Throttle body question
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 30
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From: Iowa
Throttle body question
So i have recently bought my first vette it's a 1987 coupe with the l98. When i bought the car it came with a bbk 58mm tb already installed but i don't feel like it doing much good since the engine is bone stock minus the off brand ebay "upgrade" fuel injectors. My question is should i go back to a stock 48mm tb or what other tbs are out there to make them run good all the way around cause i trying to get the vette running right again. The car does run and drive fine but only on the highway above 55 mph is where is feels comfortable to drive at and most fun. Any inputs would be nice i have not work with tpi engine intill this one.
Team Owner
Joined: Jul 2004
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From: Hartford WI
So i have recently bought my first vette it's a 1987 coupe with the l98. When i bought the car it came with a bbk 58mm tb already installed but i don't feel like it doing much good since the engine is bone stock
minus the off brand ebay "upgrade" fuel injectors.
My question is should i go back to a stock 48mm tb or what other tbs are out there to make them run good all the way around cause i trying to get the vette running right again.
The car does run and drive fine but only on the highway above 55 mph is where is feels comfortable to drive at and most fun. Any inputs would be nice i have not work with tpi engine intill this one.
minus the off brand ebay "upgrade" fuel injectors.
My question is should i go back to a stock 48mm tb or what other tbs are out there to make them run good all the way around cause i trying to get the vette running right again.
The car does run and drive fine but only on the highway above 55 mph is where is feels comfortable to drive at and most fun. Any inputs would be nice i have not work with tpi engine intill this one.
Problem with the upgrade fuel injectors is that we don't know the size. What the PO, aka liar, aka idiot seems to think is that if we get more air and more fuel, it makes power. While it is true, it works AS A SYSTEM and not a random bunch of parts. You need to check if they are the right sized ones or the ECM will compensate as much as it can and cause problems.
Define "running right"? What is it doing right now? I have strong doubts it is the TB. If I had to guess, I'd go with wrong sized injectors until proven that they are right.
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 30
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From: Iowa
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Difficult to know what you mean by running right. A 58mm does not hurt you, but its not really helping you either. Getting it to idle correctly and some throttle response can be its main issues, which aren't big issues.
You can find a stock one in a junkyard, that is probably your best bet. A 52mm is also going to be fine and is generally what we would let people change if we're talking about waking an L98 up, but again is not needed for a stock car.
The injectors I'd take out and have tested, if they are aftermarket there is not much I can tell you about them if you don't have a receipt. You should have 22lb/hr injectors in 87, if FIC can tell you what they are, even better. Otherwise, replace with new Bosch at the same fuel rating.
An investment worth making is to buy an Actron Scanner from Advance/Autozone that can read OBD-I data from the ECM. Not just codes, data. That will tell us something we can go on and see if its not running correctly.
You can find a stock one in a junkyard, that is probably your best bet. A 52mm is also going to be fine and is generally what we would let people change if we're talking about waking an L98 up, but again is not needed for a stock car.
The injectors I'd take out and have tested, if they are aftermarket there is not much I can tell you about them if you don't have a receipt. You should have 22lb/hr injectors in 87, if FIC can tell you what they are, even better. Otherwise, replace with new Bosch at the same fuel rating.
An investment worth making is to buy an Actron Scanner from Advance/Autozone that can read OBD-I data from the ECM. Not just codes, data. That will tell us something we can go on and see if its not running correctly.
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 30
Likes: 0
From: Iowa
First off, even if it does any good, how will you know without a dyno or running it on a track? Second, it really doesn't since all you are doing is expanding the amount of air available via the TB and you still need to get the intake to bring it to the cylinders. Third, it really won't do much till you open up the heads and change the rest of the engine. So short answer, NO. I had a friend try that with 3 sets of runs. With and without. Consistently went slower with the TB but he swore it made it feel faster until he took the challenge and tried it on the track.
Problem with the upgrade fuel injectors is that we don't know the size. What the PO, aka liar, aka idiot seems to think is that if we get more air and more fuel, it makes power. While it is true, it works AS A SYSTEM and not a random bunch of parts. You need to check if they are the right sized ones or the ECM will compensate as much as it can and cause problems.
Define "running right"? What is it doing right now? I have strong doubts it is the TB. If I had to guess, I'd go with wrong sized injectors until proven that they are right.
Problem with the upgrade fuel injectors is that we don't know the size. What the PO, aka liar, aka idiot seems to think is that if we get more air and more fuel, it makes power. While it is true, it works AS A SYSTEM and not a random bunch of parts. You need to check if they are the right sized ones or the ECM will compensate as much as it can and cause problems.
Define "running right"? What is it doing right now? I have strong doubts it is the TB. If I had to guess, I'd go with wrong sized injectors until proven that they are right.
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 30
Likes: 0
From: Iowa
Difficult to know what you mean by running right. A 58mm does not hurt you, but its not really helping you either. Getting it to idle correctly and some throttle response can be its main issues, which aren't big issues.
You can find a stock one in a junkyard, that is probably your best bet. A 52mm is also going to be fine and is generally what we would let people change if we're talking about waking an L98 up, but again is not needed for a stock car.
The injectors I'd take out and have tested, if they are aftermarket there is not much I can tell you about them if you don't have a receipt. You should have 22lb/hr injectors in 87, if FIC can tell you what they are, even better. Otherwise, replace with new Bosch at the same fuel rating.
An investment worth making is to buy an Actron Scanner from Advance/Autozone that can read OBD-I data from the ECM. Not just codes, data. That will tell us something we can go on and see if its not running correctly.
You can find a stock one in a junkyard, that is probably your best bet. A 52mm is also going to be fine and is generally what we would let people change if we're talking about waking an L98 up, but again is not needed for a stock car.
The injectors I'd take out and have tested, if they are aftermarket there is not much I can tell you about them if you don't have a receipt. You should have 22lb/hr injectors in 87, if FIC can tell you what they are, even better. Otherwise, replace with new Bosch at the same fuel rating.
An investment worth making is to buy an Actron Scanner from Advance/Autozone that can read OBD-I data from the ECM. Not just codes, data. That will tell us something we can go on and see if its not running correctly.
Last edited by Patrick Spitler; Mar 7, 2018 at 01:34 PM.
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Thread Starter
Intermediate
Joined: Feb 2018
Posts: 30
Likes: 0
From: Iowa
Alright after going to take a better look at the injectors i found a name on them and track them to osidetiger fuel injectors there rated at 21/lbs@43.5 psi flow balanced 4 hole injectors there re-manufactured Genuine Bosch from what the product info on ebay says.
Safety Car
Joined: Sep 2001
Posts: 4,154
Likes: 553
From: Glenbeulah Wi
So i have recently bought my first vette it's a 1987 coupe with the l98. When i bought the car it came with a bbk 58mm tb already installed but i don't feel like it doing much good since the engine is bone stock minus the off brand ebay "upgrade" fuel injectors. My question is should i go back to a stock 48mm tb or what other tbs are out there to make them run good all the way around cause i trying to get the vette running right again. The car does run and drive fine but only on the highway above 55 mph is where is feels comfortable to drive at and most fun. Any inputs would be nice i have not work with tpi engine intill this one.
As far as running correctly you need to find what the other issues are that are causing the car to run poorly.
Team Owner
Joined: Sep 2001
Posts: 62,141
Likes: 1,729
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
You need to log some data and really try to figure out what else might be going on with the car.
Last edited by vader86; Mar 7, 2018 at 05:05 PM.
Team Owner
Joined: Jul 2004
Posts: 28,426
Likes: 3,277
From: Hartford WI
The injectors I'd take out and have tested, if they are aftermarket there is not much I can tell you about them if you don't have a receipt. You should have 22lb/hr injectors in 87, if FIC can tell you what they are, even better. Otherwise, replace with new Bosch at the same fuel rating.
An investment worth making is to buy an Actron Scanner from Advance/Autozone that can read OBD-I data from the ECM. Not just codes, data. That will tell us something we can go on and see if its not running correctly.
An investment worth making is to buy an Actron Scanner from Advance/Autozone that can read OBD-I data from the ECM. Not just codes, data. That will tell us something we can go on and see if its not running correctly.
No they do not work Tried recently on my 91 and called tech support. They don't support something that old. Probably should get aldldroid or SnapOn.
Drifting
Joined: Jul 2015
Posts: 1,270
Likes: 239
From: Sun City West, AZ
Leave the Throttle Body alone and save the money. If you're having a problem with it running rough, I would look at other stuff like wires, Mass Air Flow, Injectors, plugs, etc. The injectors don't like crap gas and if crap gas was used the injectors will get out of balance.
I would start using Chevron gasoline and if you don't have Chevron stations in your area start using Techron. Your injectors will love you if they're not too far gone.
I would start using Chevron gasoline and if you don't have Chevron stations in your area start using Techron. Your injectors will love you if they're not too far gone.
Team Owner
Joined: Jul 2004
Posts: 28,426
Likes: 3,277
From: Hartford WI
The guy i bought the vette from throw some performance parts at it trying to get running again and the problem was the ecm he replaced it and it started up and drove again. As for the injectors no clue what they or the size of them but i do plan on getting new injectors and a reprogrammed ecm chip for it and have the chip set to the new injectors flow rate. As for what i mean about not running right the car just when i am driving it around town i notice it hesitate's when i hit the gas pedal then it will react with in a few seconds and run right. I don't have the problem on the highway it very nice there but in town it just don't feel right i have adjusted the throttle linkage to soften it up a bit cause when i got the car it was rock hard trying to get into the gas and when i did i found myself doing burnout's. the guy i bought it from had no clue on what he was doing but i give him a for effort but i have to go back and redo what he did to see whats going on. But i was hoping someone on this forum has ran or is running this tb and go from there,
Team Owner
Joined: Jul 2004
Posts: 28,426
Likes: 3,277
From: Hartford WI
Leave the Throttle Body alone and save the money. If you're having a problem with it running rough, I would look at other stuff like wires, Mass Air Flow, Injectors, plugs, etc. The injectors don't like crap gas and if crap gas was used the injectors will get out of balance.
I would start using Chevron gasoline and if you don't have Chevron stations in your area start using Techron. Your injectors will love you if they're not too far gone.
I would start using Chevron gasoline and if you don't have Chevron stations in your area start using Techron. Your injectors will love you if they're not too far gone.
Drifting
Joined: Jul 2015
Posts: 1,270
Likes: 239
From: Sun City West, AZ
If there are no Chevron stations in your area, a bottle of Techron every so often will help.
Team Owner
Joined: Jul 2004
Posts: 28,426
Likes: 3,277
From: Hartford WI
The Techron is pretty damn good snake oil and actually does work providing that the injectors are not too far gone. It wouldn't hurt to try it in a tank of gas.
The Techron will definitely help keep the new injectors from clogging up.
If there are no Chevron stations in your area, a bottle of Techron every so often will help.
The Techron will definitely help keep the new injectors from clogging up.
If there are no Chevron stations in your area, a bottle of Techron every so often will help.
I'm sure you believe it will. I take it that you have seen the laboratory results or is it only the SOTP dyno aka placebo effect?
How is it better than any of the other top tier ones? More or better detergent? Higher than advertised octane? Assuming that the detergent really works that is.
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 30
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From: Iowa
There is no need to get Accel injectors or do anything to the chip, that will not help it. Off the shelf chips are worthless and you have no modifications that require a custom one. If these are 21.5 lb/hr at 43.5psi you are probably fine here.
You need to log some data and really try to figure out what else might be going on with the car.
You need to log some data and really try to figure out what else might be going on with the car.
Last edited by Patrick Spitler; Mar 7, 2018 at 07:34 PM.
Drifting
Joined: Jul 2015
Posts: 1,270
Likes: 239
From: Sun City West, AZ
I'm sure it is 100% success at separating people from their money. If the injectors are shot, nothing but replacement will help. I don't know if Multec like the stuff around the coil as much as ethanol which eats the coil winding insulation.
I'm sure you believe it will. I take it that you have seen the laboratory results or is it only the SOTP dyno aka placebo effect?
How is it better than any of the other top tier ones? More or better detergent? Higher than advertised octane? Assuming that the detergent really works that is.
I'm sure you believe it will. I take it that you have seen the laboratory results or is it only the SOTP dyno aka placebo effect?
How is it better than any of the other top tier ones? More or better detergent? Higher than advertised octane? Assuming that the detergent really works that is.
Team Owner
Joined: Jul 2004
Posts: 28,426
Likes: 3,277
From: Hartford WI
I understand that. I also can read what the members only top tier group say. Beyond that, I am not entirely certain that "some additive is good, more is better". I'd definitely like to see some efficacy testing to justify the cost. I don't have the money or the motivation (since I am not selling anything) to pay for a test so the best I have been able to do is to test the flow before and after cleaning and compare my results to what FIC or other cleaning companies send back. In a LIMITED fashion, I know that they are not giving me BS about how good a job they are doing. I know what they are getting and know what they are returning.