jiyasa

iTrader: (1)

I have a 91 3.1L V6 and nowadays it seems like our FI cars fit that small bracket where the older mechanics don't know how to work on them because they aren't carbed and the newer mechanics use the OBDII system where you just hook it up to a computer and it tells you specifically what's wrong. With our cars everything seems so vague and no one seems to know how to work on these OBDI cars. At some point or another I'm sure you guys have run into these grey matter electrical problems (especially the 90-92s) and you obviously pulled through it. How have you guys dealt with this problem?

I really would prefer to keep my V6 but if for some reason this problem can't be resolved, just what all is involved and how hard would it be to swap to a carbed 305 or 350?? At least then I would cut out all this electrical crap that's impossible to track down because it's beyond me. I just want my bird back.

TomP

I tried to follow all your old messages (kinda hard because there are so many), if I were you I'd find a different mechanic. You want to find one that doesn't need his computer to tell him what's wrong, but can use the computer to "discover" what's wrong.

If you really want to get it fixed, though:

1. There were plenty of suggestions in what I think was your original message at:

https://www.thirdgen.org/forums/v6/5...-firebird.html

I would follow all those suggestions. When RBob mentioned injectors, you asked about upgrades- don't worry about upgrades, just get a junkyard set from any 2.8-3.1 front wheel GM car and put them in. While you're at it, grab a MAP sensor from the junkyard too. The rest of the suggestions are basically saying that all you need is "metered" air (no vacuum leaks, correct vacuum reading from MAP, clean IAC valve/passageway), spark (includes distributor pick up coil, module, and ignition timing), compression, and fuel (correct pressure/volume, filter, injectors, pressure regulator).

2. This is how I've fixed my car for the past 16 years that I've owned it: If the suggestions in that other message don't work, this will: Buy the official GM service manual for your car from http://www.helminc.com . In there are diagnostic charts that start with "engine cranks but wont run". The chart covers EVERYTHING, even the computer. Follow the chart exactly, because at the very end, your car will run and "problem solved"! This is what your Mechanic should be doing.

3. I'm curious as to what your mechanic means by your ECM/computer throwing codes like crazy. What codes is he reading? That statement sounds like an excuse to me- along with the statement that he can't find an ECM! I just found your ECM at Autozone.com for $60- and he can't find one?? (And Pillsbry10 on here has a few ECMs to offer too.) I would also disagree with your mechanic's idea to change out the ECM first and then see what else is wrong, because, if there's a short in a coil that fried your old ECM, it'll fry out your new ECM too. When you change an ECM you have to measure every single input that comes in- and that will be covered in the http://www.helminc.com service manual.

Hope that helps! And you might want to keep all your questions in just one message, it'll help us remember what you did and didn't try. Good luck!

[edit] Oh and switching to carb is just how it sounds- you need to change: engine, exhaust manifolds & y-pipe, carburetor, distributor, fuel pump, transmission, engine mounts, and v8 radiator. You'll also need any parts that connect those to the car. And finally you'll need tools (engine hoist/leveler/stand, etc) and a place to work on it. And you'll also have to check with local emissions/inspection laws to make sure your swap is OK.

jiyasa

iTrader: (1)

Thank you for that address, I'll probably order that. After this one I will try to keep my posts on that original thread you posted. I had over $1,300 in the bank and on a suggestion I bought another (newer) car because I felt at the time my bird needed a break but now I'm down to a few hundred so all these parts I have to be careful where I buy them cause I don't make much (work part time cause I'm a student) and I'm doing this on a budget. Anyways, all I really know about what's going on now is that this place is a small business and they have cars backed out to the road waiting usually and they had mine parked off to the side and I drove by there one night after they were closed, the doors and hood were unlocked which kind of made me uncomfortable but it's not like it's going anywhere. But supposedly to keep the bill down, this young guy in his late 20's works on it after hours when he has time and he's said that he's run a lot of tests and that the computer is throwing codes over things like the IAC sensor, the O2 sensor and so on, things that have been replaced already. So he came to the conclusion that it was the ECM and I'm guessing that the reason he couldn't find one is because he was calling places asking for a "91 firebird ECM" and not the "7730" GM ECM. Basically, lately I've been dropping by there and I tell him what you guys say because you know more things about our fbodies that he doesn't know, so I trust you guys. The plan by the end of this week is to call and find out if the ECM replacement worked or not and then we'll go from there. The only reason I have gone to these guys is because they are willing to work on it on the side to keep the bill down, and with my kind of budget beggars can't be choosers. I've had worse mechanics, if you guys suggest something though I'm more than willing to try.

TomP

Well hopefully it all works out. Gotta say though, on Autozone.com, I didn't ask it for a 7730 ecm. I don't even know what that means (remember that I have a 2.8). I went to the website, clicked on "add a vehicle", told it 91 Firebird 3.1, and typed "computer" into the search box. If you call any parts store and ask for a 91 Firebird 3.1 ECM, they'll look it up as "91 firebird 3.1 ECM" and their computer will give them a part number. Even junkyards have interchange lists (check out car-part.com ); if you call a salvage yard and ask for a 91 Firebird 3.1 ECM, they might give you one from a 1989 Beretta 2.8 that's the same one as your '91 Firebird 3.1- and you'll never know it was from a 1989 Beretta b/c the part numbers are the same.

I still doubt that the guy ever called anyone to look for the computer. If the car is that much trouble for the shop, they won't want to work on it... usually nobody wants a problem car b/c you can't make $$ on it. I just don't want to see you (or the car) getting taken advantage of.

You do have a choice though; to buy the GM manual I mentioned and work through it yourself

[edit] And he cleared the codes before trying to work on it, correct? He's not reading old codes?

jiyasa

iTrader: (1)

He never said whether he cleared them but I think they have just given up. You should just see this place, it's a little ma and pa shop with like three bays with old trucks everywhere, I think they just don't want to admit that it's kind of beyond their capabilities because it's bad for business. So you have a point, they're just guessing and throwing parts at it hoping it will work or that I'll get impatient enough and take it off their hands. So after today if the new ECM doesn't fix it I think I'm going to have it towed back here and just start over because I haven't had it since late may and I miss it. At least I know it will be safe in my own driveway and I can learn how to work on this car. I've been trying to work out of an old chilton's manual and those things are just too generic and vague at times so I may go ahead and get that shop manual you pointed out. Now it has EVERYTHING in it specific to our cars? If I follow the book it will do the job?

Someone told me something and I want your opinion, someone told me that since I obviously can't afford a dealership bill to fix my bird that I could take it to a dealership and have them run a diagnostic test on it and that will give me some idea as to where the problem is coming from and shouldn't cost more than a couple hundred at most. What do you think of that? Can a pontiac dealership do that?

I barely know how to even change my oil so I'm going to start trying to understand mechanics so I'm more than likely going to need help on here. Just don't know where to start learning, can only read so much until you start having to do it.

GTA50

We've all been there. I believe you mentioned that you have another car to drive. With that in mind, I would get the Helms manual that TomP suggested, also buy a metric socket set and some wrenches, a voltmeter and a screwdriver set (including torx). You are now at almost the same stage as your 20 year old mechanic - except you go one better in that you have the Helms manual!!!! LOL.

Seriously, just jump in. If you have a paperclip, you can pull the codes from the ECM and start from there. The book will guide you and at the same time save you a lot of money by avoiding paying for parts you don't need. At the same time you'll learn a lot of great things about these cars.

jiyasa

iTrader: (1)

I really appreciate you guys help, sometimes the way people talk about my car it makes me feel like it's the end for my bird and since 03 it's been my everyday driver so not having it and buying this other car just makes me feel like I've abandoned it and that couldn't be further from the truth, I love my bird. In the last two days suddenly this shop has kicked it into high gear and has been running diagnostics on it so I hope they find something but I really really need to get that book that you guys pointed out. Does this book cover everything? From the way you guys make it sound, it sounds like what I should have done all along.

As of right now, my bird is down and my neon (car I just bought) is overheating.

91phoenix

iTrader: (5)

If the shop doesn't get it fixed then get the GM service manual as suggested. That is a goldmine of information and specific to these cars. I am wanting to find a 91 GM Manual also but am not needing it yet. Yes my V6 isn't running but the people on here are incredible with there knowledge and are willing to share. When you get the car back then if not fixed we can, I am still learning this fuel injection, give you things to check and try to narrow down the problem before buying alot of parts.

jiyasa

iTrader: (1)

I really do appreciate it, at this point I'll take any help I can get. I should be hearing later today about my car from the shop but they "appear" to be taking their time about it saying that they weren't finished last night but are doing more tests and diagnostics today so if it's taking this long I'm hoping they will find something so I can get the ball rolling. But thank you guys for all your help, I'm determined.

TomP

Yes Jiyasa, that book covers everything about your car; that's why it's $105 and over 3 inches thick.

You'll want to go to the diagnostic section and look for the chart "engine cranks but won't run"; do exactly what the chart says, every step, no cheating!! Check off each step as you do it. You may go through 20 pages of charts, but at the end, the car will run again. And yes like GTA50 said, you'll probably need a $5-$10 voltmeter (to check resistance and continuity, the book will say how); look to http://www.harborfreight.com for inexpensive ones (they may have a store near you; type "meter" into their search box, they have one for $1.99).

Little story; in 1996 my car died one next morning about 500 feet from my mechanic! I asked him to take a look at it (it was right down the road after all!), he called me later that day and said the fuel pump wasn't getting any voltage. He said if he jumped it to +12 the car ran fine. He gave me a choice: He could spend hours/days trying to find the electrical problem (at $60 an hour), or, he could hotwire the pump so I could get the car home- and I could track the wiring problem down myself.

I told him I'd diagnose it myself. Once I got home, I pulled out the http://www.helminc.com manual for my 1986 Firebird, ran the chart (engine cranks but won't run- same chart I told you to look at). I had it fixed in under an hour. Turns out it was a bad crimp on the ring terminal on the fuel pump fuse supply wire, at the junction block on the passenger side of the radiator. I cut the old terminal off, crimped a new one on, and it's been good ever since.

jiyasa

iTrader: (1)

Wow, man I would never have another problem getting my car fixed again! I wondered how you guys have kept your cars as long as you have, thank you! How long does it take to get the book shipped and do they accept paypal? Don't think I saw that they did but if not, I have a cc. I really do appreciate your help guys, I have just been beside myself since this happened in may and am so tired of going down the road and seeing my car at night with the doors unlocked and hood popped after the shop closed, I'd rather it be here safe in my carport than at some dark closed up shop. Thank you guys, I'll keep you updated!

Maverick H1L

iTrader: (8)

Look on eBay for a GM service manual. I bought 2 there, both for less combined than what Helm wants for just one. Also, if you do want to get it straight from Helm's, see if you can get all of the additional service publications and updates that went with it. In particular, there was, if it wasn't mentioned in another thread, a TSB (service bulletin) for problems with wiring in the ignition system. I know there are more, but I can't recall them off of the top of my head.

jiyasa

iTrader: (1)

Okay, I'll look into those too. This afternoon was told that after some tests the car is acting as though it doesn't even recognize an ECM, like it's not even there so they are running tests through the electrical system to see what's up. Will keep everyone posted, thanks everyone!

TomP

LOL, the manual that Maverick's talking about is the same one I am; GM service manual = published by http://www.helminc.com . If you buy a used one from an auction website make sure all the pages are there, seller is reputable, etc- much easier just to tell you to buy it new from helminc.com

Dude that's a weird diagnostic the shop just gave you. A few days ago the ECM was throwing codes, now it's not there anymore? DId they forget to reconnect it? What electrical tests are they running anyway (I'd ask them- and "checking things with a meter" isn't a good answer- checking WHICH things?)

GTA50

With the ECM is connected, to get the codes, you just have to jumper the A-B terminals (the two at the top right) in the ALDL. This is the diagnostic port under the dash - just below and to the right of the steering wheel. Turn the ignition to "on". There should be a flash of "1" then "2" for code 12 to tell you that the system is functioning properly. This flashes 3 times then on to the next code. All codes are two digit.

Anyway, with the list of codes, members here can certainly help you to get your car running. Also, there are checks for you ECM before you just replace it. Remember that voltmeter?

jiyasa

iTrader: (1)

Yeah, it's kind of weird, I wonder if they even know about the paperclip trick. I don't know, might sneak over there tonight after the shop has closed up and if its outside I'll try it for myself and see if it's working. I don't know what's going on now, it's starting to make me nervous.

As far as the book, I think what I'm going to do this next week is order it new from that website. I think $105 is more than worth it in the long run. But yeah, I have a voltmeter. Don't know how to use it very well or what I'm using it on but I do have one.

jiyasa

iTrader: (1)

Is this what your's looks like? I'm still more inclined to go the new route from helms but just for my own curiousity...

http://cgi.ebay.com/ebaymotors/1991-...sQ5fLiterature

GTA50

The covers change from year to year, but yeah, that does look similar as to the contents. I have manuals for each of my Firebirds and every year is slightly different. For my '94, there are two volumes!!!!!

jiyasa

iTrader: (1)

The shop called me yesterday and told me they have found out the problem. They said that the number 5 injector had an internal short in it and blew, so this was causing the code 33. They said they pulled the bad injector and the car fired right up and ran. I don't know about the earlier firebirds but I have two keys, one for the doors/t-tops and one with the little transistor in the ignition key. The car wasn't recognizing the ECM because of the security system, it needed the code and as soon as the shop found this code it acknowledged the ECM and worked normally.

As of right now, they are looking for a new injector. Since someone else on here pointed out to me in my original thread that I should not even check the injectors, just replace them I'm looking into sets of 6 for my year of bird and I was wondering if you guys could point me in the direction of where I could find a reliable site/place that I can find a set for a decent price?? Decided that I want to go new and not used, at least that way I have a warranty. Do you think I should just replace the one or go ahead and replace all six? I don't understand the difference in lbs. (seen them from 16 up to 24 lbs., multiport, TPi, etc.) What type/lbs. do I need for a 3.1L?? These things are expensive!!!

TomP

Yes you found the same manual, here's how to tell- look at the picture on the auction website, zoom in, in the lower left corner it says S-9110-F. Now go onto http://www.helminc.com and look up your car (vehicle owner, pontiac, service/owner info, 91 Firebird) and see the stock number for the book is "(English, Paper, S9110F)"

Good to hear the shop IS making some progress! As for the injectors, read my first message way up top... oh well I'll just requote it here:

A junkyard set shouldn't cost more than $50. That way your car comes back to you running OK and you can spend the time/energy/$$ later to do an upgrade. I don't think at this point you'd even see a performance benefit from higher flowing "upgraded" injectors... guys have to do a bunch of mods first to see gains.

But either way it's cool that the shop did come thru for you!

GTA50

For injectors, I would try Southbay Injectors.

I bought a set for my '88 GTA and the price was $130 for the full set!! They've been overhauled and tested so I would go that route versus the JK just to make sure that you have a good set and don't have to go through this aggravation again.

jiyasa

iTrader: (1)

To draw this to a close, I picked up the car wednesday morning and despite all the waiting and frustration they only charged me $200 so can't complain there. Before I got a chance to ask them to swap out all six injectors and replace them all they already went ahead and just bought the one and fixed the problem injector and it does run fine. After all I've been through though, I'm at that point where I'm almost trying to anticipate the next problem so I can fix it. Thank you for all your help guys, I really do appreciate it!

BTW, nothing serious but just annoying, a couple years ago I had the front end rebuilt and (pardon my lack of mechanical vocab) inside the engine compartment where the struts bolt into (has little rubber cones that snap over them) they kept clunking around and I kept hearing rattling and I was told this is what I need to replace to get rid of that noise. Kept taking the cones off and spraying white lithium grease in there as a band-aid fix but I just want to go ahead and replace them. Do you guys know what I'm talking about and where I might find these at?

TomP

Glad they got it fixed for you! Make sure you get that GM service manual so you'll be prepared next time. In fact you should go through some of the diagnostic charts anyway (while the car is running good), can check things like sensors & vacuum lines & etc. Doesn't hurt!

Those suspension parts are called the strut mounts (or "upper" strut mounts), they bolt to the strut towers. You can't just remove them and bolt new ones in- you'll need to trace around them in paint first because their location affects your alignment. The bolt holes are elongated to allow for adjustment (which is what tire shops would do). You'd install the new ones in the same positions, then you have to go for an alignment.

Luckily you're a '91 car. They changed the bolt pattern in '87- but they only sell 87-up strut mounts! So guys like me (with an '86) need to get the brackets (underneath the strut tower- right above the tire) from an '87-up junkyard car. But you don't have to worry about that with your '91, they'll bolt right in, summitracing.com has 'em, local store should too. Replacement is covered in both the GM Service Manual (helminc.com) and the Haynes 82-92 book too.

And yes the bearing in the strut mounts wears out over time. If that was a few years ago you might want to replace the struts too.

Maverick H1L

iTrader: (8)

And the strut mounts are $60 a pop... Going to replace mine as well (rust delete , and the fact that if the rest of the rubber bushings in the suspension are shot, those probably are as well ). I agree with replacing the struts. Also the rear shocks if you can't find out when they were last replaced.