Skulltrail

Hey all! I have a 88' IROC-Z with the 305 TPI motor. I have to change the fuel injectors to fix my long cranking situation, and I was wondering what you guys would recommend. I read on the "Recommended TPI mods" page that an adjustable fuel pressure regulator and higher flow injectors can improve power and fuel economy. However, it does not specify whether or not this applies strictly to the 350, or if it applies to the 305, as well.

If so, what would you guys recommend I do? Thank you all for your help. I tried searching this stuff up but I've not been able to find anything. The motor is completely stock and being able to squeeze out an extra 1 or 2 mpg while also fixing a problem would be pretty epic.

thtanner

iTrader: (1)

I wouldn't suggest an AFPR or 'high flow injectors' on a stock setup.

Installing new injectors to replace 3 decade old ones isn't a horrible idea really. Install a new diaphragm on the FPR, new fuel filter, and make sure your ignition system is all happy. That'll keep your car running right.

KyleF

An adjustable fuel pressure regulator can't hurt and can only help. Worst case scenario is you spend money and find out the car runs best at factory fuel pressure. However, to really find out if one helps or not, you will need to be data logging and watching BLM and INT values. Higher pressure can net a better spray pattern depending on injector. Lots of us are running them, and I am adding one to see if a few PSI can make some difference on my set up, but I am not stock.

On the injectors... you need to do some reading. The Bosch IIIs are known to be a good replacement, but some have reported idle quality issues and you will see that some tuning may be required... but they are pretty cheap. Delphi's are known to be drop ins but are 3Xs the price.

I would call south bay and explain what issues you are having and where you want to go with modifications and power levels and let him hook you up with the right injector. If I was in your shoes, I would go with the Delphis. The Extra money is worth he peace of mind if you are staying close to stock. There is a lot of information around here if you search. You do not want to change Flow Ratings (Pounds per hour) if you are not planning on getting a chip burned.

thtanner

iTrader: (1)

I have the Delphis, and I must say, they are a welcome change from the Bosch IIIs. So... quiet... just not sure if they have a 19lb version?

So I do second the Delphis for 350 cars. I just don't really think throwing an AFPR on a properly running stock car is gonna do much, but he can grab an ALDL to USB/BT to watch the data stream and adjust, as you suggest.

A heated o2 would be a good "quality of life" upgrade, definitely helps idle.

vinny R

Get the Delphi's from south bay and call it a day! I used them on my car and you will get a small increase in overall performance with just swapping to these and absolutely no tuning, noise or idle issues. Southbay has a code I think it is TG11 and you will get a 10% discount.

southbay08

Yes we do have the 19lb delphi's in stock. You can either give us a call or order them from the website. If you do go through the website you will need to pay with a credit card not paypal. For the past year or so
paypal has not been able to process the transactions with the promo code...there's some kind of glitch. However there is no problem with a credit card. If you would still like to use paypal we can always send you an
invoice that will include the discount.