I have a 91 z28 with a 305 tpi i just bought and well i been trying to make it start and well it only starts when i put carb cleaner and then once it finishes it turns off. Could that be the fuel pump or fuel filter? OH and the car has been sitting for 4 years too i that helps to know.
Any advice would be great and if you need more info i can say too.
Thanks in advance

 

any backfires, how is the distributor did u replaced it or using the one it came with?

 

Im using the distributor that it came with, and yes it does have backfires

 

that might be your problem, try using the distributor from your rs, also make sure the spark plugs and your firing order is correct, and make sure your dist is set at top dead center to begin with.

 

Oh alright ima do that tommorow and ill update on that

 

If it's been sitting for 4 years with no fuel stabilizer added to it, the fuel system at best is gummed up. Gas turns to varnish without a stabilizer, and eventually to tree sap.

Is the fuel pump priming at all? Have someone turn key to on while you listen at tank (put ear against gas tank).

1) Replace the fuel filter
2) add Seafoam to tank as per directions
3) see if car will start then

If it does, then run all that gas out, refill tank 1/2 way and add seafoam again, and run all that out. Car should start running better and better as the old gas is ran out and the seafoam cleans out the varnish.

 

The fact that the engine starts with carb cleaner makes it fairly obvious that it's not a problem with the distributor. Follow camaronewbie's advice on the fuel system.

 

Oh alright ima go get myself one of those bottles and try that, also i forgot to mention i added 4 gallons of gas too try if it started would that fixed it up a bit or just made my problem worser.

 

Adding fuel wont hurt anything. Unless you end up needing to drop the tank and replace the fuel pump. Did you check the pump as camaronewbie suggested? That's the first thing you need to do. Then check fuel pressure to determine that the pump and regulator are producing sufficient pressure. Then do the seafoam treatment.

 

Well i really didnt hear anything by turning the key, and how would i check the fuel pressure do i need some certain type of tool for that?

 

You can "rent" for free a fuel pressure guage from Advance/Autozone - driver side fuel rail there is a schraeder valve (looks like a tire stem) - pressure guage will attach there.

When you go to replace that fuel filter, hold a rag over that schraeder valve and push it in with a phillips screwdriver to release the pressure, then you won't get a face full of fuel when you replace the filter.

If you pressed your ear aghainst the gas tank while someone turned the key on, and you didn't hear the fuel pump make a whining noise for 2 seconds, then you have a fuel pump issue - check the fuel pump relay 1st.

 

Excuse me camaronewbie, the shrader valve is on the pass side fuel rail.

 

Hmmm - always thought it was driver side. Oh well, at least I remembered there was one, all my 3rd gens were TBI or carb - had to cut in a guage on the rubber fuel line - always envied the ease of the schraeder valve.

 

Oh alright ima have to do that then. Also were is the fuel pump relay located?, sorry for all the questions i really dont know any of this thats why.

 

The fuel pump relay is on the firewall between the brake booster and left fender. There are a couple of relays there. You really need a wiring diagram at this point to know where to test. You want to look for power coming from the relay to the pump for 2 seconds when the key is turned on. And when cranking the engine. It should be a tan/white wire but Im not sure of wire colors on the 91. Search for wiring diagrams.

 

Yea im having the same problem I got a 89 camaro irocz from my brother its been sitting up for a few years I replace the fuel pumo and fuel sending unit and the fuel filter the gas tank did ha a bunch of stuff in it that did look lik tree sap I cleaned all that out and dropped the fuel sending unit and fuel pump in it but it wont crank and I dont hear the pump cumin on wat could that be

 

yungcris09 its relay or bad wiring as for sick rs check the injectors they might be gummed up from sitting,you can get a set from jy for cheap

 

were is the relay located on the car and wat does it look lik

 

i belive its the second relay on the fire wall,not 100% positive,my car is completely carB,alsdo u can check that the fiel pump is getting power by folding the rear seats down and putting a test light on the tan wire on the wiring harness in under carpet,then turn key if u get power its not the relay

 

Ok then imma try that tomorrow and see wat happens thank for your help

 

im new here but i had the exact sane problem my brother bought the camaro from and old man 7 years ago he got into some sh*t and did 6 years in federaql prison till i bought it from him. just like you when i would prime it with gas or carb cleaner it would turn or or back fire. well what my mechanic ended up doing is replacing the fuel pump and tbi its was all gunked up from seating so long.

 

I am new here too, seems that camaros dont do well sitting for too long. I have that same problem on my 90 RS 305. it will run with carb fluid or regular gas but as soon as it ends, it stalls. P.S it has been sitting at this car lot for a year.

 

Yea true cause I got my car from my brother and its been sittin up for about 5 or 6 years and it want to crank just aint gettin gas to it and I put all new fuelpump fuel sending unit and fuel filter on it I just gotta check those fuses and relays

 

i think mine has a fuel blockage issue because if i move the trottle back and forth continously i will keep running but causes explosions. starts quick but if i dont move the trottle it dies instantly.

 

Do u kbow if your gettin then right amout of fuel pressure from then fuel pump I thibk on tbi it should be 15 psi

 

Oh never tought about that, since i just purchased this vehicle last week. havent really done anything to it, but from what i have read. does TBI have a stem along the fuel line to connect a pressure gauge?

 

The 3gen TBIs dont have the schrader valve for testing fuel pressure. You have to disconnect the largerer of the two fittings from the back of the TB and, using adapters, T in a fuel pressure gauge. A master fuel pressure test kit will have all these adapters. It's a pain but that's how GM did it.

 

Well today i found out the pump only sometimes it makes noise but not everytime, so later on today my dads friend is a mechanic and is gonna check it out hopefully i get it runnin

 

i did the old fashioned pressure test where i loosen the main line in the tb, juiced the fuel pump, whick by the way makes noise, but only fuel trickles out of the line... so i believe its very little pressure. dropping the tank later on today. will post findings.

 

Did you check the fuel filter before pulling the tank?

 

Ok well my dads friend did not go over so i wanna know how to test the relay or should i just buy a new one.

 

yes doctor, i did,new filter then did the test. unfortunately due to weather i was not able to drop tank last night. I'm leaning towards the fuel pump at this time. i did a spray bottle full of gas, sprayed the tb and jumped the starter stays running as i spray the bottle, but nothing comes out the injectors. if i let the car sit for 10 seconds, then crank it, the injectors work but as soon as it turns over they quit.

 

It probably is the pump. I've had one two very strange issues where the injector signal would drop out once you released the key from crank to run. Found bad ignition switch. just keep that in the back of your mind. A noid light found the loss of injector pulse. A test light found the issue at switch. Can seem very weird at first.

 

You try shooting some compresses air in your fuel line towards your tank to see if your line is clogged. Im not sure if the in tank pumps have pickup screens but that may be your problem.

 

it very well could be the strainer thats clogged. good advice, nitro. as for doc, you havve that thread stuck in my head about the injector pulse. will post new findings as soon as weather permits...

 

Be careful with this on in tank pumps. This can damage the intank components. I would not see a problem doing this with the pump out and disconnected from the sending unit.

 

Which lines go where when putting the fuel pump back in? There's 3 or four different lines on the sending unit. Where does each one go? Can some one provide a pic would appreciate it.

 

Assuming there haven't been any modifications to the OE fuel lines, it's pretty straight forward. There are two rubber lines with threaded fitttings on the end. These are the pressure and return lines. they are different sizes and will only go on their respective fittings on the steel lines. The other two lines frrom the tank are one to the canister and one to the fuel tank pressure control valve. They are also different sizes so placing them should be fairly simple.

 

Is there a way that I can just wire the fuel pump up direct to the battery and put a cut off switch to mak the fuel pump work with out burning up anything

 

The OE fuel pump circuit was engineered to work well and be quite reliable. If yours doesn't work, fix it. I dont like the idea of toggle switches on fan circuits nor do I like toggle switches for fuel pumps. Racers run them that way because it's simple and saves the weight of a relay and wire, but racers don't drive their race cars on the street everyday.

 

Well we tested the relay today and its working so could that mean the pump is going out? also the fuel filter has been replaced already

 

 

If the relay is proven good, jumping it won't help. You should check for wiring faults between the relay and fuel pump before you go through the trouble of dropping the tank though. Going by what's posted above, check for voltage in the tan wire in the harness inside the car above the fuel tank. There should be 12v there for a few seconds every time you turn the key to on.

Also the connectors at the fuel pump have been known to go bad, so if you do end up replacing the fuel pump, be sure to plug in the electrical connections and make sure it works before you even put the pump in the tank.

 

 

NINA's right on with the pump test. To test the relay and the pump, jump the large orange wire to the green/white wire. The relay should click and the pump should run.

 

Thanks for the correction on wire colors (I was just going by what someone else posted) and fuel pump lockout delay.

However, jumping the relay in the engine compartment will do absolutely no good of there is an open wire between the relay and the pump. I stand by my advice to check for power as close as possible to the fuel pump.

Jumping the relay will either mean:

Fuel pump is good. (if it runs after you jump the relay)
Wiring is bad (if the pump doesn't run)
OR the pump is bad (also if the pump doesn't run)

 

Duplicate post

 

All true. that's why you're correct in saying that before you drop the tank, check for power as close as possible to the pump.(C307 is the connector right above and forward of the tank) Jumping the relay as explained above is a good way to assure that the relay is powered for the test of C307. If I didn't already say it, be sure to verify ground to the pump as well.

 

OK so to the test the relay how you guys say do i just have to have to put a wire to the orange and grey wire correct or did i understand wrong