Stock tune with bigger injectors questions.

[bgbmxer]

88t1 pbody long story short I had gunked up injectors so I had a newer set numbered 5277895 which are 32 pph and the stock injectors would have been 27pph. To get my afr into the14s at idle I have to turn the fuel pressure down to the 20s. I'm looking into getting a cal scaled for these injectors just didnt think I'd have to turn the fuel pressure down so much. Does this seem right?

[87blueshelbyz]

According to the thedodgegarage.com the 5277895 are 33 pph.

[bgbmxer]

According to the injector guide they suppercede a few different types some were 32 and yes some were 33

[John B]

What are the potential problems with low fuel pressure to compensate for bigger injectors? Poor idle?

[bgbmxer]

What are the potential problems with low fuel pressure to compensate for bigger injectors? Poor idle?

Im unsure honestly. I would think that the spray pattern wouldn't be the greatest at some point tho.

[wallace]

I ran +40's on a stock tune with lowered fuel pressure. I had hard hot restart issues in the summer here in va. Yrmv

[bgbmxer]

I ran +40's on a stock tune with lowered fuel pressure. I had hard hot restart issues in the summer here in va. Yrmv

I had the same issue the other day. Car sat for about 20 minutes and then tried starting it and it wouldn't stay running. I honestly think from the heat soaking from sitting the fuel is trying to vaporize. Once the pressure is up it seems fine again

[wallace]

Yep you are much more susceptible to vapor lock with the lowered pressure since the fuel boils at a lower temp with reduced pressure. Same principle as a cooling system.

[5DIGITS]

As previously indicated, the vapor lock issue is a problem along with poor atomization and the resulting port wall wetting, inconsistent fuel delivery (pulse to pulse), and how this can all make for very unstable adaptive fuel control.

[bgbmxer]

Great info. Gonna get a custom cal and that should solve it

[GLHS60]

Wouldn't a T-II SMEC be a reasonable solution?

Thanks
Randy

[bgbmxer]

Wouldn't a T-II SMEC be a reasonable solution?

Thanks
Randy

from what I'm told the boost control from t1 to t2 is different. Also I don't have a charge air temp sensor either.

[wallace]

The charge temp is easy to do. You just add one pin at the ecu and the other lead is grounded.

[bgbmxer]

I know the wiring is easy but its the stock intake and not setup for the charge temp sensor. I could probably switch some things around and use the one vac port from the intake for the CAT sensor

[5DIGITS]

The charge temp is easy to do. You just add one pin at the ecu and the other lead is grounded.

Well said - after a donor connector and related wiring is located, the upgrade is a rather easy task.
Do yourself a favor and acquire a 'caged' sensor to improve temperature response and fueling accuracy.

from what I'm told the boost control from t1 to t2 is different. Also I don't have a charge air temp sensor either.

This is correct.
The 88 and later T-I used a 'PAR' system that achieves the minimum boost if disconnected while the T-II maintained a system that caused full boost, if the solenoid failed.
This was a turbo/head-gasket durability fix and also highlights the fact that two entirely different groups were designing/calibrating the T-I VS the T-II.
It's clear from the diagrams below that the T-I will supply 100% of the compressor pressure to the WG actuator if the solenoid fails to open.
On the other hand, the T-II will supply nothing to the WG actuator if the solenoid fails to open.
This is why the duty cycle tables for each application are inverted and why the related plumbing needs to be correct for boost control to function properly.

[bgbmxer]

I'm running a g valve anyways but figured those were the differences.

[5DIGITS]

I know the wiring is easy but its the stock intake and not setup for the charge temp sensor. I could probably switch some things around and use the one vac port from the intake for the CAT sensor

It can be added upstream of the throttle body if you want to avoid drilling the intake.
Although, if you remove the throttle body (or lock it wide open), remove the intercooler or turbo hose, pull the valve cover, insure all the valves are closed (via cam or follower removal), and connect air pressure to the PCV intake nipple; the charge temp sensor hole can be drilled and tapped while the debris is blown out the throttle body hole.
I strongly suggest using carb or brake clean through the intake prior to any of this being done.
This will minimize the oil residue in the intake and minimize the materials tendency to stick to the intake walls.

[bgbmxer]

It can be added upstream of the throttle body if you want to avoid drilling the intake.
Although, if you remove the throttle body (or lock it wide open), remove the intercooler or turbo hose, pull the valve cover, insure all the valves are closed (via cam or follower removal), and connect air pressure to the PCV intake nipple; the charge temp sensor hole can be drilled and tapped while the debris is blown out the throttle body hole.
I strongly suggest using carb or brake clean through the intake prior to any of this being done.
This will minimize the oil residue in the intake and minimize the materials tendency to stick to the intake walls.

isnt the upper hole where the vacume line comes off the correct size?

[5DIGITS]

isnt the upper hole where the vacume line comes off the correct size?

Do you have a single or two piece intake?

[bgbmxer]

Do you have a single or two piece intake?

1 piece