Injector question
Thread Starter
8th Gear
Joined: Jul 2012
Posts: 8
Likes: 0
From: Iowa
Injector question
Bought a 88 l98 auto , having some issues. car will not not spin tires 
Checked fuel pressure , good pressure but not holding via shop manual pinched off pressure hose not sure if i had it pinched off enpugh kinda hard to get to but pressure still drop but real slow tried pinching off return line and pressure drops . So either leaking injectors or fuel pump going to replace everything with the car having 105k on it and looks like most everything is original like the plug wires were , so who knows what kind of life the car has had.
Question is what size injectors can i go up to on the stock motor. And aslong as im replacing injectors what other mods should i do while doing that (fuel pressure regulator etc...) Thinking about buying a chip also.
Checked fuel pressure , good pressure but not holding via shop manual pinched off pressure hose not sure if i had it pinched off enpugh kinda hard to get to but pressure still drop but real slow tried pinching off return line and pressure drops . So either leaking injectors or fuel pump going to replace everything with the car having 105k on it and looks like most everything is original like the plug wires were , so who knows what kind of life the car has had. Question is what size injectors can i go up to on the stock motor. And aslong as im replacing injectors what other mods should i do while doing that (fuel pressure regulator etc...) Thinking about buying a chip also.
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 763
Bought a 88 l98 auto , having some issues. car will not not spin tires Checked fuel pressure , good pressure but not holding via shop manual pinched off pressure hose not sure if i had it pinched off enpugh kinda hard to get to but pressure still drop but real slow tried pinching off return line and pressure drops . So either leaking injectors or fuel pump going to replace everything with the car having 105k on it and looks like most everything is original like the plug wires were , so who knows what kind of life the car has had.
Question is what size injectors can i go up to on the stock motor. And aslong as im replacing injectors what other mods should i do while doing that (fuel pressure regulator etc...) Thinking about buying a chip also.
Checked fuel pressure , good pressure but not holding via shop manual pinched off pressure hose not sure if i had it pinched off enpugh kinda hard to get to but pressure still drop but real slow tried pinching off return line and pressure drops . So either leaking injectors or fuel pump going to replace everything with the car having 105k on it and looks like most everything is original like the plug wires were , so who knows what kind of life the car has had. Question is what size injectors can i go up to on the stock motor. And aslong as im replacing injectors what other mods should i do while doing that (fuel pressure regulator etc...) Thinking about buying a chip also.
Last edited by Joe C; Jul 4, 2012 at 09:22 PM.
Le Mans Master
Joined: Jul 2007
Posts: 5,356
Likes: 2
From: No HOA, New Hampshire
Cruise-In X Veteran
St. Jude Donor '09
Bought a 88 l98 auto , having some issues. car will not not spin tires Checked fuel pressure , good pressure but not holding via shop manual pinched off pressure hose not sure if i had it pinched off enpugh kinda hard to get to but pressure still drop but real slow tried pinching off return line and pressure drops . So either leaking injectors or fuel pump going to replace everything with the car having 105k on it and looks like most everything is original like the plug wires were , so who knows what kind of life the car has had.
Question is what size injectors can i go up to on the stock motor. And aslong as im replacing injectors what other mods should i do while doing that (fuel pressure regulator etc...) Thinking about buying a chip also.
Checked fuel pressure , good pressure but not holding via shop manual pinched off pressure hose not sure if i had it pinched off enpugh kinda hard to get to but pressure still drop but real slow tried pinching off return line and pressure drops . So either leaking injectors or fuel pump going to replace everything with the car having 105k on it and looks like most everything is original like the plug wires were , so who knows what kind of life the car has had. Question is what size injectors can i go up to on the stock motor. And aslong as im replacing injectors what other mods should i do while doing that (fuel pressure regulator etc...) Thinking about buying a chip also.
Slow down, one thing at a time. Your Vette isn't a tire burning race car. Even when running perfect you might get a chirp. If you want to smoke the tires, install cheap Goodyears, a line-lock, and pour bleach around the rear tires.
IMHO the last thing I would want my tires to do is to break traction and leave me spinning off the road. Leave the drifting to the Hondas
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
Your L98 can put out plenty of power in stock form. Maybe only 230/240hp but 330lb/ft torque. Get a complete tune up, check fuel pressure key on at 43psi and it will probably drop to around 35 to 38 psi at idle. If you have this, then you are probably okay. If you do change your injectors, then you will need to get your chip reburnt. It is best to get the car dyno tuned. Your car will spin the tires easily if it is in proper working order. 
Thread Starter
8th Gear
Joined: Jul 2012
Posts: 8
Likes: 0
From: Iowa
Not that im wanting to buy tires all the time. i was just surprised that it couldnt from a dead stop and can barely do it by brake standing. eventually i will turn the vette into a drag car for the local 1/8 mile track, but not till im done restoring my 69 camaro bought the vette to have fin with till then . just figured if i needed to replace injectors to maybe go ahead and put something a little bit bigger on now if possible.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The ECM will adapt to the larger injectors with a net gain of zero. There is no point in going to larger injectors.
In fact, if the injectors are too large the ECM will hit the limit of its compensation and you'll run rich at idle.
In fact, if the injectors are too large the ECM will hit the limit of its compensation and you'll run rich at idle.
