My car is a 92 camaro with a carbed 350. It was running fine then it died out on me driving home, I took out the old icm and it tested bad, bought a new one and ran fine for a few more days until I changed sparkplugs then it ran for(as long as fuel was in the bowl) about 5-10 seconds. The pump primes and I have no clue what's going on

 

And the car has spark

 

You say it primes, but is the pump running when you crank the engine?

Are the carb bowls filling with fuel when the fuel pump primes?

have you checked fuel pressure?

I would start by testing the fuel pump..

 

Yeah I'm gonna test it today, it fills up the bowl then starts and runs till the bowl empties. I was told a short in the wiring could cause that

 

Ohk I did a test and I'm pretty sure the fuel pump is gone, my car only runs constantly if I reset the fuel pump every time it starts to die out

 

Maybe the relay and hopefully not the pump? Just a thought. I'm not sure how you're resetting it, but this might save you some cash and time...

 

I already put 3 different relays on it and no luck, I'm resetting it by removing and replacing the fuse right when it starts to die

 

Welp, that's no good. Does it run only the length of time it normally primes when the key is turned on, i.e. 2 seconds? Or is it running and then slowing to a stop? If it's the second, then I'd go with the pump. The first might be a wiring issue controlling the pump.

 

Ittl run for like 30 seconds then slow and die out, that's when I reset it. I'm leaning towards the pump now and a new rear end as well since that's gotta come off lol

 

You do not have to remove the rear end to drop the fuel tank.

but you do have to remove the muffler, pan-hard bar, fuel filler door, fuel cap, and trim ring. removing the over axle exhaust pipe also will free up some room.

it will be much easier if the tank is "empty" versus full

just make sure you jack and support car from the sub-frame points, this will raise the body and lower the axle giving you plenty of room.

You could disconnect the shocks and jack the car high enough to drop the rear end... but I have done it with the axle in place... why make more work for yourself?

 

I have a fourth gen rear end sitting there so I figured while I'm down there I should install it, plus won't I have more room if the rear is removed?

 

A 4th gen rear is not stronger than a 3rd gen.. it's still a weak 7.5" 10 bolt..

maybe you will get lower gearing and possible posi-traction but when you start making some real power this will be the first part to fail. In my case I broke the transmission first. Then after I beefed up the 700R4. I took 4 teeth off the stock ring gear at Cordoba back in 2001...thankfully I trailered the car to this event. I had the 10 bolt ring & pinion replace and in 2005 I replaced it with a 9" Ford.

I don't know what your long term goals are but these OEM parts will not stand up to real abuse at a track.

So rather than doing it twice or more my advise is replace the fuel pump and save up a real rear end

 

My car is an rs so it has 273 gearing and open diff. The 4th has 342 and posi, plus it was free, isn't that better? When my car was stock I hit a 15.0 on the 1/4, I'll be happy with low 14s cause it's a dd

 

If it's a DD, I would leave that 2.73 in there for lower cruising RPMs. But, if you really want the higher ratio, you can replace it. It probably isn't as much of an upgrade as you might want, but if the ratio is all you're looking for, I'd say go for it. You can drop the tank without dropping the rear axle, but it's probably easier without it on the car.

 

I want posi! Lol and the gearing is crap, I only hit 2 gears at the track

 

I'd say go for it then. It might make it easier to replace that pump anyway, so since you'll be down there anyway, get it done too I guess. Does it completely match up or will you have to do any modifications?

 

Complete match

 

2.73 * .7 OD = 1.911 final drive ratio


3.42 * .7 OD = 2.39 final drive ratio


3.73 * .7 OD = 2.61


A 3.42 will give you better acceleration versus the 2.73 and cruising RPM will still be very good because of Over drive.


BUT a 3.73 (minimum) will be much better if you are going for 1/4 mile performance and still give you good cruising RPM for a DD.


Since your 4th gen rear already has 3 series ring & pinion you could easily replace that for 3.73 for a couple hundred bucks.


Keep in mind the 1/4 mile is purely an acceleration test... ideally you want the lowest gearing possible so you are crossing the finish line with the motor revving at peak power.

with a daily driver it is balancing act because that 4.10 gear may be great on the track but you may not like on the highway even with OD..

3.73 or even a 3.90 is a good compromise for a DD...

Ideally you should match the gearing to the power band of the engine, for a "stock" to "modified" SBC a 3.73 is usually the gear of choice for a street / strip car. since peak power will be between 5000-6000 RPM anyway.


Good Luck !

 

Thanks! That was helpful, the 342 is fine for now, and your right about the 3 series carrier. The important thing as well is that the 4th gen rear has posi which my stock one does not

 

Ohk so I put a new fuel pump and still no luck! And now my gas gauge is messed up

 

Because of some misinformation I was led to believe that my relay was the one on the pass side firewall. It turns out to be the on on the drivers side, I'm going to replace it And my car is going to work lol

 

I dindt know which were the good gears for 3rd gens til i read this article lol. Which one would yall recommend for my 90 RS V8 TBI

 

Ohk news, I jumped the fuel pump relay and the car starts and runs fine, put the brand new relay back in and ittl die, shoul I buy a new relay?

 

I got a new relay and ittl die within 30 sec of start, ittl start and run fine if I bypass the relay.

 

Are you using a brand new relay or a used one?

Obviously if you jump the relay and the pump runs, the problem is isolated to the relay.

The relay itself could be bad, or perhaps the terminals (s) on the relay are corroded, or you have a poor ground to the relay.

you can clean the terminals with contact cleaner and a fine small file (nail file) and use di-electric grease.

The most important thing(s) with electronics is proper grounding.

 

I used two different brands of brand new relays. Why will it run with a jumped wire but not a good relay

 

You'll have to do some investigating here to find the issue. What was your car originally set up as? TPI? TBI? I have attached a fuel pump circuit for you to take a gander at. It should be the same or very similar to what you're working with, unless you have vastly change the original fuel system. It could be your oil pressure switch going bad, though I have never actually seen what happens when the switch fails. You may want to check the ground for the pump. Is it grounded properly? Is it grounded near the fuel pump or does it run back forward through the car? Maybe something happened during the re-install of the tank? I've never replaced my fuel pump as luckily the PO changed that right before I bought it . Anyway, hope this diagram helps.

 

Thank I'll look into my wiring, my car is originally a tbi, it's been switched over to carb, still electric fuel pump though

 

It wasn't my fuel pump, it ended up being the wiring around the relay! Check ur wiring everybody! Haha