injectors from a 88 350 and i swaped them on to my 85 305tpi motor, it stared right up no codes or nothing, but when i took it for a drive, it choked a few times and hesitated to go up on rpms, then it went a way and it was driving fine, then about 40mph i stopmed on it the rpms shot up quick but i had no power behind it, and it seems to run a lil hotter than usual, im using the stock fpr on it .

any input whould be apreciated

 

Now why would you go and do that. The injectors are to big for your engine unless have someone modify your chip to compensate.

 

The LB9 (305TPI) injectors are 19#. The L98 (350TPI) injectors are 22#. You have swapped in injectors that flow more fuel, but your ECM does not know it yet. It is now delivering more fuel than it used to, but your air flow is the same. Your car is running rich (air/fuel ratio) which is probably whats causing the problems you are experiencing. If you re-tune your computer to account for the bigger injectors, then you can fix the problem with your air to fuel ratio. But unless you have modified your engine to flow more air, you might not see much of a power increase with the bigger injectors as the re-tuned ECM will just provide less fuel to generate a good air/fuel ratio. To see a power gain, modify the engine to flow more air and maximize the potential of those new bigger injectors. In any event, a re-tune will solve your problems.

 

Yes but since the prom is set for 19lb/hr injectors instead of 22lb/hr injectors it is probably flowing more than the 22. If he had 22lb/hr injectors and needed them the prom should still be set around 22.

In addition for your 305 to really require the larger injectors you would probably want to change cam, better flowing heads, large tube runners and aftermarket base.

Best advice put you old injectors back in unless you can get someone to burn you a prom. You will get no performance gain from the 22lb injectors unless your 19lb injectors are maxed out. Injectors typically do not make horsepower. It is the combination of parts you put on your engine to increase flow/efficiency that create horsepower and the injectors just feed it. Injectors by themselves will not increase your horsepower unless your old injectors are maxed out.

 

How about lowering fuelpressure?

 

That would work for WOT, but would make idle a bitch because of loss of effective spray pattern. Lowering fuel pressure causes dribbling and puddling of fuel. The correct way to do it is the shorten the pulse width by changing the injector constant and keeping the pressure up where it needs to be.

 

i have the stock fpr on there, i did this swap because im trying to elminate some problems i have with igniton and fuel, wit the 19/lb injectors i had a power loss that accuered once in a while, now it seems to auccur more often, but i have noticed these injecotrs are more quite than the 19lb ones,

even with a ram air set up , ported plenum,headers 3in cat back

basicly i wanted to see if i can eleminate a problem i though i was having but now it got kinda worse

 

Like the others have said, put your old injectors back in. The only reason for you to use the 22lb. injectors would be if you had modded your engine and the 19lb. injectors could no longer provide enough fuel. If your engine is stock, then the 22lb. injectors won't help at all, even if you change the contstant in the PROM. I would suggest you sell the 22lb. injectors, and use the money to have your 19lb. injectors cleaned. Cruzin Performance (sp?) offers this service for a resonable price.

 

Ah, that's the ticket - I calculate about static 33 psi.