MicroSquirt.com read only forum (Jan.15,2018)

It is my understanding that the low impedence injectors do have quicker open/close times, and that may wind up helping you.

I know of one person running 72 lb/hr injectors on a 3 liter 6 banger and his idle is fine, bu thtey are low impedance and he is running MAF on a Nissan 300ZX computer.

I am running 750cc injectors on a 2.3L Ford. I see 1.2 and 1.3 ms idle pulse widths and still seem to have fine idle control. I would not attempt this without MSII high res.

I would keep fighting with yours a little. If 750cc will idle on a 2.3 then 550cc should idle on a 1.6.

Just as a side note I am running into the 70% duty cycle at 425 hp. The goal is 500hp so I will just edge in there with maybe a little extra fuel pressure.

Thanks for the replies guys. I tried lowering the injector time in small increments down to .5 ms with no improvement. To be absolutey certain, I will swap the 550s in one more time and try again. I'll post the results.

Mike

460,

I would like to compare your idle PW calculation to the one I listed on the first page of this thread. Can you tell me the following information about your setting?

Required Fuel value?
Idle VE value in the base fuel table?
The approx. vacuum at which your engine idles?

Thanks.

Mike

I'm running a 16v with MS1, and with 440cc injectors, depending on IAT, my idle AFR ranges from high 11s to mid 13s .....if I try to make it any closer to stoich, my PW drops to 0 on occaision, yup, 0. It seems that anything below 1.2ms and my PW just goes to 0, so IAT adjustment will pull it lower than the IOT. I've ran anything from 0.8ms to 1.3ms IOT and it doesn't make any difference in the sub 1.2ms stumble, the only choice was to idle the engine artificially rich.

I think with hi-res code you should be able to get idle fairly decently with 440s, but I agree, 550s would be safer for top end.

Neil

460Stang:

What injectors are you using? Brand/Impedance

For those of us with turbos and big injectors, this kind of information is very helpful to share - the brand/type/impedance can play a big part in how quickly the injector can cycle and use the resolution of MSII.

Good question! They are packaged by a company called VENOM and are high impedance (the coils measure around 14 ohms with a DVOM).

Mike

at some point in time I switched from 2 squirts alternating to 4 squirts ...doh. So now that I'm at 2 squirts I can dial my idle to 16+ AFR with no hiccups, and no more stutters when enrichments try to pull down the PW. I'm very happy.

Oh, and the Venom injectors, I've honestly heard that they don't have a great track record, I recently saw a post on the homemadeturbo forum where a guy swapped his venom's for RCs and all his problems went away.

Neil

Mike Braddock wrote:Good question! They are packaged by a company called VENOM and are high impedance (the coils measure around 14 ohms with a DVOM).

Mike

Venom injectors are not known for their high quality.You may want to take them to a injector cleaning place and have them checked.