hey guys ,,back again with a new issue ,,i have a 93 dak 4x4 3.9 engine ,,replaced the fuel pump a couple times and it's been running pretty good lately,,this morning i go out to start it and it cranks but wouldn't start ,,sprayed some starting fluid in it and it started and ran till the starting fluid was gone ,,tried to restart afterward same problem ,,squirt some starting fluid and starts right up,,went to the haynes manual and reading thru it found it has a pressure regulator on the fuel rail,,put a pressure guage on to check for pressure and the haynes manual say to disconect the vacume line to check pressure ,,ok did that and tried to crank it and it fire right up 40 lbs of pressure at the valve steady ,,running ,,when i reinstalled the vac line pressure dropped to around 36lbs jumpy ,,truck runs great with the vac line disconected and plugged and will run with the vac line connected also now ,,do ya think it sounds like a bad regulator ?? called around and it's a 75 buck part and i sure hate to replace things i don't need to replace ,,also will it hurt to drive it without the vac line connected ? till i get the cash to replace it if needed ,,it's never really got good gas mileage since i've owned it and 10 mpg is proably the best i have ever gotten if that says anything ,,this really has me stumped and i really don't look forward to replaceing another fuel pump,,lol,,lol,,
thanks in advance and i know if anybody can help you guys can,,
crazy

 

Yes you can drive with out the vacuum line hooked up to the regulator. All it does is keeps the fuel pressure down during idle and low RPM. When Higher RPM the pressure regulator releases more pressure to help feed the engine. So you may be running a Little rich at idle or low RPM's.

 

hey guys and the other crazy4x4,,got er done ,,and guess what it was ??the notorious wires under the fuze block,,read thru some other posts before i went out and tried the truck again and it did the same as before ,,so i figured before i go buy more parts i'm gonna check those wires again,,i fixed them already once this summer so wasn't really giving them any thought as to them needing fixed again,,so i tore the entire wireing harness apart again and sure enough the wires were coroaded,,cleaned and re solidered them then coated the entire job with hotglue to seal them good ..tried the key and it started up and ran like a new one ,,fingers crossed that it will keep running,,lol,,thanks again for always a great site!!
crazy

 

Cool! Easy job!

 

hello again,,well ran fine yesterday,,shut it off.. sat in the garage overnight and went out this morning and same issue,,with same results ,,wouldn't start ,,pump isn't running,,tried the kick the pump routine still nothing,,deceided to pull the relay out and swap it with another relay,,hit the key and it fired right up and pumps running when key is on,,shut it off and replaced the original relay and started right up,,with the old relay,,what the ?????,,deceided to trying pulling codes,, on off on off on,,flashed 1-2,3-2 then 5-5 done,,still starts right up,,i'm pulling hair out trying to figure whats up???????any suggestions,,seems if i do something to it ..it starts and runs fine ,,just pretty annoying trying to figure out what to do next,,lol
crazy

 

You just got to get a meter and see what is getting power and what isn't.

 

ok thats exactly what i want to do ,,can i check for power at the relay? which terminal should get readings with the key on?
crazy

 

on the faq section for checking the asd relay it says "check for good around on ter 85 while holding key in start position",,is ter 85 for checking the ground with the key in the start position,,i want to be sure i'm checking the right things ,,what should the reading be for ter 85??
crazy

 

I had this EXACT problem which left me stranded twice. Dealer automatically "diagnosed" fuel pump but I knew it was getting 12v back to the pump. I found out the wire harnesses are junk, they corrode and decay inside the insulation. WHat I did was to bypass EVERYTHING and run a hot wire from the fuel pump right to the interior fuse block to a keyed fuse. Turn the key on and the pump gets power. I haven't had any problems with it since. Only thing is different you have to give it a few seconds each time you turn the key before cranking to build up pressure.