Adjusting Bosch 233 regulator

[Ttype6]

I know I can trust Eric for selling the correct stuff. Some of the other vendors...not so much.

Eric is the only vendor I know of who offers a disclaimer for the DW pump. He has from the beginning. If there are now others,he was the first.

 

[ITSAV6]

I have only had 3 pumps in the 24+ years I have owned my car. The stock one, the GM Sy/Ty pump,and my current Walbro 255lph. I went from 13.80's stone stock @ 15psi to 13.20s @ 20psi with the stock chip 14" cone K&N and BGC adj regulator. Went 12.30s with Reds 93 chip 20psi and Sy/Ty pump, all on stock turbo/inj/down pipe and no dump. I added the 255lph when I built my engine and added the TE61 and 55# inj.
I am sure someone would swap pumps with the OP. I just realized I have had only 2 turbos, 2 sets of injectors and 3 fuel pumps in 24 years...

 

[Anthony P]

had a good tech talk with the OP. he is checking out his fuel lines this afternoon. he did not have fuel system problems until the installation of this DW300 on a stock powertrain.

he is also going to confirm TPS and IAC settings, coilpak resistance and other initial parameters as well. suggested adding a Casper's C3I test tool to his toolbox as coilpak resistance values of 11K to 13K alone is not a complete test of the coilpak/ignition system.

procedure for TPS and IAC is here: http://www.gnttype.org/techarea/maintenance/maintpage.html

set TPS to 0.42 to 0.46 do not exceed 0.48
confirm WOT is greater that 4.50. must be greater that 4.5V for ECM to enter power enrichment mode

set IAC counts between 10 and 20
keep the value less than 30 and not bottomed out at 0

IAC screw adjustment:
CCW increases IAC counts
CW decreases IAC counts

to aid in the recording of the engine parameters, attached below is a spreadsheet template for the stock chip data seen via the ALDL connector.

 

[Tori]

Quick question.... back at the tank,.... going into fuel pump hanger assy,.... which is the return line ? I know its the smaller of the 3 (1/4" diameter)

Trying to confirm lines are going into tank correctly and didn't get swapped around when i replaced the rubber sections. Starting from the rear most pipe which is the 3/8" supply line, whats next in line (middle) and which is at the front ?

--Trying to do this without dropping the tank, and i can see the rear pipe, and the front pipe. Maybe someone has a hanger assy laying around and can ID the pipe layout.

* if i have this correct, the middle line should be the return line.

 

[Anthony P]

middle line, the smaller hardline, is the return line

 

[Tori]

middle line, the smaller hardline, is the return line

Thanks Anthony. That confirms i have the lines running correctly.

Turns out I DO HAVE A RESTRICTION in the return line. Take a look at the fitting on the hardline that runs back to the tank. The opening of the fitting is TINY. Probably only 1/8" !!! I read another post about someone opening this up by drilling it out. Anyone have any info on this procedure ?

While i had the line off, i ran the car and checked the fuel pressure. Dialed it right into 38# (vac. line off) so this clearly is the issue like everyone said. Not sure which way i'll go at this point, but now i've confirmed a few things at least. Thanks for all the help guys.

 

[Tori]

So after following a link, that led me to another link... I found where someone else had success drilling out the end of the hardline, taking it to 9/64" (which is just one drill size larger) He was using a different pump but was having the same condition.

I gave that a try on my car and got the pressure down to 49# vac line off. When raising the throttle, it would drop to 45#. If only this were "horseshoes or hand grenades"

 

[Ttype6]

The opening of the fitting is TINY.

It's called a Saginaw fitting. There's another one in the return line where it connects to the regulator. There are four of these (Larger) in the feed line. The result you received,when you drilled the fitting, is very typical.

 

[Tori]

I'm sure you know this already, the return line is 5/16" until it reaches the hard line at the cross member. I wonder if having no restriction there, by going 5/16" to 1/4" without any reduction from a fitting would be enough.

 

[Tori]

Spoke with the vendor today, he's offering to swap the DW300 for a 200. I think i may goes this route as it'll be a clean way to solve my initial issue.

From reading other posts on the DW200, looks like i won't have any issues after this.

Anyone have an reasons NOT to do this. ?

 

[626gn]

The DW200 is the pump I mentioned in your other thread. It's a good choice.

 

[Ttype6]

Spoke with the vendor today, he's offering to swap the DW300 for a 200.

I think this is the best way to go,however you could set your base pressure to 55 line off. You'd have to make some adjustments to the chip like WOT fuel and such. Doing this would help to atomize the fuel better. Try this first,then decide.

 

[TType85]

You may be way past getting the regulator but Holley makes/made a stock appearing adjustable still. https://www.summitracing.com/parts/hly-512-503-5 I have one on my car and it works fine. Not sure if it is still made.

 

[Tori]

You may be way past getting the regulator but Holley makes/made a stock appearing adjustable still. https://www.summitracing.com/parts/hly-512-503-5 I have one on my car and it works fine. Not sure if it is still made.

Hopefully i won't need that one now that i have the proper pump,..... but i like that one the best. Thanks for the link. That for sure would pass smog.

 

[Tori]

Okay..... i think i'm able to draw this to a close. Swapped the DW300 for the DW200 tonite. Checked the pressure (still have the adjustable unit i bought from a member here early on in the process) and was able to dial in 43# vac. off. It maintains steady pressure when raising RPM and even idles better now. Took her for a fresh tank of good ole' CA. 91 and gave her a few blasts too see how it held up under boost. 15# was easy, and long hauls on the skinny pedal saw 18# with no knock. I'm a bit surprised, pleasantly surprised. That's probably the hardest i've been able to pedal the car in almost 2 years of owning it.

Thanks everyone for getting me on the right track.... till the next mod....

Cheers !

 

[Ttype6]

Hopefully i won't need that one now that i have the proper pump,..... but i like that one the best. Thanks for the link. That for sure would pass smog.

You will need to increase the base fuel pressure to 43 psi for the TT chip.

 

[Tori]

You will need to increase the base fuel pressure to 43 psi for the TT chip.

I'm confused by this. Maybe i don't know what base fuel pressure is, but in my last post i stated i had it at 43 with vac. off. Is that not correct ?

 

[Boost231]

Yes

Sent from my SM-G935T using Tapatalk

 

[Tori]

Yes ? yes, that's not correct ? can you elaborate a bit. that's not much help

 

[Pronto]

You're good. Static is pressure with the vac line off. TT chips are designed with 43 line off as the normal or starting poiint. Glad you got this worked out. Have some fun now.