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zordak New Reader
12/5/16 7:11 p.m.

This is going to be a long story about my 91 Firebird. It started a year a go when I was looking for a 3rd gen Firebird on Craigslist. I came across an ad for a rust free 91 Firebird Formula with 156000 miles and a hesitation on starting off from a start $1500. I watched the ad for a week or 2 and it stayed up and even got updated once. A phone call arrainged to look at it after work. I found a white 1991 Firebird 305 TBI automatic with T tops and the ground effects body work. It ran and moved under its own power and stopped. I offered $1000 hoping to get him down to $1250 and to my surprise he took the $1000. I gave him a deposit and set up to pick up the car the next night. I had the wife meet me at work(closer to the car than home) and drive me to get it. After concluding business and airing up the nearly bald tires and jump starting it, I headed for the nearest gas station to put gas in it(the PO poured in 1 gal. to get it started the day before)while he ran back to his place to get the second set of keys. On the way to the gas station I find out the brake pedal effort is high and the car pulls right under braking. While waiting idling the car it springs a leak in the upper part of the radiator. While examining the problem the PO shows up with the extra keys. I use the gum trick to slow the leak down and head out for 75 mi trip home. On the way I discover the temp gauge does not work so I had to use the lack of heat method to determine when the fluid level dropped enough to warrant a stop for more fluid. Oh yeah the small hesitation turned out to be bad enough to stall the engine if I did not press the pedal carefully. I got it home without cooking the engine or other incidents. Here are some recent photos of the car.

After getting the 'bird home I fixed the brakes and yes it was a bad drivers side brake hose. A new radiator for a 350(future upgrades in mind) solved the leak. Now on to the hesitation, first I tried the fuel pressure regulator on the TBI, better but not fixed. Next it was the EGR solenoid and making sure the EGR valve it self was functioning properly, then all the vacuum lines, and then getting an ALDL cable and and checking the computer for proper function as well as the sensors, all ok. By now all you who now anything about TBI are screaming why the bleep didn't he check the bleeping fuel pressure. In my defense I have not yet run into an electric fuel pump that just reduced pressure, in my experience they just die. So after getting a fuel pressure gauge and the proper adapter to fit to the stock fuel lines I find that even when pinching off the return line I get 8 lbs of pressure. So now I come up with a plan because I know I have to remove most of the rear suspension to get the fuel tank out. So I order a 350 TPI fuel pump(more pressure bolts right in, again prepping for future upgrades and the TBI regulator will still keep it at the 12-15 lbs), new rear shocks(the ones in it looked original) and replacement rear control arms and panhard bar. By the way it was a bad hose connecting the pump to the gas line. Sorry for the bad pics.

After installing the above and not having to drill out ANY screws(the under side is really clean), Now I have a drivable car. Well that and cleaning the interior to get rid of the funky smell and a new set of Toyo proxes tires in the stock size. Now that I can drive it I notice the front brakes lock up a little early. After checking out the rear brakes. I found the PO had a salvage yard rear end put in and the shop that did it did a really pour job on the brakes. They wrapped a replacement brake line all the way around the axle instead of cutting and flaring it to length, also not hooking up the parking brake. So after replacing the rear lines, slave cylinders and some parking brake hardware, I had the brakes sorted as well as stock brakes could be. Ok I now have a nice running T top car to run around in for the summer and do just that. I like driving around back roads with the tops off in a strong running well handling car. After renewing my subscription to GRM I find an ad for the SCCA Track Night and lo and behold they are doing one at a track a half hour away, Cool. I go through the car determine every thing is up to snuff and go out to have a good time. I found the people running it to be pleasant knowledgeable and had a great time re-acquainting my self with high performance driving. By the last session I have stopped trail braking. I was entering turns to fast and getting on the gas late on exit, and am braking earlier harder and am on the gas through the corner and getting quick exit speeds. On lap 6 or 7 at the end of the long straight I end up boiling the brake fluid(Yes I used DOT3 instead of DOT4 my mistake) any way I back off for the rest of the lap and get off without incident. The brakes come back after slowing down and not using the brakes as much so I can get home. Once home I replace the front discs with PowerStop's street pad and rotor kit and the rear shoes with their heavy duty stock replacement shoes. next I try to bleeding the brakes with DOT4 fluid I had a funny feeling pedal. After replacing the master cylinder and several re-bleeds still the funny pedal. So no leaks and a pedal that feels like it starts braking at the normal height it mushes to the floor but will not pump up like air in the system. Now it I find out it is a proportional valve and not just a warning light switch so I go looking for a replacement. No luck, anywhere. So a Wilwood adjustable valve, the one I chose has 1 in and an adjustable out for the rear and 1 in and 2 outs for the front so with the right adapters and using the stock valve mount problem solved.

Now at the track I notice a lot of body roll in the corners. The front rear balance felt good just the body was rolling an uncomfortable amount. Now a look at the GRM website pointed out that a lot of good suspension goodies came stock on some 3rd gen f bodies. A calipers showed I had middle of the pack 30mm front and an 18mm rear. Back to craigslist. Someone in town here was advertising new in box subframe connectors for a bout half price so I picked them up. Then I came across an ad for chevy parts and in it was the disirable 36mm front 24mm rear and the wonder bar front stiffener for about a third of what other ads where asking so for a total of $160 I got $500 worth of stuff.

So over Thanksgiving weekend in it went.

The subframe connectors came with grade5 screws I went to the hardware store and got grade8. I also replace the end links with AC Delco units sourced from Amazon(new got to place of inexpensive car parts). Now the 'bird corners flat. I can't wait to see if the Track Night comes back to the near by track. Next on the agenda is new front shocks, then figure out a proper power plant for it. I would really like to go with an aluminum block LS but the budget won't go that far. I really like the looks of the TPI manifold but in reading about them they produce good low end torque but at a sacrifice of top end horsepower(start wheezing around 5000RPM). LT1's are the right price for everything to swap in(engine, trans,accessories and computer and wiring), but I do not like the distributor setup or the reverse coolant flow through the block. I might end up building something on the cheap with a modified TPI intake. No money right now not much in the near future because of a medical scare a few weeks back. Several thou to find out my heart is in great shape but I had a bad lung infection. So I keep thinking and reading for now. Thanks for reading.

Chadeux HalfDork
12/5/16 7:26 p.m.

Pics don't appear to work, but my unscratched 3rd gen Firebird itch has me very interested in this story.

Gearheadotaku PowerDork
12/5/16 7:44 p.m.

When you replace the front struts, get a set of moog 5660 front springs. cheap on Rock Auto. Your front bump stops are probably smashed to bits, spent the 10bucks on a fresh pair from Dorman. My '91 made it to the top 10 in the 2014 challege with 305 power. Great cars!

zordak New Reader
12/5/16 7:48 p.m.

In reply to Chadeux: fixed the pics

Opti HalfDork
12/6/16 9:19 a.m.

Buy a cheap l98 and then just put an lt1 intake on it. The Lt1 intake is actually a pretty goood design, and people have been adapting then to conventional sbc for quite a while.

zordak New Reader
12/6/16 9:40 a.m.

Thanks for the advise. Right now it is winter and they use a lot of salt up here so the 'bird is going to sit and I am going to work on some small projects like fixing the drivers side map/cup holder and probably making a drivers side front air dam. The ground effects were trashed on the left front but someone is re-popping them so a little paint and a couple of hours fixed the ugly. If the budget permits may be fix the drivers seat, we'll see.

AClockworkGarage Reader
12/17/16 7:30 p.m.

Looks like a great start for a project. A lot cleaner than mine.

zordak New Reader
12/27/16 5:53 p.m.

I had a little time and decided to work on the map pocket. a trip to the hardware store resulted in a nylon washer and spacer some super glue and jb weld and hopefully once it cures it will stay together.

12/28/16 4:55 a.m.

Welcome to the board. 3rd gens are great projects - congrats

Mad_Ratel Dork
12/28/16 6:53 a.m.

every one of these threads has me hankering for one of these. but I want a manual damnit... which apparently add a few thou to the price?

zordak New Reader
1/3/17 11:38 a.m.

After a little rework I got the map pocket done and installed. I have been looking around for engine choices, looking at the HorsePower's lean green machine build where they spent around $1000.00 getting 30 or so RWHP. and the later IROC build where they swapped out the TPI 305 for a carb on a 350. I am thinking of swapping in a vortec from a 96-00 truck using engine trans and ecu. I will adapt the current water temp and oil pressure sensors to keep the gauges working. This way I can use OBDII tuner to compensate for any future updates. I have seen a few on craigslist cheep from abandoned projects. I want to keep the advantages of EFI. I am finishing the upgrades to my hobby CNC mill so I can sell it to finance a different engine.

zordak New Reader
1/15/17 7:49 a.m.

Just a quick note I picked up a different set of front seat belts from ebay. The ones on the car are looking a little fuzzy on the edges so when the weather warms up I'll swap them out.

zordak New Reader
2/19/17 12:15 p.m.

With an unusual bit of warm weather I was able to get a set of kyb front struts installed. Sorry no pics. I am fighting off a really bad bug, had it for 2 weeks, according to others who've had it it is another week or so to feel normal.

Spinout007 UberDork
2/19/17 1:16 p.m.

Love it man! My first car was an 86 IROC. I miss my mullet machine!

Pattyo New Reader
2/19/17 1:28 p.m.

In reply to Opti:

What is the advantage of the Lt1 intake?

Dusterbd13 PowerDork
2/19/17 1:58 p.m.

Much better power curve. Essentially the miniram for the l98.

Pattyo New Reader
2/19/17 6:42 p.m.


zordak New Reader
2/26/17 1:34 p.m.

Craigslist strikes again. I found an ad for a possibly rebuilt 305 TPI engine (maybe out of a firebird ) for $250. It came with the TPI intake (IMHO one of the best looking intakes around) and ECM and wiring harness. PO said it had been sitting for a few years. When i went to get it I used my new USB camera(christmas present). The camera is about 1/4" diameter with LEDs and on about a 3' cord. Pictures are not the best, it has about an 1" to 1-1/2" focus length, but on the cylinders with the pistons were down, I could see reasonably well and saw some flash rust on top of a decent crosshatch. Oh well if the ring end gaps and piston clearances check out a little light honing should clean it right up. I will also check main and rod clearances and check to see how the bearings look. The draw backs here are that the motor did not come with the rear main seal housing or an oil pan. And yes that is a remote oil filter adapter on there. I hope to turn that into some cash to help the budget. And here is the other stuff. And again there is a third set of runners so may be I can turn that into some cash. I know I said earlier I would like either LT1 or LS power for the 'bird but money is a little short right now and I still think the TPI manifold is one of the best looking ones around. Horsepower wise just going to the TPI from the TBI is around 30HP. I plan to do a little port matching on all of the mating surfaces and some polishing in the long runners to inprove air flow. Add in a decent air filter and large diameter piping to the throttle body and headers and 3" exhaust I should get between 15 and 20 additional horses. Well when the weather gets warmer up here. I will get on cleaning up the garage and starting on the engine.

Crackers Reader
2/26/17 1:53 p.m.

I agree, the TPI intake is about the best looking OEM manifold ever bolted to a SBC.

It's my understanding the lower intake doesn't flow well at higher RPM's though. It'd be cool to cut one up to see how much they can be opened up.

zordak New Reader
2/27/17 9:32 a.m.

I took a quick look at the lower manifold and there is not much space between the ports, 3/32" to 1/8" I think. I am going to try to do a really good polish/match job on it to improve the top end flow. Remembering my 89 T/A it took off from a stop really well.

zordak New Reader
3/6/17 9:36 a.m.

I ordered the rear main seal housing and oil pan from ebay over the weekend. I started to clear work bench space( never ending struggle not to cover every flat surface with stuff). I also got the CNC mill working and listed it on ebay. Here is hoping it sells so I can finance some more stuff for the car.

zordak New Reader
3/9/17 9:35 a.m.

The rear main seal housing showed up last night. It was listed for a marine engine but I did a quick check and it matched the gasket and a check with a calipers showed the right seal size. I also finally found the left front air dam on ebay and ordered it.

daytonaer HalfDork
3/9/17 9:48 a.m.

When I had a 350 tpi I remember reading the intake was designed for a 305 and adapted to the 350: thus the claims of no high rpm power are mostly based on stock 350 setups.

I'm pretty sure valve float was my high rpm limiter, not the intake....

I'm sure you will love the tpi intake.

Also, those grey Delco injectors tend to die. I replaced them with Ford (Bosch) 4.6 injectors, I forget what color but had similar flow rates when the Ford pressures were changed for GM pressures.

QuasiMofo MegaDork
3/9/17 5:02 p.m.

Iirc 1989 Ford Thunderbird SuperCoupe injectors worked reasonably well here too.

zordak New Reader
3/10/17 9:33 a.m.

Thanks, seeing as I did not get injectors with the motor, new ones it is. I am going to try to brave the weather (33 deg sat, 38 deg sun) and start with removing the valve covers and check casting numbers on the heads to make sure they are the right ones. Then figure out a degree wheel to check the cam.

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