TBIThrottle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.
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Hi everyone, I'm having some issues with my car lately and I was hoping I could pick everyone's brain on here. I tried searching with some key words but it just didn't seem to pull up any posts with somebody with the same issue. Any help would be soooo much appreciated, thank you. Here's the back story and what's going on now... I will put as much info about the car as I can because I don't know what is or is not relevant to the issue.
The car is an '88 Formula TBI 305 auto. It's got high milage, like 180K+ but I'm not sure. Lately it has been brutally cold here in Kansas City. This car has become my daily driver as of July '07 because I bought an '02 Firehawk that just has too much HP to handle driving in bad slick conditions. In the past month or so I have seen a dramatic loss of power in my '88. When I'm driving it takes FOREVER to accelerate up to speed, I know everybody around me is like 'c'mon that car is faster than that....' LOL. It makes this 'pop' sound and sounds like it's going to die several times in the 10 miles I drive on the highway to get to work. The popping is coming from under the hood somewhere. I also notice this clicking sound all the time coming from right in front of me while I'm driving. I held my head closer to it while it was running and it's coming from the driver's side of the motor. I was told by someone that it is just the exhaust, and that made sense at the time because I never noticed it until I put headers on it. It just doesn't seem right to me. It is getting TERRIBLE gas mileage, like 11mpg. In case the super cold air is a factor, it does have an aftermarket ram air hood on it so it's sucking 10 degree air in like a monster.
Please help me! I love this car, and I am really hoping I have not put it through too much lately driving it everyday.
obvious issue with the engine...have you done any tune of up any sort...spark plugs, wires, cap? Otherwise your going to have to have someone help identify if you have a knock in your engine and have them explain how to check compression of the motor...it may be on it's way out, but don't get your head down just yet! Let someone work with you on those two things i mentioned, and including anything that you have done to the car, last time you worked on it, last time you changed anything to do with the engine, and any codes the car may have if you have resources to get the codes out of the car (if the engine is even throwing any codes).
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
one more thing..... almost forgot that the check engine light comes on sometimes when I'm driving but it goes off next time I start the car again. seems like it's never on when i am somewhere that i can check the code and i don't know if it's related or not.
thank you
Emily
and thank you for your response 84redta. i was afraid i was going to find out it was a motor problem... vbmenu_register("postmenu_3655188", true);
Last edited by whitehawk02; 02-26-2008 at 10:54 AM.
Like 84redta said, if you dont know when anything that he said has been changed, now would be a great time to do it, plugs, wires, cap, rotor, and fuel filter. These are all very inexpensive fixes if they are the problem, and if you car seems to be "poping" it almost sound like your running too lean and back firing, or your timing is off, and that would be another thing to check or have someone check, and with the slow acceleration almost makes it sound like a really lean or off timing situation. And if you can tell the difference between a "pop" and a "knock" thats good cause most of the time a "pop" is cheaper than a "knock" to fix (dont hold me to it though) But a good place to start is with the basic replacement parts and go from there.
if you can get the car to make that knock/pop while the car is parked in your driveway, you can take the top of the air cleaner off...if it gets louder i'm leaning toward popping (lean), and if it stays the same i would lean towards a knock (couple more problems).
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
Yeah, I know the plugs and wires were changed when the headers were put on about 7 months ago. Since I have owned the car no new cap, rotor, or fuel filter.
I also was wondering about the car running lean possibley, because the 'pop' I mentioned is like a backfire type sound. And, I have adjusted the timing several times - it seems to run better for a week or two, and then the timing is off again. Another thing is, the motor is a NAPA rebuild that has about 16,000 miles on it based on the receipts I have. The actual TBI unit itself is as old and high-miled as the car, and I have no idea if the injectors have ever been changed or anything.
LOL, the 'pop' is cheaper to fix than the 'knock'.... I like that. Yes, the only sound that could be compared to a knock, is that tick tick tick sound I hear and was told that it may be due to putting headers on it. What do you guys think of that suggestion?
You all are such a great resource! Thanks so much!!!!
either way, take the air cleaner off of the car (big round lid atop the engine around the air filter). Take a look in there your going to see your TBI with two bores going into the top of the engine and you'll see your fuel injectors sitting there squirting fuel in there. How does the fuel look, they are supposed to be cone shaped squirts. If you see it drizling or anything like that, then i would lean towards you having a fuel issue.
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
if you can get the car to make that knock/pop while the car is parked in your driveway, you can take the top of the air cleaner off...if it gets louder i'm leaning toward popping (lean), and if it stays the same i would lean towards a knock (couple more problems).
I can get it to make to pop sound in the driveway when I give it some gas. I will check that out. The other sound.... I'm not so sure about.
I do know about 3 months ago it was doing this backfire-pop thing and it was the coil grounding out on the bottom part of the air cleaner. Maybe we should dig around for something weird like that again.
i've heard headers doing that ticking, but have yet to put headers on my car so i can't really say from experience.
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dig around for the obvious things, make sure that the plugs are all wired securely, in the right firing order, simple things like that, if your fuel filter underneath the driver side of the car is getting rusty and you have no recolection of replacing it , it's probably a good time to do that, make sure the fuel lines all look good and if they are rusty make sure there are no holes or leaks, inside the TBI, is it all clean or gunked up? Have you tried running fuel injector cleaner thru a tank of gas before going out and paying $70-$80 an injector. Just a couple more simple cheap things to think about to address the "pop." As mentioned the click may be normal, someone else is going to have to vouch for that.
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also what are the miles on the TBI, as you said it's as old as the car. I just got a "rebuild" kit for my TBI, only $30 and everything is new.
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
Last edited by 84redta; 02-26-2008 at 11:27 AM.
Reason: Automerged Doublepost
No, I have not tried to run injector cleaner through it yet. I will pick some up on my way home today. Can I get one of those TBI rebuild kits at the auto parts store?
Another thing that may or may not be applicable to the power loss is that I noticed while I was on the highway today and doing my turtle speed acceleration that no matter how much I pushed down on the gas pedal the RPM's would absolutely not go above about 1700-1800. Like I was cruising at about 60mph when I finally got that fast, and that's the RPM it was running and if I gave it some gas the RPM gauge did not budge above that point at all. This was all while the engine light was on also, but unsure what code it was sending.
i did...hop into the TBI forum, and maybe less than 10 down on the list is a title "TB Rebuild Kit." In there you will find i have posted a part number i got from advanced auto, but napa has them as well should any parts store.
You should be able to get a code reader from the parts store, i think something like $25-$50 for the GM specific ones, but i would suggest to spend you money wisely and get a really good one, because the really good ones will have a screen and give you a code number and potential problem, where as the code reader you would buy will just flash a number for you. Ultimately if your worried about saving money so far, i would suggest you invest in a paper clip. You can get the codes off your car by connecting two terminals on your ALDL connecter underneath the dash, and your service engine light will actually flash the code that has tripped on your car. If you were to do that, and bring us back the code, we would be able to help you more appropriately as that will pinpoint the system of issue. Honestly i would ask the person at your parts store for help, play dumb, and see if they have a machine they can plug in to at least give you the engine code that it's reading.
Your RPMs aren't going to go up if the engine doesn't have the willpower and energy to make it go up.
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i mean really this could be as simple as a bad O2 sensor making your engine run lean, so thats why i say before you drop money in (i would suggest you do a tune up of the simple and cheap things anyways for good maintanance), you figure out the code and we can point you in the right direction, but at least you could fix your problem now, and then do the maintenance your car probably needs.
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
Last edited by 84redta; 02-26-2008 at 12:03 PM.
Reason: Automerged Doublepost
Ultimately if your worried about saving money so far, i would suggest you invest in a paper clip. You can get the codes off your car by connecting two terminals on your ALDL connecter underneath the dash, and your service engine light will actually flash the code that has tripped on your car. If you were to do that, and bring us back the code, we would be able to help you more appropriately as that will pinpoint the system of issue. Honestly i would ask the person at your parts store for help, play dumb, and see if they have a machine they can plug in to at least give you the engine code that it's reading.
Your RPMs aren't going to go up if the engine doesn't have the willpower and energy to make it go up.
About the RPM's... that's kinda what I was thinking too. Glad you could confirm it. And I will check that code like you said. I have used the paper clip method before. I always thought it was cool that you could do that. I will let you know what code it's throwing and we will go from there.
sounds like a plan. Yea before the paper clip idea i was mad paying $50+ for sum b.s. "diagnostic fee." I still went out and spend $150 on ebay or a code reader that reads older domestic cars (80s-95 ford, GM, chrysler), and all newer OBD II systems (96+ cars) so that i can have a more accurate reading and also work on newer cars. The investment will pay for itself, often times the very first couple of times you would have to had to take it to a dealer.
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by the way, you got any pics you can attatch of the car, that car looks really nice, is that the sunset orange paint and a fourth gen wrap around???
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
Last edited by 84redta; 02-26-2008 at 12:09 PM.
Reason: Automerged Doublepost
THANKS! Yeah, I will post some pics as soon as I can. Sunset Orange, yes. And it is the 4th gen spoiler. Has the ram air hood as well, and some bad *** (if I do say so myself) 4th gen Camaro seats recovered in whilte leather.
Like I said, this car has become my daily driver unintentionally. It is not a car that I abuse and I am fearful that I have put it under too much stress lately.
Last edited by whitehawk02; 02-26-2008 at 01:22 PM.
Just a thought to keep in mind, and i doubt that this would be the problem, but just because you said that the engine was a rebuild from napa, is that there could be a slight chance that your timing chain skipped a couple teeth on the gear, and would make it so that now matter how much you turned the distributor you wouldnt be able to get the timing right. Also it just occured to me, check under the dash where you would put you feet if you were the passenger and just make sure you computer connections are good, and that the wire plugs didnt come off or partially off. This could throw off the whole system and make your car run like crap.
here's some pictures that you asked for. one of them is during the painting process, and there's one of the seats also. I have more but it would only let me attach the three.
THANKS!!! Actually I'm trying really hard to locate the another front bumper like the original, the one with the two black things in the front, you know??? I really thought I would love the looks of the one that's on there now, but I'm not so sure the car lines up right and I'm discovering that it really needs the ground effects to look good. Also, I think - being after market and all - that the hood needs the original parts on the car to line up right as well.
Soooooo, if anybody knows of a front bumper from a Formula that year or close that has the two black inserts on it..... let me know
I can get you the honey comb underneath, bumper, and the headlights so that they will fit the "headlight" bucket of the older bumpers. PM me if your interested in something like this.
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
For the bumper, you really should look for a 91-92 *Formula* bumper. It doesent need the GFX to look good. And they should all line up the same. It would look best on your car, especially with that hood. Also, look for a 91-92 formula rear bumper.
For the RPM's not changing, it kinda sounds like the torque convertor is not un-locking. Was the tranny ever replaced or rebuilt, or is that still high milage?
You really need to get that code pulled. Remember, even if the light comes on, then goes off really quick, you can still pull the code. It stays in memory for a while , 2 months I think, but dont quote me. So anytime you can get the paperclip in there, the code(s) will still be waiting.
I believe for automatic cars, there should be another two pins you can jump on the ALDL, while driving, and it will lock up the TC completely. You could try that to see if that simulates the problem.
__________________ -Adam
1990 Firebird Formula
Bone Stock 305TBI, T5 tranny, 62k Origional
UMI subframe Connectors
For the bumper, you really should look for a 91-92 *Formula* bumper. It doesent need the GFX to look good. And they should all line up the same. It would look best on your car, especially with that hood. Also, look for a 91-92 formula rear bumper.
For the RPM's not changing, it kinda sounds like the torque convertor is not un-locking. Was the tranny ever replaced or rebuilt, or is that still high milage?
You really need to get that code pulled. Remember, even if the light comes on, then goes off really quick, you can still pull the code. It stays in memory for a while , 2 months I think, but dont quote me. So anytime you can get the paperclip in there, the code(s) will still be waiting.
I believe for automatic cars, there should be another two pins you can jump on the ALDL, while driving, and it will lock up the TC completely. You could try that to see if that simulates the problem.
Thank you, I will check the code as soon as I get home from work today.
Love your car BTW! Looks like mine used to except cleaner with that low mileage, same color and all.
And your mention of the torque converter... I hadn't thought of that. Good call. It is a replacement 700r4 out of a '90 camaro that I believe had around 130K, mine was shot so I had to replace it. So, yes, the mileage is high.
And about the bumper; I'm not sure I've seen the one you are talking about I will have to find a picture of one. I know my friends' '89 looks real good with the bumper I want to find again for my car and the ram air hood. (I'll attach a pic)
Well, the car ran MUCH better this morning! All the talk of the fuel being lean and everything appears to have been right on. I checked the spray from the injectors and it looked good. What I finally decided to do was close up the vents on the ram air hood so the car could mix fuel/air easier. I think the rush of all that freezing cold air was just too much for it to handle. I'll open them back up once spring gets here, car does better then. Let the air come in like it was meant to in the mean time.
I also adjusted the timing with a light this time instead of by ear. That seems to have helped.... hmmm imagine that.
I still have that funning ticking sound, but I'm putting that off until spring too unless it gets worse, still could just be the exhaust.
for the ticking noise, if you think its the headers, you might try tightening the header bolts. once headers have been put and you let the metal go through a few heat cycles, they become a little easier to tighten. i had a ticking noise like that from my 86. finally realized it was the headers. tightening them down helped a little bit but i had cheap *** headers on the car so it still made the noise.
for the ticking noise, if you think its the headers, you might try tightening the header bolts. once headers have been put and you let the metal go through a few heat cycles, they become a little easier to tighten. i had a ticking noise like that from my 86. finally realized it was the headers. tightening them down helped a little bit but i had cheap *** headers on the car so it still made the noise.
I will check that out. I know they have not been tightened since they were installed and I would imagine there is some shifting and such that goes on while driving so they can get more into place. These are not cheap headers at all so hopefully if that's where the noise is from it will stop with some tightening. Thanks for the input 86firebird350.
Sounds like you have almost solved your problem but there was one thing I did not see in any of the posts that could also explain your loo of power - a plugged or partially plugged catalytic converter. If you are still scratching your head (and especially if you have a dual exhaust set up) it might provide another reason for your engine's lack of power.
my thought was the fact that with the ram air, the brutally cold air, maybe the air/fuel ratio was getting screwed with (if hooked up to the TBI directly), it wasn't bumping fuel for additional air. Just a couple thoughts that played in my head.
__________________ 1988 Bare t-topped Firebird L03/ WC T5/ Open drum 3.08 - - > Gunmetal LT1/T56 powered GTA with LS1 4:10 rear disks to boot.
83 Daytona 500 Trans Am pace car, 1 of 2500 built, will be revived...pics coming soon!
92 Heritage RS Camaro, one of ~8200 in counting, will hopefully be running in time for NYThirdGen 4th of July car cruise on Deer Park Ave, LI.
Definately check the header bolts for that ticking, at the track every saturday night, i check the header bolts on our racecar after every time the car is out on the track, (hot laps, heat race, feature) and you would be suprised how some of those bolts loosen up on you.
Sounds like you have almost solved your problem but there was one thing I did not see in any of the posts that could also explain your loo of power - a plugged or partially plugged catalytic converter. If you are still scratching your head (and especially if you have a dual exhaust set up) it might provide another reason for your engine's lack of power.
No cat. Took it out when we put the headers and new exhaust on the car.
As for the headers, yeah you should try tightening them. People say, after installing headers, you should tighten them every day for the first week they are on. One time is not enough.
For the hood, that kinda makes sense. On wet induction motors (i.e. TBI and carb) the engine relies on the heat of the intake manifold to "evaporate" the fuel into vapor form from liquid. That is the whole reason for the Thermac system for cold starting. I am guessing that the intake charge you were getting was so cold, that the fuel was getting into the cylinders still liquid, and not completely combusting.
As for the bumpers, this is the formula nose without the GFX:
this is the rear bumper:
__________________ -Adam
1990 Firebird Formula
Bone Stock 305TBI, T5 tranny, 62k Origional
UMI subframe Connectors
One thing you could do if to get the most out of your hood function, is start some chip tuning and datalogging with an ALDL cable and a laptop. And make a chip that would let your car run the right way in the winter and another chip to make it run the right way in the summer, just a thought
xjcamaro98: I will check in to that for sure, it would be nice to get the most out of this hood!
slow_90firebird: Thanks for the pictures. Yeah, that front bumper looks a heck of a lot better than the one that I've got on there right now seeing as I don't have the Trans Am GFX. I will try to find one. The one on there now came off of a '91 GTA Trans Am.... that leads me to something kinda off topic, and I imagine I could find out from somewhere else; is there a such thing as a Formula GTA? Dumb question probably, but I've only seen Trans Ams.
Last edited by whitehawk02; 02-27-2008 at 03:22 PM.
Reason: clarification
Yeah, formulas were kind like base model cars. They traded the creature comforts and fancy GFX for aerodynamics and weight reduction. They only had what was necessary for performance, like the WS6 suspension, and V8 powerplant.
That said, whoever bought my car was completely stupid. They ordered the formula package, but added all kinds of power acc. like windows, door locks, elec. mirrors, cruise control, rear hatch release, and rear defrost. They bought the T-top option too. Then, they skimp on the powerplant by getting the LO3. They couldnt even buy the Lb9 motor which would have been nice. Finally, to top it off, they got the T5, which involves more work to shift, then they saved by paying for all the power accs.
__________________ -Adam
1990 Firebird Formula
Bone Stock 305TBI, T5 tranny, 62k Origional
UMI subframe Connectors
So normally my car being the WS6 Formula would not have had power accessories, like power windows and stuff? It has the power windows, locks, hatch, and cruise control. No T-tops, rear defrost, or side mirrors though.
Well, i am not so sure on the exact stuff that could / couldnt be had. You could check the history restoration forum for better info.
What I was basically getting at, was that the whole idea behind the formula, was a car that was supposed to be all go, no show. Sure, you could custom order the car with all the power accs that I have in mine, but whats the point? If they wanted to be comfortable and save money, they could have gotten the base model firebird, with power accessories. If they wanted to have the show, they could have ordered the bottom end T/A.
__________________ -Adam
1990 Firebird Formula
Bone Stock 305TBI, T5 tranny, 62k Origional
UMI subframe Connectors