They aren't the easiest thing for future owners to fix. My vert I purchased in dec. had a VERY sloppy access hole cut and no cover fabricated for it. As clean and solid as this car is the only option was to fix it right. Some of the welds are still visible. I wasnt all that worried with the aesthetics once it was good enough since it wont be seen.

To get a patch from a donor, square up the patch, trim hole for the patch, weld it up, grind, and paint it takes A LOT of work and quite a few hours.

Don't do it, its easy enough to drop the fuel tank to do the pump or sending unit.

 

Forgot one, this repair would have been MUCH harder on a hard top/t-top car. At least this one doesn't have a roof to get in the way while working.

 

There's nothing wrong with an access door if it's done right.

 

Whick 95% of people doing em, dont do.


Do it right and drop the tank. I will be honest, with my old 92 Camaro with 160k and rusty to crap I did struggle to drop the tank but after doing it and finishing every bolt with anti-seize, the next time I dropped the tank in less than 35 mins. On my 86, I did it in less to install a Walbro 255.

Do it the right way or don't do it all imo.

 

I'd never cut a hole in mine, however if it already had one I don't think I'd permanently close it back up. If you have the lemons, might as well make lemonade (make a door).

 

I went under to change mine I will never cut mine took 5 hours my self to do second time 30 mins or so lol

 

I have one in my car and it doesnt bother me to have it there or not. I find it easy if I had to use it in a situation. I leave my tank full at all times and 60L of fuel isnt easy to handle when your dropping a tank. I dont mind the door and its all in personal preferance

 

What people don't realize about an access hole is 2 things. Not only are you cutting a hole (that in itself wouldn't bother me) but you also have to put a second splice in your fuel lines. That is 3 possibly sloppy fuel leaks. I realize some people do it clean, but chances are if your to lazy to drop the rear, your probably to lazy to cleanly cut the lines and splice them back together in the limited space you have.

secondly, the major one you won't realize until its to late... In a rollover you better hope that O-ring was installed 100% and also not compromised in the crash. Leaking fuel will make it past whatever weather stripping you have installed (if any) on your trap door. Especially if it is already on fire. Chances are you are pinned in a rollover... maybe dead or unconscious (especially in my case, a vert) but man would it suck to be alive and thinking sh**, if I had just done it right I wouldn't see that fire rolling out of my trunk right now.

Lastly is future value... My Z is on the higher end of the value scale when it comes to everyday thirdgen models. Convertible, relatively low miles, great interior... everything. Had I thought to check under that carpet before I bought it the seller probably would have lost a deal.

 

Lots of cars in many different brands come from the factory with an access hatch above the tank for fuel pump and filter access. They are not killing people all over the place with fire creeping into the cabin, etc. If it is done right it will be fine. If done wrong well yes it could be an issue.

I always find whole debate very ironic. People go on and on about how to improve the car by welding in frame connectors and modifying the suspension and chassis to fix what GM did wrong. Then when someone cuts an access panel to fix something else GM did wrong it is blasphemy. If you have a mint car that is completely unmodified, well keep it that way, if you have already hacked it up with frame connectors and such, well what is the complaint?

BTW, my Camaro does not have a access panel (it is carbed), I would have no issue adding one if needed. All my other cars do, from the factory.

 

Friends don't let friends cut up a clean third gen!
I have even seen lazy hacks do this on pickup truck beds. Take a couple hours and do the job right people!

 

If you do a good job and seal it right it's not an issue, And as for the value, These cars are never going to be worth what a first Gen F-body or any other 60's-early 70's muscle car that command outrageous prices on the tv auctions that everyone loves to watch get anyway, The third gens just don't have that pedigree. So do what you want to them. If I had looked under the carpet when I bought my 92 T/A vert and saw an access hole I would have said sweet it will save me the hell of pulling the exhaust and dropping the tank when the fuel pump inevitably fails, I would look at it as an improvement, but thats just me..........

 

If you want an access port, by all means do it, its YOUR car, Noone elses. Just do it right. It can make life easier if things are done right.

 

Ok, on my TA I will not cut the hole, but I sure would on my Camaro. Oh and if I bought a car that had the hole and it was not done bad I too would have thought sweet easy work for me down the road. If I had the hole there is no way I would have welded it shut like the OP did, but hay-it's his car. Also when someone cuts and fabs a crossmember to run duel exhaust I don't hear people telling him he's a hack job and the car is killed now and like was said people weld on SFC's it's not a hack job.

I know that when the 3rd gens came out they had a carb only, but I know GM knew they were going to EFI so why would they not make the panel? I mean the process that you have to do to drop the tank is crazy IMO.

 

Maybe its just me but, if I am selling a car and the "buyer" comes around and starts tearing out the interior "to look for any imperfections or hack jobs" I might have problem with that.

These cars are coming up on 30 years old, chances are they have had multiple owners (Im the 9th owner on mine). Each owner does there own thing that they think is best for the car in there opinion. Its all a matter of opinion to the particular owner.

Personally, I would love a trap door (done right) because my exhaust is completely welded together. I would have to cut the exhaust out to remove the tank, then get it welded back in.

 

I prefer to drop the tank because I am able to clean out the tank real good and replace aged weathered rubber parts ect.

 

I've had an access hole in my 88 for a few years now and I'm more than glad that I did it. I can swap my pump out in literally ten minutes if I need to compared to 3 damn hoours on the ground swearing at the car.

 

I wont cut into my 89, but my RS that didn't run when I bought it, already had one and holy jeez did it make diagnostics easy. I do need to make a cover panel for it, but I like it.

 

DSPO did it to mine, which honestly I would be okay with, however they hacked it up pretty badly, I plan on fixing the hack job but I may or may not put a trap door on there, it depends on how I feel at the time, min is a 91 RS, that currently has a 305 tbi, that needs to be replaced. So it will be getting a carbed 350 or 400 in there to get rid the crappy tbi

 

it only takes a few hours to drop the tank the correct way to replace the pump.. Those access holes are for hacks.

 

PFFFT. That is nothing compared to the car I just picked up!

 

Its so true. Its just a hack for lazy people. If someone can't spend the time to just do it right, they shouldn't be working on cars.

 

Mine's worse I will post pics tomorrow

 

Hacks? Lazy people? There are MILLIONS on cars on the road with fuel pump access hatches that wouldn't be called "hack jobs". Done properly an access panel will work just fine. I don't consider myself or others who have done this cleanly to be hacks or lazy. Work smarter not harder.

 

If I was to do a door it will take me much longer tha to drop the tank. I would replace the lines I cut with nylon hoses flare the ends of the lines so they can be screwed on. That would be the right way anything else I wouldn't do. Even if a customer car has one I will still drop the tank.

 

vast majority of the doors are hack jobs and rubber hoses splicing the fuel lines back together. You might get a good seal on the fuel lines but you never get them to what they were before you cut them. Anyone who cuts a hole in there car and splices fuel lines together with rubber hose is a hack. Yes you can make a pretty door but you cut a hole in your car!!!!! If you just drop the tank you haven't swiss cheesed your car. Some ppl might not call it a "hack job" but I do. IMO

 

Well everyone has their own opinion but as I said, if done properly it works just fine. I've dropped MANY a tank out of these cars to find a better more simpilifed way of replacing the fuel pump. My car isn't a daily driver and I beat it up hard on the corners with no signs of wear from the access panel. To each their own.

 

Shame on GM for such poor design and engineering. My old BMW 735il from 1991 and 735i from 1989 had access panels in the trunk. It would have cost maybe an extra $2.00 in production costs. I cannot imagine doing this job with no lift. drop the rear, exhaust, tank. Don't know what they were thinking.

 

I was always against it but boy am I glad I did mine. Had it open twice in the last 2 weeks. Once to swap the pump. Second time it was on the dyno losing fp. Had the pump out in less than 5 minutes while still strapped down to check for any splits in the feed hose. I’ll be popping it open again tomorrow so I can put in my twin 340’s. Obviously my car is modified so not having a door is pure insanity. On an all original car its really not needed, and most of the time not wanted.

 

I don't have an issue with adding a factory one from a donor car...one that is designed and tested to stay sealed in a crash. Properly cut and welded into the axle "hump", it's as good as if it was made that way. Ones made with a can opener and sealed with duct tape, not so much.

 

I've done it two times. The last time two weeks ago on a buddys car with just two jack stands. Took me about 5 hours of unhurried work. It's not a big deal imho.

 

I just welded in the DSE unit which comes with a beefy flange. Coated in seam sealer and ready to go.

 

It is NOT a "poor engineering design". This area of the car is in the crumple zone and if you got hit hard enough in the rear fuel WOULD DEFINITELY get in the car with an access panel. Watch the NHTSA video of the 4th gen rear ending video, then you'll want to weld your panel back closed.
The problem is there is no "doing it right" when it is in the crumple zone. The floor is literally a firewall in this location. It is a safety issue.

Have a racecar? Do it. On a street car, just drop the tank, it doesn't take nearly as long as you would think. I did it three times in the street now, I am in/out in under an hour.

 

I don't mind dropping the rear axle (it's not hard) but I'm not looking forward to dropping the exhaust...

 

These cars were designed in the mid to late 70s, a tad bit before the EFI and intank pumps were a thing. Sooooo not adding a trap door would most likely be a cost saving thing. I'm sure crash testing a ton of cars and changing a crumple zone sheet metal isn't cheap.
If you notice, most cars with a factory trap door, they are in the safety cage area with fuel tank under the rear seats and not in a crumple zone. There are some that aren't too.

 

I agree that it's unfortunate there wasn't a better design for replacing the fuel pumps, it is really more difficult. I can however assure you that it's a lot more than a couple of dollars of production cost, and it's a huge safety issue. Keep in mind a few things:

• Late 70's had a lot of attention on rear end collisions and fuel tanks - go back and look in the newspapers of the day. Certain cars had the gas tank as the trunk floor. Manufacturers were upgrading designs to improve this area.
• There was incredible pressure for emissions and fuel economy. American manufacturers were retooling their entire product lines to meet "27.5 MPG" CAFE standards and every gram was important. Just adding the bolts for a hatch could have put the body engineer over his mass target.
• You really should consider the cost of changing underbody stamping dies. Those dies are very large, heavy, complex and expensive to change. That is the last part that the vehicle team wants to change.
• There was no CAE and computer aided crash testing like today. You really did need to run crash tests. By 1990 that was beginning to change. Today, nearly all that design is done by analysis and crash tests only confirm that the analysis is correct.

As far as doing it without a lift--yes it's not fun. But, I have done it (alone) with 2 pairs of jack stands (second one for back up to the first), one good floor jack, and a half-dozen 2x12 wood blocks to place under the rear tires to be able to reset the floor jack when dropping the axle. Siphon the tank out first. It just takes a little patience.

 

I can see both sides to this discussion I just did pump, hanger and tank in my 90 it was dead because P/O hacked in big Bosch pump - I had to start from zero but I'm glad i did my car doesn't have exhaust yet and I have a lift good thing P/O didn't cut a hole but the DSE Access Panel HERE would be the only way to do it
why will drop the tank- is I don't want to cut the lines and band aid it All I have seen are spliced with rubber hose is it F/I hose? or regular gas line who knows, some know what they're doing some do not. IF i were to splice the lines the pressure would be with a compression union.
Whats amazing to me is how many third gens are sold, parted or parked because of dead fuel pumps probably because people wont or cant change a $10 fuel filter regularly

 

I see both sides as well. Mine is unmolested. I don't mind dropping the rearend; I've done that before, but I really DO NOT feel like dropping the exhaust...

 

There isn't a right or wrong perspective here, do what you need to do. There are definitely wrong ways to do it. If you do it, you must put a steel frame around your tank, and around your opening. The fasteners must be of sufficient strength and quantity. Having one done properly does not have to relegate you to the pinto safety standard. Rear end impacts are not standardized, every one is different, and no matter how good you think your tank is protected, there is a type of crash that can open it.

 

Ironically this is the same argument for doing the access "right".

 

This debate always ruffle feathers. I see no point in telling people not to do something to their car,its going to happen if they want to do it. Long ago the major argument was that cutting the hole lead to stress cracks near the shock mounts. Now its roll over safety of gas getting into the cabin from non rated seals even if done "right". Or people are considered hacks for doing in the first place because they dont want to drop the rear,the exhaust and tank down.

Lets be real..most stock cars will probably not need to go this route for the odd time you will replace a pump due to age/mileage of the car your going to do the normal remove everything properly and be on your way. For modded cars on the street/strip side of the fence its very useful and they are alot better ways to make this a safe clean non hack mod for situations where testing pumps or changing them is done easier. Mine is very similar to LsxMatt where I used AN fittings on the lines, made a quick disconnect plug,trap door with windshield molding and seam sealer.My car is also caged,subframe connectors and a very heavy dana s60 in it now.

I had a stock pump die on me on the highway when my other car was a 355 tpi, car towed home, full tank..dropped everything in the driveway,bought a new pump, 3 times in a row I was given tbi pumps in the wrong packaging before I got the car back together.If I didnt have a pressure gauge on my car and just called it good after putting in the new pump,Id be pissed to drop it all again for another removal for a 5 min pump install.Ive had a 255 walbro give out on the dyno just after i went turbo and made a quick change to a 450 pump on the spot. Ive had a pump give out at the track and I definitely wasnt dropping a rear to get home.

I keep a perfect bag of common hand tools and spare parts for situations in the back left compartment. Fuses,belt,spare pump,tire plug kit,qrt of oil, etc and fire extinguisher,emergency light. Because streetcar!

 

So true, This is why I don't even bother getting into these discussions. Don't listen to anybody's suggestion, it's your car, do what you want with it. If it's valuable, then perhaps reconsider for the next guy. If its a track car, missing title, etc, then have at it. As for structural integrity, a simple visit to any junkyard where accident / damaged vehicles are towed will show anyone that the strongest of vehicles can be torn open like aluminum foil when hit hard and in the right spot. Also, if the car was flipped over during the accident, and we're talking T-Top shattering or windows shattering, or were simply opened during the accident with the driver knocked out, I don't think the non cut third gen will save them from any leaky fuel...

Anyways, argue on...

- Rob

 

You mean a hit like this? Dude in the S10 hit me going 60mph while I was stopped at a light on the Hwy on my way home from work.This the first of many third gens that I've owned and yes that's a 20 year old me in 1998 lol!

 

How bad was the whiplash?...

 

Pretty bad. Had I not been wearing my seat belt and if I would have hit the car in front of me harder, my head would have hit the roof of the car and probably broke my neck. However when the seat broke and I went back the seat belt caught and I didn't go forward too much. I spent a night in the hospital for observation, ended up with two herniated discs, and had a couple of lovely red marks across my chest and abdomen for two weeks afterwards.

 

A consideration in fuel tank packaging is whether the areas likely to contact the tank in a crash are "friendly" or likely to contact and tear or puncture the tank. Watch out for protruding bolts and sharp edges if you're making modifications.

 

very good point, personal experience?

 

Yes, just experience from many years in vehicle development, mostly powertrain. I often had a system level view. I wasn't directly responsible for fuel systems or crash analysis, but I worked with those teams and heard their concerns as I was integrating my components into the vehicle. If one of my parts didn't meet a requirement in a crash simulation or test, I would need my team to correct the issue. Several times we needed to add shielding or relocate / reorient components to meet targets. These areas are quite complex and there is much more than meets the eye of the casual observer.

 

Hate to see such a beautiful car end in that way, but glad you're still here with us to tell us about it.