulled off the sender connector, or broke up under there?

On the engine thing, I'd be a lot more worried about the cooling for now. If it runs, it's getting fuel no matter what the guage says. 235 is too hot, needs fixed. Hows your timing? Retarded timing has been known to cause hotness especially at idle. Fan? Shroud? Radiator?

I'm thinking the over heating is being caused by the fuel starvation. BTW, I think I have the overheating fixed anyway. Now, I'm idling at about 200.

The timing is set for 11 degrees BTDC. The reason I set it at one more than the recommended 10 is because I'm idling at 900rpms instead of 800. (I can't seem to keep the thing running at 800 rpms.

I don't have a shroud as I installed a serpentine belt system. Radiator was low so I added coolent. I have an adjustable electric fan and the fan come on at about 200 so I think it's set properly. I suppose I could lower that to come on around 160 or 180.

You may be correct on the fuel sending unit ground. Crap, now I have to pull the tank. Too bad there is no access panel in the trunk. Since I have to pull the tank to check, I'll probably just buy a new sending unit to make sure.

Thanks
Michael

if you're running "on the fan" at 200 that may be ok. You might try dailing the fan down a lil, see if it will hold at 190? Does the fan run continuously at idle, or cycle on and off?

If the electric fan is big enough, it will do the job. It really needs to be spaced off the radiator and in a shroud tho for best cooling.

I would run even more initial, 14, 16, or even 18. The motor will like it, it will be able to idle slower, and have better response, and it will run cooler. If you do this, keep an eye on your total timing, you don't want more than 36, and may have to recurve your distributor to reduce the total.

Pulling the tank s*cks, but I'm betting that the ground wire broke off right at the connector on the sending unit. Wonder what will happen if you crawl under there and give it a *little* tug?

Your new ZZ4 probably has a 210* thermostat in it - mine did. I don't think there is anything wrong wrong with running it at 200*, as I assume GM knows what they're doing.

On the fuel pressure thing - I'd suspect a faulty gauge.

On the fuel tank gauge - I feel your pain. I just had my tank in and out 3 times f$#$^ing around with it.

Try this for diagnostics,, find the metal tube out of the guage and ground it to a good ground ( bypassing suspected broken wire) That will ground the guage. Make sure your hot side of the guage is good also and I think that goes thru the trunk? . If you have plenty of fuel in tank,,, the float should move. If not , It could be stuck, I say this as I just got thru doing the fuel tank shuffle. I filled tank and guage would not move until I made a few turns down the road. I say "could be stuck" If its not , pull the hose off and drain into other cans and say ''pull" .

I tried to ground the fuel line coming out of the tank and no luck. The gauge is still stuck on way over full.

I ordered a new sending unit and wire kit. I just saw the ad on this site for that Ground Up seller. They have an whole tank kit at a great price but the sending unit is stilol a seperate charge. Ummm, as long as I'm pulling the tank?????

I'll have to think about that one.

Michael

been there done that. One of my first tasks when I got my car was to fix the fuel Gauge. Figured as long as the tank was out I'd clean it up a lil. After a half hours putting a wire cup brush to it, it looked like swiss cheese! Guess the rust was the only thing keeping the fuel in!

New sending unit installed and all is well. Cool, no more overheating and the fuel gauge works great.

I'll change the oil this week aqnd I should be ready for Carlisle.

Hey, a quick question, Is it too early to take the new engine on a long trip? I've got 550 miles on it and things seem pretty stable.

Michael