Injector Questions and Hard Start?
#1
Injector Questions and Hard Start?
I have a 88 350 TPI with around 130K miles on it. It has a new fuel pump and seems to run fine except for starting hard when warm. If the car sits overnight or a few days it starts just fine but after I take it for a drive it seems like its flooding and takes a while before it fires back up. Would new injectors help this? I'm new to the car / TPI systems and not sure if these have ever been replaced or need to be. The car was barely started for quite a few years. I'm just trying to make it a drivable and reliable car and not sure what I should look at as far as doing a complete tune up, etc. Thanks for any help.
#2
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Car: 1988 Trans Am GTA
Engine: 5.7 L98
Transmission: 700r4
Axle/Gears: Borg Warner 9 bolt 3.27
Re: Injector Questions and Hard Start?
Sounds like the injectors are done, the symptoms are all there from what you mentioned and my car did the same and once I replaced the injectors it was good to go.
If you do the injectors replace the Fuel pressure regulator diaphragm while in there.
If you do the injectors replace the Fuel pressure regulator diaphragm while in there.
#3
Re: Injector Questions and Hard Start?
Thanks so much for your help. Do you have a source for the injectors and fuel regulator diaphragm? It's just a stock 88 350 TPI auto car.
#5
Re: Injector Questions and Hard Start?
I found a few you tube videos on how to change the injectors but wondered if anyone has a good source for step by step instructions. Will a Haynes manual tell how to change them?
#6
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Car: 1988 Trans Am GTA
Engine: 5.7 L98
Transmission: 700r4
Axle/Gears: Borg Warner 9 bolt 3.27
Re: Injector Questions and Hard Start?
Go to the how to section, I followed those instructions and they are pretty good and step by step. Be sure to leave plenty of time for this job as my buddy and I took over a day but we took our time.
https://www.thirdgen.org/injectorswap/
The factory service manual will be much better than a Haynes manual but the Haynes beats nothing. Just be sure to get a new gasket kit, Southbay has that too. Take the time and think about any other repairs or mods you may want to do while there like EGR or maybe intake base gasket if you think yours is leaking etc.
#7
Supreme Member
Re: Injector Questions and Hard Start?
You could try ohming the injectors cold, then hot to test if they're going bad electrically. Your symptoms do sound like bad injectors.
Not sure about the Haynes manual, to swap out the injectors you basically just unbolt and remove everything attached to the plenum, take off the runners, then you'll have full access to the fuel rail. Get that off and that's as far as you need to go. It's not terribly hard, but it is time consuming and you'll want to put fresh gaskets on the plenum / runners / throttle body. There's a lot of older threads in this subforum for removing / reinstalling TPI. I wrote up some tips that might help you here:
https://www.thirdgen.org/forums/tpi/...n-secrets.html
I agree you should replace the fpr diaphragm while you're in there, and Southbay is the place to go for injectors. They have a discount code for tgo members. I also recommend spending the big money on the Delphis as they will work nicely with your stock prom.
edit: VetteSource has a nice piece by piece series on a TPI teardown if you want to see how it goes:
https://www.youtube.com/playlist?lis...FSzjNaemyMEJLl
Not sure about the Haynes manual, to swap out the injectors you basically just unbolt and remove everything attached to the plenum, take off the runners, then you'll have full access to the fuel rail. Get that off and that's as far as you need to go. It's not terribly hard, but it is time consuming and you'll want to put fresh gaskets on the plenum / runners / throttle body. There's a lot of older threads in this subforum for removing / reinstalling TPI. I wrote up some tips that might help you here:
https://www.thirdgen.org/forums/tpi/...n-secrets.html
I agree you should replace the fpr diaphragm while you're in there, and Southbay is the place to go for injectors. They have a discount code for tgo members. I also recommend spending the big money on the Delphis as they will work nicely with your stock prom.
edit: VetteSource has a nice piece by piece series on a TPI teardown if you want to see how it goes:
https://www.youtube.com/playlist?lis...FSzjNaemyMEJLl
Last edited by Komet; 01-05-2022 at 02:33 PM. Reason: added VetteSource link
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#8
Re: Injector Questions and Hard Start?
Second on SouthBay for the parts, if you want brand new injectors that are drop in and go look at the Delphi, if willing to maybe have to tune afterwards look at the refurbished Bosch 3s which are less money. Also be sure to mention your a member here, they will give you a discount.
Go to the how to section, I followed those instructions and they are pretty good and step by step. Be sure to leave plenty of time for this job as my buddy and I took over a day but we took our time.
https://www.thirdgen.org/injectorswap/
The factory service manual will be much better than a Haynes manual but the Haynes beats nothing. Just be sure to get a new gasket kit, Southbay has that too. Take the time and think about any other repairs or mods you may want to do while there like EGR or maybe intake base gasket if you think yours is leaking etc.
Go to the how to section, I followed those instructions and they are pretty good and step by step. Be sure to leave plenty of time for this job as my buddy and I took over a day but we took our time.
https://www.thirdgen.org/injectorswap/
The factory service manual will be much better than a Haynes manual but the Haynes beats nothing. Just be sure to get a new gasket kit, Southbay has that too. Take the time and think about any other repairs or mods you may want to do while there like EGR or maybe intake base gasket if you think yours is leaking etc.
#9
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Join Date: Apr 2017
Location: Northern NY
Posts: 1,116
Received 401 Likes
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314 Posts
Car: 1988 Trans Am GTA
Engine: 5.7 L98
Transmission: 700r4
Axle/Gears: Borg Warner 9 bolt 3.27
Re: Injector Questions and Hard Start?
I later upgraded to a performance tune mainly to delete cold start, emissions and give the car a bit more performance. I had no issues after but the tuner wanted to know the injectors.
#10
Sponsor
Re: Injector Questions and Hard Start?
Only difference with installing the Bosch lll's is that .you have to install them into the intake first and then the rail
#11
Senior Member
Re: Injector Questions and Hard Start?
I will also vote for bad injectors. I had the same problem, for years. Finally figured out the stock ones, were leaking down, with a hot engine, causing extra fuel in the cylinders. It would cause long engine cranks, on the warm engine. I ended up with Bosch III's 24 lb, from FIC. Check them out, they have other options if you dont want to do your own PROM tuning.
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