Stock injectors needing deadtime for idle tune?

[lil corb]

I'm on stock 450cc blue top injectors, stock afpr and a 190lph walbro.

In order to get my combined fuel trip to +or- 2% for idle and cruising, I have to increase my dead time to 300. My air flow per rev is with in range from .25-.27 so my Maf adjustments are dead on.

Is it normal with an upgraded fuel pump to have to increase deadtime that much? Should I start reducing my global fuel % so my deadtimes aren't so high?

At what number should I be worried about having too much deadtime?

Thanks

BTW I love how user friendly Link is

 

[92AWDHX40]

If its stock whats the problem, is it running funny? They shouldnt need a tune, someone correct me if im wrong.

 

[gofer]

Upgrading your fuel pump has nothing to do with injector deadtimes, but an increase in base fuel pressure will effect how fast the injector itself can open and close. A higher fuel pressure will increase the "deadtime" of the injectors.

So, if you've got a afpr on there running a 43.5psi base then yes, you'll need to increase deadtime for the stock injectors because the stock base fuel pressure for a 1g is 37psi. I see you mentioned that your running a stock 1g fpr but are you certain its a turbo 1g fpr? The N/T 1g fpr's look similar and bolt onto the turbo fuel rail however, base fuel pressure is bumped to 47psi base.

 

[lil corb]

Upgrading your fuel pump has nothing to do with injector deadtimes, but an increase in base fuel pressure will effect how fast the injector itself can open and close. A higher fuel pressure will increase the "deadtime" of the injectors.

So, if you've got a afpr on there running a 43.5psi base then yes, you'll need to increase deadtime for the stock injectors because the stock base fuel pressure for a 1g is 37psi. I see you mentioned that your running a stock 1g fpr but are you certain its a turbo 1g fpr? The N/T 1g fpr's look similar and bolt onto the turbo fuel rail however, base fuel pressure is bumped to 47psi base.

That makes sense, is there a way to check to see if it is indeed a N/T fpr? Looks like I'm going to get a afpr a lot sooner than expected.

Am I hurting the stock injectors or anything else running that much deadtime?

Thanks gofer.

 

[gofer]

Can you take a picture of the top of your stock fpr, I could tell you by looking at it if its the turbo or N/T 1g fpr.

You aren't hurting anything running a higher deadtime or higher base fuel pressure, I wouldn't be too worried about it to be honest. Just like on the Link forums though, posting a log can tell us A LOT more than what you post and describe. I wouldn't mind looking at an idle log you've got saved on your laptop with the car warmed up.

 

[lil corb]

I will try to get them by the weekend.

Thanks!

 

[92AWDHX40]

Sounds good let us know how it goes.

 

[gofer]

Well shit, if it takes you that long then just keep checking back here. I'll have a picture of each by tomorrow afternoon for you to check and verify which one you've got.

 

[lil corb]

Well shit, if it takes you that long then just keep checking back here. I'll have a picture of each by tomorrow afternoon for you to check and verify which one you've got.

That would work better because my weekend work schedule is hectic! I will try to get a quick log monday and post it.

 

[lil corb]

I finally got around to taking pics of my stock FPR... based of the pics Gofer put up in another thread, it does seem like I have a N/T FPR.

check it out:

 

[gofer]

Damn. I knew there was another thread I was supposed to toss that picture in, that picture was actually taken for this thread, I just couldn't find it.

Anyway, looking at your picture it appears, at least to me, that you've got a turbo fpr as it doesn't look like it's been "crushed" from the center.

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[lil corb]

Damn. I knew there was another thread I was supposed to toss that picture in, that picture was actually taken for this thread, I just couldn't find it.

Anyway, looking at your picture it appears, at least to me, that you've got a turbo fpr as it doesn't look like it's been "crushed" from the center.

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haha..Thanks gofer. I knew you meant to put it in this thread too! Still confused on why I need my deadtime to be up so high with stock injectors.

Here is a quick idle log I did yesterday. Don't mind my ISC position not at 30 as it always wants to move +/-5 by itself.

 

[lil corb]

Finally got around to verifying that I do have stock injectors. INP-009 by the connector, based off of my google search. It is in fact stock 1G injector (single spray pattern).

Comes down to having a 190lph, Fuel lab FPR set at 37 psi and stock Oem injectors but needing deadtime for idle tune. Only thing I haven't confirmed if it is infact a 190lph but after research it still wouldn't matter how big because of the fpr. Is this right?

Any other ideas? Wisemen?

Even on the ecmlink forums it's a baffle.

Thanks