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Posted by: 914_teener Jun 25 2011, 06:39 PM

So after re-habing the whole D-jet system including a beautiful Bowlsby harness and rehabing and checking ALMOST every other FI related part on my car fired it up a couple of weeks ago. Keep in mind I had driven my car for a couple of years with no major problems until my MPS went out.

Well just couldn't get the car to idle right and then it would stall and flood......besides I noticed it seemed to be running rich.......MPS right????? It is brand freaking new! Did I check all the vacum leaks.....Couldn't figure it out...spent hours after work at night in the garage, checking resistance on CHT ect ect......last night after no success I decided F...it I need to start over and check the parts I haven't looked at or tested yet....since the car ran great before....I figured I didn't need to. WRONG...WRONG.....WRONG... NEVER ASSUME that A PO has done something right!

Started with the mechanics...compression...spot on 130 each cylinder...hmmmm fuel pressure...didn't have a gauge. Harbor Frieght 29 bucks.

Fuel pressure......45 freaking pounds!

That was it....idles like puss!

Going to get a beer now.

Moral of story:

Be smart, and listen to and learn from others and don't assume the person before you did it right.

Rob

Posted by: Tom Jun 25 2011, 07:32 PM

Good job!!!
Now you are a D-jet guru. LOL!
Tom

Posted by: simonr Jun 25 2011, 07:58 PM

I got a great quote from Jake Raby" Verify everything" And "Are you SURE" low and behold my timing mark was wrong and I had it set at 54 degrees btdc. My fan had two timing marks .No wonder it was pinging at WOT . I was not SURE. Live and learn Validate and verify EVERYTHING

Posted by: skaufmann Jun 27 2011, 11:03 PM

More fuel pressure = more power no?!?

Posted by: SLITS Jun 28 2011, 07:00 AM

Somewhere above, say 35 lbs, the injector stays open (leaks) and causes a very rich mixture. Fuel pressure overrides the solenoid & spring's ability to shut off the fuel.

Posted by: Cap'n Krusty Jun 28 2011, 07:59 AM

No.

The Cap'n

Posted by: sean_v8_914 Jun 28 2011, 08:40 AM

nice work!
brad (paul) Anders has a check list on his d jet site. it is easier and FASTER to just go down teh list, check everything rather than trouble shooting. then I go over the hose diagram.
I do mechanical, hoses then brads list
and for teh record: correct D jet fuel PSI is...?

Posted by: Cap'n Krusty Jun 28 2011, 09:48 AM

2 Bar, 29.4-30 PSI.

The Cap'n

Posted by: RFoulds Jun 28 2011, 01:01 PM

How did you correct the pressure? Was it a bad pressure regulator??

Posted by: Jake Raby Jun 28 2011, 03:30 PM

ASSUME that nothing is correct and quantify everything.

The first and biggest rule in mechanical manipulation. If you didn't do it yourself, it didn't happen.

Posted by: aircooledtechguy Jun 28 2011, 04:12 PM

I'll second that one!!

Clients bring stuff in all the time swearing that they checked the basics. . . From my experience, it's usually the basics!!

Posted by: Kraftwerk Jun 29 2011, 08:35 AM

What did you do to lower the fuel pressure?

Posted by: 914_teener Jun 29 2011, 08:43 AM

Adjusted the regulator per the Hayes manual...28 pounds psi...backed out the lock nut and spun it out until it was spec. Pretty easy.

Posted by: Ductech Jun 30 2011, 05:11 PM

This applies everywhere..... can't tell you how many customers would have there bike towed cause they forgot they flipped the kill switch.....put the key in and it didn't start.... got start from the bottom then go up from there.