Mustang 5.0 injectors on an M20? (Questions)

[Rollinshake]

Ive been looking around and im seeing that a lot of people use the 19lbs-ers out of the late 80s early 90s 5.0. The reason im changing my injectors is because im having a sputtering issue thats not caused by my spark and is not caused by my fuel pressure so therefore injector problems. My question is has anyone on here ever tried these? How does the car run? Was there decrease or increase in mpg/hp? Is it plug and play on the 1986 325E, running motronic 1.1? Is it a better choice than stocks? Would you recommend anything else?

[essi1553]

If your staying stockish, message MEPEH:

http://www.r3vlimited.com/board/showthread.php?t=266477

I got a set of his 18# 415's.

[mpowerful]

The mustang injectors are generation II bosch injectors whereas your car has generation I style injectors. The GenI injectors have one pintle nozzle which pretty much makes them shoot gas like a hose. The GenII injectors are a four pintle design and will provide a better fuel spray.

http://www.youtube.com/watch?v=VfynoxL2RZI

As far as sizing. I am guessing your car is an I car with stock 14lb injectors running at 3 bar. The Gen II and gen III bosch injectors will run at almost 19lb. Although both of these injectors will run in a stock car they will run rich for a while until long term fuel trim kicks in and adjust them, and even then they will be at the end of of their adjustment range. I would say it is adviseable to run them with a chip to offset the fuel so that motronic isnt at the end of its adjustment range. An alternative might be the 17lb GenIII injector which will be a bit closer to stock injector size if you dont want to upgrade the chip as well.

How do 19lb injectors run in our cars. I have stock m20b25 with now 134k miles. I have run the genIII 17lb and 19lb injectors both with stock tune and with tune set up for the injectors. I find that both ran a bit rich with no chip. Running either of these genIII with a chip resulted in both better gas mileage and better driveability. Car felt stronger, had definite better response, and part throttle bogging has disappeared.

[mpowerful]

If your staying stockish, message MEPEH:

http://www.r3vlimited.com/board/showthread.php?t=266477

I got a set of his 18# 415's.

The 415s are 17.5lbs at 3.5 bar...........

People often overlook the fact that the injector is rated at 3.5 bar since the e36 fuel system runs at 3.5 bar. Our fuel system runs at 3 bar. This makes a significant difference. This will put you right at 15-15.5lbs at 3 bar with these injectors. They are an upgrade and will deliver fuel better than genI though. This would be the closest thing to a stock flow rate in an upgraded injector that you can get.

[Bullet Ride]

I used a wideband O2 sensor to monitor AFRs after swapping over to 19lb injectors on a factory tune. After a few miles of driving they were pretty much dialled in to what they were with the stock injectors.

[mpowerful]

Yes they will be. I wont argue that. But it will be near the limits of what motronic can adjust for. If you start out centered you leave room for adjustment based on temp, elevation, yada yada.

[Bullet Ride]

Yes they will be. I wont argue that. But it will be near the limits of what motronic can adjust for. If you start out centered you leave room for adjustment based on temp, elevation, yada yada.

Fuel trims don't need to be adjusted with temperature. The intake air temp sensor compensates for that.

[mpowerful]

Tell that to my e30. Fuel trim fattens up with the cold regardless of the temp sensor. Temp sensor in spec. Car runs richer, gets worse mpg. Soon as temperature drastically changes upward (In new orleans from say 30f to 60+f in a day) it will pop fuel through the cats for a day due to being adjusted rich. Pull plugs, definitely smudgy. I dont need a wideband to tell me that the car has adjusted its fuel trim to rich side. Cold air=dense air= more fuel.


PS: Assuming my o2 sensor is working properly. With 70+ weather I get 19 or so mpg in city with 19lb injectors and my chip adjusted to run them. In cold weather (60-65 or below seems to be where suffering starts) i get around 15 mpg. m20 is in perfect condition.

[jlevie]

Ive been looking around and im seeing that a lot of people use the 19lbs-ers out of the late 80s early 90s 5.0. The reason im changing my injectors is because im having a sputtering issue thats not caused by my spark and is not caused by my fuel pressure so therefore injector problems. My question is has anyone on here ever tried these? How does the car run? Was there decrease or increase in mpg/hp? Is it plug and play on the 1986 325E, running motronic 1.1? Is it a better choice than stocks? Would you recommend anything else?

There are several other reasons for sputtering that don't involve the injectors. More diagnostic work is indicated. Throwing parts at the problem while hoping for a favorable outcome seldom works.

[jlevie]

Tell that to my e30. Fuel trim fattens up with the cold regardless of the temp sensor. Temp sensor in spec. Car runs richer, gets worse mpg. Soon as temperature drastically changes upward (In new orleans from say 30f to 60+f in a day) it will pop fuel through the cats for a day due to being adjusted rich. Pull plugs, definitely smudgy. I dont need a wideband to tell me that the car has adjusted its fuel trim to rich side. Cold air=dense air= more fuel.

Intake leaks will cause this. As can an aged O2 sensor (replacement interval is 100k).

[Bullet Ride]

PS: Assuming my o2 sensor is working properly. With 70+ weather I get 19 or so mpg in city with 19lb injectors and my chip adjusted to run them. In cold weather (60-65 or below seems to be where suffering starts) i get around 15 mpg. m20 is in perfect condition.

That sounds a bit low. I was getting about 21-23mpg combined in 70+ weather. Even my 2.8L stroker gets about 21mpg.

[mpowerful]

Im a throttle heavy driver. What can i say. If anything my o2 is getting to be past its prime. I actually have a new one that i can throw in there this afternoon for ssss and ggggs. No intake leaks.