another injector question....


87 with walbro 307, hotwire, adj fpr, 3" DP, tranny w/ slightly higher stall converter...

I see many different injector sizes on members cars. with this setup above, are 42.5 a good choice? Is there any reason to go bigger or smaller. Car will probably remain this way except for a bigger turbo when the stock one gets tired.

One guy told me dumping too much fuel into a fairly stock motor can actually slow it down? Is this BS?

Originally posted by cathan
One guy told me dumping too much fuel into a fairly stock motor can actually slow it down? Is this BS?


Too much fuel WILL slow a car down, whether its stock or built.

If those are your only mods the stock injectors will be fine. If you go to a TA49/TE44 turbo 36#-42# injectors will work fine.

A larger turbo than this, go 50#'s.
For what is worth,I had the stockers in last year the car went 12.77s,stock turbo,they went bad and i bought 009s(for turbo upgrade).Took the car out this year,nothing different but bigger injectors 13.20s,slow 60s...complete dog still u get going!!!
Okay, point understood.

Being presumably original injectors which at 110,000 miles are producing pretty smelly exhaust and O2 millivolts around 869 at WOT, I was trying to kill two birds with one stone by going up in pph on injectors, as they need to be replaced anyway.

From what I am gathering from you guys, and the bigger turbo could be a long time away, I may be better off getting closer- to- stock size injectors. If I am correct stockers are 28 pph. Would I be best off with someting like 32 pph? Or just better quality same 28 pph.

Certainly don't want to slow down an why waste more fuel right?
What is your adjustable FP regulator set at?

Unless you are running a thrasher chip, set the FP to 41-42 psi line off. Don't play with the FP at this point. If you get knock, turn down the boost or add octane.

Zylene or race gas can be added in small amounts to increase the octane of a tank of gas. Running a few gallons of Zylene through the tank may help the injectors.

Professional in car cleaning would run around $40-60 and would be worth it you are having a problem. Paying money for 30# injectors makes no sense.
One guy told me dumping too much fuel into a fairly stock motor can actually slow it down? Is this BS?

If you get a good chip to match your injectors, the air/fuel ratio will be correct....So, don't worry about it :) Buy 50's and get a Thrasher chip.

You have a scan tool, right ;)
FP is set at 40 line off, with 93 octane I get a few degrees of retard on shifts under hard load. Retard goes away with race gas.I keep the boost low(13 psi) on the street because I don't want to kaboom this thing.

I have had the injectors serviced before but by the smell there may be leaks, and I dont want this to cause damage.

So, I understand close to stock psi injectors is not worth the money.

I'm not sure I can swing the $ for 50's, but maybe..........heh...

Have you had the passenger header welded yet? replaced the 02 sensor lately? these are more likely a gas smell problem.

Injectors usually show up as rough idle or bucking when the converter locks at 45 mph, light throttle.
ahhh, so thats what it is!!!!! dirty injectors can cause very slight bucking at low cruising speed with the converter locked? is this a sign of bad injectors, or just dirty ones?
Yes, header has been welded and the O2 sensor is new and heated. The smell is definitely from the tail pipes.

some sources say stock injectors are worn out at 40K miles, of course those who are selling new injectors.

The symptoms aren't as obvious as those you describe, but I have occasionally started the car and had a slight "bang" from the motor along with the gas smell.....yeah, the idle quality is defininetely not great.....