Hi there guys...
I have an 86 Iroc-z 305 tpi with a 700r4.
I went to start my car last night after leaving the club...Turned the key and heard the fuel pump come on, but only for about 2 seconds. Then all of a sudden...dead. I couldn't get it to pump again! And that really sucked...since there were a few people standing there looking at the car at the time...but anyways!
Is there an east way to change the feul pump? Or do I really have to drop the exhaust, the cross members and the rest of the stuff.
Please tell me there is an easier way
I have an 86 Iroc-z 305 tpi with a 700r4.
I went to start my car last night after leaving the club...Turned the key and heard the fuel pump come on, but only for about 2 seconds. Then all of a sudden...dead. I couldn't get it to pump again! And that really sucked...since there were a few people standing there looking at the car at the time...but anyways!
Is there an east way to change the feul pump? Or do I really have to drop the exhaust, the cross members and the rest of the stuff.
Please tell me there is an easier way

Supreme Member
Depends on if your willing to hack-up your car.
If so, open rear hatch, pull carpet out of the way.
The flat raised portion between the rear seats and the well at the back of the car is directly above the fuel tank.
Cut a small hole right abt in the center of the raised portion so you can see where the fuel pump is at. You should be pretty close. Be careful, the fuel tank is only abt 1" below the sheetmetal.
Continue cutting hole till the fuel pump will come out thru the hole. Hole will wind-up being abt 8" or so.
You'll also have to cut 4 metal fuel lines. Splice them back together with rubber fuel hose and hose clamps. I used 2 clamps at each connection for a total of 16 hose clamps It's not a real easy job, but it is easier than dropping exhaust, rear end and fuel tank. Plus, if you ever need to get in there again, it will be easy.
Once your done, make a cover plate, slap some silicone sealant on it and screw it down.
Use short screws. Don't wanna screw into the fuel tank!
Are you sure the fuel pump is bad?
It's normal for the fuel pump to come on for a couple of seconds, then stop if eng is not started.
Mine will pump a couple of seconds the first time I turn switch on. If I don't crank eng and turn switch off then back on, fuel pump doesn't come on. If I crank eng, shut off and back on again, fuel pump come on for abt 2 secs then goes off again.
Is there something else happening that makes you think the pump is bad?
Trust me, you don't wanna replace the fuel pump if you don't have to!!
If so, open rear hatch, pull carpet out of the way.
The flat raised portion between the rear seats and the well at the back of the car is directly above the fuel tank.
Cut a small hole right abt in the center of the raised portion so you can see where the fuel pump is at. You should be pretty close. Be careful, the fuel tank is only abt 1" below the sheetmetal.
Continue cutting hole till the fuel pump will come out thru the hole. Hole will wind-up being abt 8" or so.
You'll also have to cut 4 metal fuel lines. Splice them back together with rubber fuel hose and hose clamps. I used 2 clamps at each connection for a total of 16 hose clamps It's not a real easy job, but it is easier than dropping exhaust, rear end and fuel tank. Plus, if you ever need to get in there again, it will be easy.
Once your done, make a cover plate, slap some silicone sealant on it and screw it down.
Use short screws. Don't wanna screw into the fuel tank!
Are you sure the fuel pump is bad?
It's normal for the fuel pump to come on for a couple of seconds, then stop if eng is not started.
Mine will pump a couple of seconds the first time I turn switch on. If I don't crank eng and turn switch off then back on, fuel pump doesn't come on. If I crank eng, shut off and back on again, fuel pump come on for abt 2 secs then goes off again.
Is there something else happening that makes you think the pump is bad?
Trust me, you don't wanna replace the fuel pump if you don't have to!!
Supreme Member
as said above....sounds normal to me....the pump ,primes/pressurizes then cuts off.
Supreme Member
I could imagine there's nothing worse than replacing the pump, and the car still won't run. Well, maybe... I had to replace my pump twice. 
Buy a fuel pressure gauge (for fuel injected engines). That's the $40 one as opposed to the $12 one. Then you can make sure the pump is actually dead.
There's no easy way; lower the rear axle down to the ground, pull the exhaust system straight back (after undoing the i-pipe bolts at the back of the catalytic convertor), and drop the tank.

Buy a fuel pressure gauge (for fuel injected engines). That's the $40 one as opposed to the $12 one. Then you can make sure the pump is actually dead.
There's no easy way; lower the rear axle down to the ground, pull the exhaust system straight back (after undoing the i-pipe bolts at the back of the catalytic convertor), and drop the tank.
Supreme Member
listen my tps went bad and it took the fuel pump and the computer with it and my car still wont run...does it take more spark to start the car then to run it?... theres spark at the plug theres fuel pressure at the rails i checked for injector pulse there was none so i replaced the computer it still wont start i dont know what is going on but its been a month help me out guys//
i cut through the top and it was a job....a lot easier then dropping the tank but still a half days work....i agree with it being very easy toget back into....when i did my job the pulsator came off and i had to go back in to put it back on.
i cut through the top and it was a job....a lot easier then dropping the tank but still a half days work....i agree with it being very easy toget back into....when i did my job the pulsator came off and i had to go back in to put it back on.
Supreme Member
Check the relay also. I opted for the thru the trunk method. After getting the car up on the stands and climbing under it I just couldn't bare the thought of having to do it again if I did something wrong installing the pump. Plus I pulled the old RS tank and installed the Z28 tank when I did my L98 conversion. Not fun.
I really hated to cut my trunk but I took my time, cut straight cuts etc. The scariest part is hacksawing through the fuel lines. Don't use the cut-off wheel for this! I'm in the process of fabing a cover plate that I'll seal and rivet in place. Self tappers seemed like a good idea until I though of about 15 sharp points of metal just millimeters from my gas tank.
I really hated to cut my trunk but I took my time, cut straight cuts etc. The scariest part is hacksawing through the fuel lines. Don't use the cut-off wheel for this! I'm in the process of fabing a cover plate that I'll seal and rivet in place. Self tappers seemed like a good idea until I though of about 15 sharp points of metal just millimeters from my gas tank.
Junior Member
ok this might sound stupid but it's not because I did it to mine:
just buy external electric fuel pump and mount it under the hood on the firewall make sure you get one with adustable fuel pressure and and splice into your fuel lines under the hood and reroute them for the distance you need, then you don't have to drop any of the components in the rear. But you could do this while you have the lines disconnected , take a air blower and blow thru the pressure line and blow the screen off the end of
the old pump that way it won't resrict any fuel flow(and the screen will sink to the bottom of the tank)
just buy external electric fuel pump and mount it under the hood on the firewall make sure you get one with adustable fuel pressure and and splice into your fuel lines under the hood and reroute them for the distance you need, then you don't have to drop any of the components in the rear. But you could do this while you have the lines disconnected , take a air blower and blow thru the pressure line and blow the screen off the end of
the old pump that way it won't resrict any fuel flow(and the screen will sink to the bottom of the tank)
Supreme Member
Mine wouldn't syphon through the in tank pump ...as seems to be the case with about 50%..
Supreme Member
come on guys i need some help here
parts that have been replaced or checked...
theres spark at the plugs
the tps has been replaced
the iac cleaned and tested
new plugs
new fuel pump
new computer
new fuel pressure regulator (putting it on wednesday morning)
could the map sensor be bad??
when i spray fuel into the tb it comes right to life then dies when the gas is burned...i know the oil pressure fuel switch is good because i hear the pump pump when i crank the car
what could it be??...my car hasnt started in a month and im pullin my goddamn hair out
parts that have been replaced or checked...
theres spark at the plugs
the tps has been replaced
the iac cleaned and tested
new plugs
new fuel pump
new computer
new fuel pressure regulator (putting it on wednesday morning)
could the map sensor be bad??
when i spray fuel into the tb it comes right to life then dies when the gas is burned...i know the oil pressure fuel switch is good because i hear the pump pump when i crank the car
what could it be??...my car hasnt started in a month and im pullin my goddamn hair out
Supreme Member
Quote:
Originally posted by f-crazy
come on guys i need some help here
parts that have been replaced or checked...
theres spark at the plugs
the tps has been replaced
the iac cleaned and tested
new plugs
new fuel pump
new computer
new fuel pressure regulator (putting it on wednesday morning)
Do this and get back here with results, and check the fuel pressure in the rails. If you don't have a guage, before you pull the old regulator, turn the key on to charge the fuel system, turn the key off, take a rag and a small screwdriver and cover the schrader valve on the fuel rail and push the stem down with the screwdriver. Do you get a good hard stream of fuel out of it? Yes? Change the regulator. No? Find the blockage in the line between the gas tank and the engine.Originally posted by f-crazy
come on guys i need some help here
parts that have been replaced or checked...
theres spark at the plugs
the tps has been replaced
the iac cleaned and tested
new plugs
new fuel pump
new computer
new fuel pressure regulator (putting it on wednesday morning)
Quote:
could the map sensor be bad??
That wouldn't explain why it does start when you spray gas or starting fluid down the throttle. So, even if it was bad, the car should start, as long as it is getting fuel.could the map sensor be bad??
~M~
Supreme Member
I agree; f-crazy, buy/rent/borrow a fuel pressure gauge.
Senior Member
lost my fuel pump too, but have a carbed 305, 3 hoses, 2 bolts and mine fell right off, little older tech but so much easier 

Supreme Member
Still no injector pulse? How's the Fuse? Did you swap the PROM/Memcal into the new ECM?
Supreme Member
there is fuel at the rails both when i charge the system and when im cranking...i bought a regulator today and when i got the plenum off i discoverd that 2 of the screws were stripped like the previous owner was gonna change it and didnt do it becasue he stripped the screws nice guy right could of told me....i got the other 4 off but how the hell do i get the other 2 off?...could/should i cut the heads off them and seal by othere means with the other 4 i dont wanna tap them out but if i have to i will...i tried to get the whole regulator assembly off but it wouldnt come off...like i said its been about 5 weeks and im ready to get it outta my hair shortly unless i can get this taken care of....thank alot guys
"crazy"
"crazy"
Supreme Member
Quote:
Originally posted by f-crazy
when i did my job the pulsator came off and i had to go back in to put it back on.
Aw, man, I shoulda mentioned that... the pulsators can leak. They're just o-ring seals. On my first pump, I reused the original pulsator, then found out about the o-rings. When that pump died Originally posted by f-crazy
when i did my job the pulsator came off and i had to go back in to put it back on.
I didn't bother with a pulsator, I used the bit of high-pressure hose that came with the pump.Sounds like your pump wasn't dead to begin with, eh?
Supreme Member
Quote:
Originally posted by f-crazy
....i got the other 4 off but how the hell do i get the other 2 off
Get a hold of a Dremel tool with a cutoff wheel and cut a small slot in the head of the screws for a common screwdriver.Originally posted by f-crazy
....i got the other 4 off but how the hell do i get the other 2 off
~M~
Member
I know this is going to sound really strange..
last year, my car started sputtering, and died.. just like it ran out of gas. It started right back up and drove for about a mile then died again (felt just like running out of gas). No restarts, but it came close a couple of times.
I thought it must be the fuel pump!! The pump ran, but like someone above said the pulsators leak (and this has happened to me before).
Anyway, it turned out to be my coil, which I never thought about checking because people say that they rarely go bad.
last year, my car started sputtering, and died.. just like it ran out of gas. It started right back up and drove for about a mile then died again (felt just like running out of gas). No restarts, but it came close a couple of times.
I thought it must be the fuel pump!! The pump ran, but like someone above said the pulsators leak (and this has happened to me before).
Anyway, it turned out to be my coil, which I never thought about checking because people say that they rarely go bad.
Supreme Member
i broke my last cutoff wheel because i tried that last night...adn i dont have $$$ to get some more...im gonna try to bend up the collar a little bit to break the screws i know i can bend the collar back to form but will it seal with the 4 screws and something else on the 2 others...maybe some kind of c-clamp??...i dunno what to do guys....im up ****s creek without a paddle...i dont care if it looks crappy as long as it works
let me know what u guys think...
and the pump was bad
the tps was bad and it made the fuel pump work 3 times harder then it had to and made the computer work harder then it had to everything ive replaced was bad so i havent wasted money...thanks for the help guys
let me know what u guys think...
and the pump was bad
the tps was bad and it made the fuel pump work 3 times harder then it had to and made the computer work harder then it had to everything ive replaced was bad so i havent wasted money...thanks for the help guys
Supreme Member
ohhh as far as the coil being bad.....the car runs when i spray fuel into it..its definetly fuel related and the only other thing in the fuel system that hasnt been replaced is the regulator
Supreme Member
today i got the regualtor off and put the new one on cranked it and it still will not start....i opened the valve on the fuel rail while my buddy cranked it and it started but idled at about 200 rpm's soon as i closed the valve it died....i sprayed fuel into the tb and it started then died wtf is going on i dont knwo anybody want to buy a gta....
Supreme Member
This is getting stranger as you go. You say you let off fuel pressure at the rail and the car started? Do you know what the fuel pressure is? Sounds like it is too high and keeping the injectors closed.
Try this, since the car won't start anyway, take a connector off of one of the injectors and hook a test light (the 12 volt kind that looks like an awl) to the harness, have your friend crank the car and see if the light flashes on and off, it should be fairly bright too when it is on. I suspect it may be too high of fuel pressure or possibly the injectors aren't getting a full 12 volts and therefore can't open with fuel pressure on them.
Keep the results coming, I love a good challenge.
~M~
Try this, since the car won't start anyway, take a connector off of one of the injectors and hook a test light (the 12 volt kind that looks like an awl) to the harness, have your friend crank the car and see if the light flashes on and off, it should be fairly bright too when it is on. I suspect it may be too high of fuel pressure or possibly the injectors aren't getting a full 12 volts and therefore can't open with fuel pressure on them.
Keep the results coming, I love a good challenge.
~M~