high fuel pressue

[arcijack]

Gents i'm having a problem with my 6.9, my fuel pressure measures over 100 psi or beyond 7 bars. i did a return flow and i'm only geting a tablespoon of fuel after 40 second. the car idles ok. around 700 to 1000 rpm, but as soon as i give it gas, it pops and sputters, backfires out of intake and exhaust, sometimes it runs good after warming up, also it holds fuel pressure for about 10 min, and goes flat, rebuilt fuel dist, new fuel pump, rebuilt wur, gas tank cleaned and sealed, i purchased an older style fuel accumulator with the dbl fitting, but i was told to seal one end off and it would be fine. but i just ordered the correct one and also new fuel injectors. i'm getting disgusted with this car, when i think i got it figured out , it throws me a curve any suggstions would be appreciated .

 

[Helmet]

Have you checked control pressure at the top of the fuel head ?

 

[arcijack]

no sir i have not done that, i suppose you mean at the fuel diat?

 

[arcijack]

i made a mistake in last comment, i have check control pressure at fuel head, i hooked up 1 line from pressure gauge to fuel dist . and one line to warm up reg. i assume this is what you are talking about and if so reading is very high and unstabled, while the car issss running the gauge bounce around from 100 psi to 40, up and down,

 

[Helmet]

do you have the correct CIS test gauge ? Control pressure should be 3.8 bar max.

 

[arcijack]

i think so i have the bosch cis pressure gauge, tonight i pulled fuel pump , it was clean, also blew out fuel lines, and check gas tank, all clean, i will be putting new fuel acumulator on this week, but just to add tonight i notice alternator was very hot to the point i could not touch it, could this be some of the problem?

 

[arcijack]

guys i think my pressure gauge was deffective, i tried to do a test this morning, connected hose to fuel dist head and started car, the reading went to the moon and hose exploded, surely that is not normal.

 

[Oversize]

Arc is it possible for you to add pics of the gauge setup? 1000 words as they say.... BTW if no-one's said it already, welcome to the site!!! I've made quite a few friends here.

 

[arcijack]

thanks s much, i sent the gauge back to amazon, but tonight i decided to pull fuel dist. and check it out and low and behold, the regulating piston o ring was broke in several pieces, hopefffffully that is the problem, does anyony know size of o ring, the larger o ring, thanks again.

 

[motec 6.9]

Hi Arc this may help http://www.specialtauto.com/mercedes-parts/index.html .Geoff

 

[motec 6.9]

Or this http://www.ebay.com/itm/Mercedes-10...Parts_Accessories&hash=item416ac4f8e2&vxp=mtr

 

[motec 6.9]

And this is thanks to the Godfather (Styria) https://docs.google.com/file/d/0ByeM4uevgDe8VFc1dy1xSjJ4b0E/edit?pli=1 .Geoff

 

[arcijack]

thanks motec, jus what i need

 

[Oversize]

Ah the fun of having an old car! Wasn't that bad was it????

 

[Tony66_au]

Welcome to TK! :-D

 

[arcijack]

HELLO GENTELEMEN: My troubles are back, heres the spin, since my last post i purchased new fuel accumulator and damper, car starts right up runs great for about 15 minutes and starts spitting and sputturing, white grayish smoke from tail pipe and dies. foul fuel smell from intake. try to crank, will not start, but when i remove foward fuel line and relieve some pressure starts right up but quickly dies, i also noticed when i try to push down on air flow meter it is very hard. if i let the car sit for about thirty minutes, it starts and runs about 15 minutes, thus the proccess starts all over again, help, please!!!!!!!!!!

 

[motec 6.9]

Sounds like your fuel tank breather line is blocked causing vacum lock. Geoff

 

[arcijack]

Geoff you might be right , come to think of it, when i had the tank cleaned we coated it with a product called red kote and its possible that this stuff stopped the line up, i guess i will have to pull tank off and clean the line , thanks bro. that makes a lot of sense.

 

[arcijack]

gentlemen i finally traced down my high fuel pressure and low retun flow, after taking the tank out for the 4th time and blowing air through every line, the problem ended up being the inet screen on fuel dist., was stopped up, now the car runs like a champ, i want to thank all of you for being patient with me, i have learned so much from you guys, now it time to move on to suspension, need new spheres on front, soon i will be posting pictures, thanks a bunch

 

[Oversize]

Excellent news; well done!!! With our cars getting older, the fuel supply is becoming more of an issue. And it only takes one small thing to bring everything to a halt. Pics would be awesome!