Injector size?

[Holshot]

Can anyone tell me what size injectors come stock in the 2L motor? I've read quite a bit of literature on the stock turbo cars that they ran lean and knocked when these things were new off the showroom floor. The gentleman who's blog journal I came across said that above 4500rpm that the injectors were at near 100% duty cycle. I plan on going to a slightly larger injector to help with this issue and add a little bit of a safety net. Unfortunately he does not mention anything on what size stock came on the car or what he upgraded to.

Also, does anyone know what the stock Fiat fuel pump flows? I did my best with searches and I couldn't find anything that showed flow rates on either so any help would be much appreciated. And I suppose one last thing while I have it in my head for the tech gurus of the forum that might know and who might be reading, what is the stock fuel pressure at idle and are our fuel pressure regulators rising rate? Or does it stay static? If it's rising rate how does it work? My experience with the Aeromotive regulators which were rising rate used boost as its reference and you could get 1 to 1, 5 to 1 ect... But obviously a stock NA fiat sees no boost, so school me on how the regulator works on this car. Thanks in advance!

Kind Regards

[RRoller123]

I had one gentlemen here indicate that the stock injectors can inherently pass enough fuel, and that the easy installation/addition of a variable resistor could fool them into the increased flow needed. I haven't gotten to that step yet in my build but maybe others could comment on this. Saves a lot of cost if the injectors don't need to be changed to hop up the engine somewhat (for street use).

[wizard124]

You can check volume pretty easily. Pull the coil wire. Remove the fuel line at the cold start valve. Have a helper direct the flow into a quart jar while you crank the engine.

I couldn't find a spec. When I did this, I got about a pint in about 20 seconds. You'll know if you have a blockage if it is only a trickle.

Holshot, I tested the fuel pressure in the CSV line, hopefully I wrote it down somewhere or can find the spec for you.

Have you got the engine running?

My manual states: Fuel pump output should be 39-45 psi. Regulated pressure should be 33-39 psi at idle.
When I ran my test I had 28-32 at idle, 28-30 at 2000rpm, 29 at 3000 rpm. On engine acceleration, It hit 40 psi.
Maybe this answers your question on the type of fuel regulator

My manual from Brookland Books, has some pages devoted to turbos. Probably worth obtaining it

[BEEK]

0-280-150-214 flows 17.9 lbs / hour, 188.1cc / min 40.5- 32.7hp @95% duty cycle

0-280-150-128 15.9 lbs / hour 167.1 cc/min 36.0-29hp @95% duty cycle

0-280-150-114 18.1lbs/hr 190.2cc/min 40.9-33.1hp@95% duty cycle -- this is the stock lancia 2.0 efi injector

the hp numbers are dependant on efficiency in the engine, the high number is for a higher compression race type motor

if you can give me a injector part number, i might be able to give you specs

[vandor]

> said that above 4500rpm that the injectors were at near 100% duty cycle

The injectors need to be at 100% duty cycle around the torque peak, as that is when the engine is most efficient ie. pulls in the largest volume of air per stroke. The Spider's torque peak is at 3000 rpm.
Are you going to use a turbo? If not, stay with the stock injectors. If yes, then use programmable FI with larger injectors.

[Holshot]

I have to disagree Vandor, injectors should never be run at 100% duty cycle. Everything I've ever read says you want to run injectors at 80/85% duty cycle max. I've built quite a few fuel systems in the past on my other cars and always followed that rule with great success. Again, you never want to that close on the razors edge when it comes to fuel. You should always have a safety margin especially when dealing with Forced Induction because so many factors can change at any moment. In NA applications you're a little safer but none the less still want to give yourself extra room as needed.

Thanks Beek! Nice to have some concrete numbers to work from... I have a Delta Intergrale HF intake manifold with fuel rail and injectors on the way from Germany! Took forever to find something and hopefully he got it in the mail today as promised because I can't wait to get my hands on it. I plan on doing all new AN fittings and braided lines so I'll be hacking off the ends of the stock rail and welding on the AN fittings and that way I can use an Aeromotive fuel pressure regulator. As soon as it gets here I'll post up part numbers assuming they are stamped somewhere on the body of the injector. Thanks again!

Thanks Wizard, I appreciate all the advice and the numbers provided!

[vandor]

Hi Giuseppe,

You are totally correct, poor wording on my part. I should have said 'highest duty cycle', to indicate that it's at the torque peak when there should be the most fuel injected.

[Holshot]

Gotcha Vandor... Another question comes to mind that I haven't seen through my searches to anyone that might know is what brand/style injector are they (denso, weber, delphi, lucas, ect...) and also what type of injector are they, ie. low or high impedance?

Thanks

[FiatMac]

The injectors on my '82 are Bosch 280150121. I also had an '80 parts car that had the same injector. I think that this is the one that was most often used by the factory for the 2000 Spiders. Information I have seen says 16.75 lb/hr at 43 psi. Craig Nelson (ga.spider) on this site had a set of '82 injectors cleaned and checked by OK Injectors. They ran tests on the cleaned injectors and provided flow data. They flowed 17.95 lb/hr but I don't know the test pressure they used. Craig was chasing a problem on his car at the time. He posted info in thread linked here. http://wwwe.fiatspider.com/f08/viewtopi ... =5&t=20853

I have also seen reference to a Lucas injector. I will have to dig into my data to find the Lucas number.

[FiatMac]

The injectors are low impedence...approximately 2.4 ohms if I remember correctly.

[FiatMac]

The Lucas Injector reference I had for the Fiat Spider was 5204001.

[BEEK]

The Lucas Injector reference I had for the Fiat Spider was 5204001.

lucas = prince of darkness
the reason english people drink warm beer is they have lucas referigerators
the 3 positions of a lucas light switch = dim, flicker and off

[aj81spider]

lucas = prince of darkness
the reason english people drink warm beer is they have lucas referigerators
the 3 positions of a lucas light switch = dim, flicker and off

And to totally derail the topic:

The president of Lucas went to his engineering staff and demanded that they produce some electrical product that didn't suck. The engineering group thought about it a while then came out with a vacuum cleaner.

[Holshot]

Thanks Stan! Great information as always from everyone on the forum... I really appreciate all the help and knowledge gained from the forum.

[DocGraphics]

A.J. I appreciate a sense of humor & that was great!!! Didn't suck..hahaha

Come on guys.. not to knock Lucas but that was funny there