im trying to replace the fuel pump... i've got a book and everything for it except maybe the right tools.. the book is saying i have to disconect the exaust system so im trying to remove it at the muffler... do i need to heat the fitting first or what? please give me some idea on what i need to do... my mom got the car towed to my house when i wanted it to the shop to save me whats going to be alot of hard times... maybe a quicker way such as going through the back seat? help me please

 

Anything having to do with the exhaust is an absolute pain.

To drop the tank you'll definitely need to drop it. Heat helps unstick exhaust, so does a big sledge if you have a right angle.. Is it possible that the last person who replaced the muffler welded it on? If so you'll need to cut it off...

If times are desperate a hacksaw cuts through exhaust like butter. You can get some exhaust parts at discount (advance auto parts), maybe pep boys -but autozone and bennett are devoid of exhaust parts.

Down here they stock a "flexible" exhaust pipe (tubo de escapo) that you can cut to size and fit 2 clamps on either side to bandaid back together the cut off portions. It'll leak, but it'll work 90%. 2 1/4" is stock for the tailpipes (muffler exhaust) if I remember right, and 2 1/2" on the muffler inlet.

 

how much do you think it would cost after towing to get it done by a perfessional... i may try the heat aproach tomorrow... what tools should i use to take it off after i heat the tube?

 

to do it right you will have remove the exuast (or at least the portion near the fuel tank) then drop the fuel tank....im sure ill be flamed for this but you can cut a hole in the deck above the fuel pump and change it that way...but then you have the hole to contend with...if you can, do it the right way...good luck..........tao

 

i've been thinking about doing the cutting hole approach but im thinking i'd rather go take it to a shop... is the rest of the job going to be this hard to do?

 

$300+ to have it done at a shop. My GF had hers done on her 82 pace car 5 years ago when it died on alligator alley. Good thing she had AAA, otherwise the towing would've been more than the work.

Basically you need to apply force to get 2 tubes that are likely rusted/corroded together. The muffler *should* be held fast by the hangers and support, so if you heat the joint at the muffler inlet (you should see where the metal of the exhaust joins the metal of the muffler, heat that up) - then strike the exhaust pipe at the 90" bend it makes on the passenger side. Twisting helps, but don't burn yourself. It really is a pain - most shops just cut then patch or weld it all back up.

 

yeah, thats alittle expensive... i figure i'll cut it tomorrow if i have too... just making sure i'll have enough room to work with if i just take off the muffler right?
THANK YOU for the help

 

also theres no chance of heat going through the gas tank and killing me is there? a new muffler from advance is 20 bucks and i doubt it comes with the exaust turn downs the one i got has... how much am i looking to spend to do it right?

 

LOL, yes actually there is.... just don't shoot fire directly at the gas tank and you should be OK. The fuel lines are on the driver side of the car.

 

Before Anything Else - make damn sure you need the pump. Have you verified that Oil Pressure Sending Unit is good, pump relay is good, fuse is good? Have you connected to grey wire and the orange wire in the relay wiring pack to see if the pump runs? Have you jacked up the rear of the car, and put ear to the tank to make sure the pump is or is not running? Many times you can't hear them unless you have ear on the tank.

If you know the pump is bad....

FIRST - make sure you have PB Blaster on hand - you HAVE to have it - it's $4 at autozone - nothing else substitutes - trust me! You'll need it for the stubborn rusted mud-caked bolts that have never yet been removed - spray them, and eat lunch, spray again, and try it, if doesn't budge, spray again, and eat dinner - get lights out, and try again - the PB Blaster will lossen them, sooner or later - just have patience and kleep spraying them.

SECOND - get a jack that will reach a height of 18 inches - a $19 Walmart jack won't get you there as they reach only like 14 inches - and you HAVE to have that extra 4 inches! - beg borrow steal a good one.

THIRD - Make damn sure you get a good brand/quality pump - and get the sock for it too - don't get an autozone/advance pump - get a Carquest, Napa, or genuine GM pump - we don't want to do this ever again!

FOURTH - drain/syphon every drop of gas you can from the tank - it's awkward and heavy enough without gas in it - gas weighs 8 pounds per gallon - it only takes 2 gallons to double the weight of the tank.

To get to the gas tank, your going to need to jack the rear of car as high as possible, while leaving the rear end itself as low as possible. Thus, you need jackstands, 'cause your going to need the jack on the rearend once the car is lifted. Jack under the rearend, careful not to jack the swaybar - jack it as high as you can get it. Put jackstands under the frame, just in front of where the lower control arms attach to the body. Remove both rear wheels. Then start letting the rear end down - to a point where the shocks are not compressed. Now, remove the panhard rod, and the track bar above it (also remove the thin metal shielding attached to body and trackbar). Next, remove the sway bar end links. Next, remove the shocks from the rear end (leave attached in car). Let the rear end down as far as possible without tearing/breaking the rubber brake hose on the driver side.

Exhaust - Now, go under passenger side and remove the bolts that connect the intermediate exhaust pipe to the cat. Go back to the rear and remove the supports for the muffler/tailpipes - there's one on each side - just remove the screws from the body. Now - wiggle the exhaust out through the rear of the car, twisting and such to work the bend in the I-pipe over the axle, and out. Now you have access to the gas tank, without disconnecting the muffler from the pipes.

Remove the gas tank door, and the plastic gas tank flange around the inlet. Go back underneath, and disconnect the lines to the gas tank - there will be 3 to disconnect (one with a coupling - 2 wrenches and 2 with rubber hoses), and a 4th with a plastic UFO looking gadget - just remove that gadget from it's holder in the frame. Disconnect the wireplug from the connector at tank. Now remove the two bolts taht hold the tank straps - watch your head. Wiggle the tank out, towards the pass side of car, and towards the rear - you may have to pull out the tank part way, then push up on the tank, to gently bend the inlet tube enough to work the tank the rest of the way out - the inlet tube wants to bind in the fender as the tanks comes out - after reinstall, you can rebend the inlet tube with the handle end of your rachet until it's straight again in the fender hole. Once tank is out, clean the topside with degreaser and/or brake cleaner to get the junk off, before you open the cam that holds in the pump assembly.

Tap the cam counterclockwise with a screwdriver and a hammer, until it is open, and carefully pull the assembly out (without bending the float arm - this will mess up your gas guage). Replace pump as per instructions (Make sure you get and replace the sock!) and reinstall tank. Reconnect the gaslines and the wire connector, and test the pump BEFORE you proceed - we don't want to have to do this again! If it works, reinstall eveything else.

Takes me 8 hours by myself - I'd dedicate a weekend to cover any problems (like stubborn bolts). I've done 2 in the last 6 months (on 2 different fbods). Let me know where you have problems, and I'll be glad to chime in.

 

A few tips that might help you.

When you drain out the gas, siphon it from the return line connection near the tank. The return outlet is in the same position in the tank as the pump is (very near the bottom).

Get the car as high up in the air as possible.

When the tank is finally loose, the real nightmare is getting the one piece filler neck free from the little hole in the body below the gas door. It helps to use a pry bar to lever the end of the filler neck past the little hole while someone else holds the tank from below. Don't try to pry it too much, as it might break.

 

thank you all soo much, im going to go by this step by step.... i'll have to read it again when i start but this is going to help me out more than the book... jesus christ thank you

 

12v applied to the G terminal will also bypass the relay et. al. to test the pump directly. How did you troubleshoot the pump failure?

You could also loosen the axle to drop it enough to slide the exhaust over. It's usually easier to loosen the pipe at the cat joint than at the muffler.

Whatever you do, don't cut into the hatch unless you plan on doing the lines properly and then closing the hole with a proper access panel etc., etc.

Yes, I'm biased.

 

Yeah man, just hack a huge ol hole in the car and cover it up with some aluminum siding and silicon. It will work great. Gotta love sarcasm.

 

Well, I've managed to diagnose that the fuel pump cuts on when the key is on. Replaced the relay with a coolant fan relay (the only one I had on hand, it looked identical on the outside). Now, when I start the car, the RPM's jump to about 3k, then drop to the point where it'll cut out ~500, and do that constantly until I cut the engine off. Are the relays identical? Am I on the right track?

The pump cuts on, so I figure the pump itself is functional, correct?

Looking to not drop the exhaust, rearend, tank, ect.

Thanks

Edit: and for the record, my twin brother (this thread creator) has been using my name to ask questions regarding problems we are encountering in this process. Not that it matters much, but for future reference, he will be posting under his own name.. thanks

 

OK - I'd say replace the relay, make sure you can hear the pump again, and replace the fuel filter. Fuel filter located under car, just about where lower control arm mounts to body, on driver side.

You'll need 2 wrenches to get it off without destroying the fuel lines. Open the gas cap and let it vent. Also, get a pair of vise grips - above the rear driver axle, you'll see the hard fuel lines going to tank - they have rubber hose connections right before tank - pinch the largest one gently with vise grips. Then get a towel, put under filter, and loosen connector on both ends - it will still leak alot of gas, thus the towel.

New fuel filter like $9 for this car - Relay like $4. Let us know.

 

I had just replaced the filter maybe 6 months ago, but ive got another lying around that i'll replace again to be sure.

The weird thing is, the previously considered bad relay actually makes the fuel pump cut on, however when starting the car with it in, it simply cuts out, as opposed to the fluctuating RPM's with the other relay.

Both will be replaced tomorrow and I'll let you folks know.

Thanks.

 

 

Hell - for all this trouble - just replace BOTH the coolant and fuel pump relays with new ones, and for the sake of it replace the oil pressure sending unit and fuel filter - both relays, filter, and the oil pressure sending unit should be no more than $55 - just don't get Autozone/Advance Auto crap - go to Napa or Carquest - I've had Autozone/Advance Auto relays and OPSU's die again in less than 500 miles.

The OPSU is about 3-4 inches long, has a three wire connector on the end, and should be above the oil filter.

If the pump works, it works - they don't give any warning when they go out, and they don't come back in after they go - so I'm relatively certain that the pump is not your problem.

 

There is a really easy way of replacing the pump if thats the problem, pull up the carpet in the rear hatch and cut a hole, i did it like three weeks ago and it worked out really well, it took me like an hour and a half, in and out, car runs great.

 

Was it a hack job or did you actually put in the trim rings, door/panel, flared fittings, etc. etc.

Or did you just cut a hole open hack the lines apart, connect them with rubber hose and glue the metal back together? Doing the access panel properly will take you LONGER than if you do it via dropping the tank and it'll be less work.

 

Actually was nicely done, if you got the right tools and know how its not bad, flare the ends of the fuel lines with the pump out, when you drop it in the fittings line up quite nicely. also cut the panel out, used a punch and flange tool to make a recess and cut a peice of sheet metal to fit inside. eight little screws and some silcone to secure it.

Not everyone in the world is a hack you know, and with the right tools and an organized tool box things are easier. but i guess it is all opinion, i mean when you start removing, and braking brake lines and other bolts that haven't been touched in ten years, you might start to wish you had done it another way.

 

*Looks at the header* Yep, still TGO, which means the chances of finding a hack job are in the upper 90th percentile. You'll learn that the longer you float around here.

No need to get offended and act like I haven't done a few dozen of these, 'the other way'. Actually the sad thing is, I probably helped on my first one before you were 6. Some of us can do it in much less than three weeks. But what do I know....

 

if you could read, it says three weeks ago, an an hour and a half of work

 

To the guy needing help replacing a fuel pump. Was ur car stalling on turns and massive decreasing in speed or at stop lights? Tryna trouble shoot my problem, before i dump too much money too many places.

 

madhatter,
Please Please Please....don't EVER offer me a ride in your car! I'd rather walk!

Make sure you purchase flame-retardent clothes! They just might keep some of your flesh in good condition when that knuckle-head driving an F-350 who is talking on his cell phone & chewing on a BigMac slams into your rear end. While your enjoying your extended stay at the Intensive Care Unit/Burn Center, you can reflect on the few hours you saved on the fuel pump change.

Kurt

 

BTW, if you get a new oil pressure switch, you might want to get the socket made for it it. Mine was a real pain to get to without it.

 

Haha, after reading the above posts, I'm stunned and amused my brother didn't take the hack route.

Even though I explained to my brother that the fuel pump functioned fine (even showed him by turning the key), he still took it upon himself to remove things while I was away.

The fuel tank guard (steel plating) was removed, along with the panhard bar. The exhaust was removed at the cat and dangled in front of my eyes.

Well this morning I began reconstruction. The various removed bolts were scattered throughout my front yard. Managed to find all corresponding pieces short of a self-tapping screw that went to the tank guard. Replaced the guard and moved on to the exhaust. Put the muffler back on the hangar hoping that the pipe to the cat would align perfectly. Wrong.

I then began the task of figuring out how the pipe's hangar fit into it's rubber mount. It was jammed at the top of rubber mount, but I realized it belonged INSIDE of it. So with much frustration, compounded with the fights I was having with my brother about the issue of the car, the jack stands fell.

Note: The car was positioned slightly at an angle, and the rear was on stands at the axle. There were no wheel chocks involved.

My face was between the axle and the muffler. Had I been 6 inches closer to the rear or front, I doubt I'd be typing this right now.

It is official, for me atleast, that I really have no business underneath of a vehicle. If I am, it will be of a task I have begun and completed. I now refuse to continue a task doomed at it's start.

I have a friend coming by in a bit, he has a '69 w/ a 396 and some ungodly iroc he's been working on, so I'd suppose he could lend a hand with a little exhaust work.

QUESTION:

typed in caps for thoes of you who don't have the time to read a horrific story.

Will I be able to replace the panhard bar with the car on four wheels? I assume so, as the only difference between now and before I almost got my head smashed was the weight being supported by the stands. I figure it'll be more of an issue of whether or not I'll be able to crawl that far under the car.

Also, what would constitute as a "bent" panhard bar? It seems as though I've got a few kinks down the bar. The car shudders at speeds of 85+, so might I have inadvertantly diagnosed that problem with my potential death?

Just trying to find a silver lining in the whole situation.

Thanks.

 

Nope, as far as I know (my brother was driving, only person to experience what had happened) The vehicle just died while driving along the road.

The OPSU purchased was of the autozone brand, and to tell you the truth it was replaced roughly 500 miles ago. Again, my brother and a friend of his replaced it using pliers. 'nother note to self: don't let anyone touch my car except me. While changing the oil after the unit was replaced, I did notice quite a bit of oil. Once I get everything buttoned up reguarding the exhaust/rear end. I will replace the relay and filter, and if that doesn't do the job, then I'll be replacing the sending unit.

Just thankful that it's not the pump itself.

Shookum, i'd suggest having a friend turn the car on the "on" position, instructing very carefully not to crank, and put your ear up to the rear, as close to the tank as possible. That's how I found out it wasn't the pump.

 

If you understood the English language and knew what contextual reference was, you would have understood it was an exaggeration of the time it is alleged it takes to do it properly. Try again, mmkay.

Just in case you still don't get it I'll spell it out for you. You nad everyone else that complains about the TIME it takes to do it right, or how much time you allegedly save doing the access panel properly, have no damn idea how long it really should take to do it the way it was supposed to be done.

And BTW, to do the access panel properly, you will need much more time than an hour and a half, you are full of crap... or maybe crack, coke, amps, etc. if you flew threw that project that quickly.

 

I've managed to find a ride to the parts store to get a relay and a filter and I'm posed with this predicament: Should I go NAPA for the relay or Autozone/Advance?

Main difference that I see is that Autozone costs 10.99 while Napa costs 15.69.
Upon searching on the napa site, it seems as though the relays are identical to the cooling fan.. correct?

How long should I expect the GP Sorenson relay to last?

Thanks.

 

I won't buy anything sensor/electrical related from autozone/advance ever again - I'm tired of changing them out every 30 days! Go Napa - it's $5 - eat a bologna sandwhich tomorrow instead of that happy meal!

 

Well, I finally ended up getting to the fuel filter. Replaced it without O-rings, as I actually ended up losing the other ring I had replacing it, but figure if i can get the car running again.. well then I'll just replace the rings (and experience the fun of gasoline on my arm once again).

With the fuel pump relay I currently had in at the time everything messed up, the fuel pump turns on, however when I start the engine, nothing really happends, short of a quick rev and silence. When I replaced it with the coolant fan relay (a known good, i suppose), the car will start, injectors spray in their conical, regular way, but the RPM's jump from ~3k to just about cutting out.. Does this for about 30 seconds (without gas), and then dies. When it dies, fuel will spout from the top of the injectors just a bit.

I guess I know the next thing to be replaced will be the Oil pressure sending unit. Could any of you tell me what the symptoms of a failed unit would be? Especially an autozone brand.

I'm not looking forward to crawling under the front end, but if it gets me out of working with the rear for a bit, I reckon I can live with it.

And in conclusion: The exhaust never sounded meaner emptying after the cat. Now if only I could get the car running so i could get that fixed.

Edit.. camaronewbie, it's sort of ironic i suppose, but I actually got my camaro from cary area... sanford to be exact... got "family" around there. Brick capital represent.

Edit x2: To avoid spending more money than is necessary, would anyone know if autozone loans out the socket to pull/replace this switch? I don't like how my brother used pliers and whatnot to install the other one. I'm guessing a universal O2 sensor wrench would do the same job the socket would? I wonder if AZ would loan that part.
http://www.autozone.com/servlet/UiBr...EGRN%7C%7Etrue
Loaner wrench means it's loaned out? not too familiar with the service.

 

im having the same problem with one of my camaro's. i have a 90 IROC 305. i replaced the relay, and also tried to "jump" the wires to see if the pump works, but i get nothing. i guess ill try replacing the opsu, but if that fails, i noticed someone talkin about replacing the sending unit? if so what and where is that located?

one more question, i believe their is 3 cables going to the pump, 1.black 2. purple 3. grey, well i checked the cables for current using a tester, and only the grey cable turns on when the key is in on position. i know the black is ground, but what about the purple one? should this one have current to?

also as for the opsu i would notget the autozone brand, i replaced one on one on my camaro's and it started leaking and loosing pressure after about a month!

 

the sending unit everyone's talking about is the oil pressure sending unit.. opsu like you said. I would have found out if the opsu was the culprit, but I couldnt get the 3 ton jack under the front crossmember... I'm a little reluctant to jack from the control arms, much less one side at a time.. guess i'll be searching about that issue later.

It doesnt seem like too much work to simply diagnose a faulty fuel pump.. until it happends.

 

Jumping the large orange wire and the brown (or grey I also heard it called) wire in the relay IS the test for the OPSU. If you jump those 2 wires, and the pump works, then the OPSU is bad. If nothing happens, chances are the OPSU is good and the pump is bad.
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Can you get the jack under the front, between the tire and the air dam, from an angle? If so, get it under the round part where the front coil spring is - that's a good jacking point - you get that corner of the car off the ground to get where the filter is and the OPSU.

 

I was under the impression that jumping the orange and gray wires were to only test to see if the relay was bad. I jumped them anyway, and as soon as I did, I could hear the fuel pump turn on. Stayed on, after i started it, it did it's usual going to 3k rpms and almost cutting out, over and over, then eventually dying.

If i'm not mistaken, at this point.. after replacing the relay and filter, and hearing the fuel pump run, then I'd have to be confident that it is indeed the opsu.

I will jack up the car today, and work on it tomorrow, and hopefully I'll breathe life back into my maroon beast.

If that wasn't the test for the opsu, IS there a test to find out if it is bad? Search didn't come up with anything definitive, except that the orange + gray wires were to see if the relay was bad.

Thanks.

 

I spent a little more time searching and came across your request for a wiring diagram, camaronewbie. Looking at the diagram, I see that it does indeed jump the opsu. thanks for the info.

I wouldn't think that the fuel pump would be bad, when I can hear it operating.

Looking at the wiring diagram, I see that there is a 20AMP fuse going in-line from the opsu to the ECM. I had considered there might be a problem with the ECM getting signal from the fuel system, so this might actually be my ticket out of this problem I'm facing.

Any Idea where this fuse might be? Diagram says it's an orange wire.

In any case, I'll keep you folks posted.

 

I found the inline fuse. For thoes who might come across this thread in the future, it was found to the left of the battery, mounted to the driver's side fender. The fuse itself is good.

I'll have to wait a day to check the opsu, as it is raining here. I am now posed with two questions:

When I crank the motor with the relay jumped (gray and orange), the RPM's will jump from nearly 3k to cutting off, anywhere from 4-10 times without gas applied. Would this be a sign of a bad fuel pump at this point? I hear it on, I would imagine it functions.

Is jumping the relay the definitive test of whether or not the opsu functions? I'd imagine that if the opsu was bad, even this jump would fail as the orange wire wouldnt be making a connection with the other wires in the opsu, although this is only a guess.

Thanks.

 

The oil pressure switch/sending unit and the f/p relay work concurrently. One can fail and it will not effect the actual fuel pump function unless they both fail. Applying 12v to the G terminal of the ALDL or using the diag wire in the 90 up models will bypass both.

It's not too hard to diagnose a faulty fuel pump. Jump the G terminal look at the pressure. Start the car and drive it while watching the fuel pressure. Make sure you have no issues with your fpr and you have your answer.

That said, the fluctuating rpms don't sound too good for the pump, however, without actual pressure readings it would be technical guessing at this point. You need to monitor the fuel pressure.