I had problems getting my Bosch 044 (intank) pump to make enough psi to start the engine. I hard wired it directly to the battery, and it shot right up to 50psi and started with no problems. Well I went through the shop manual and found where it said to use a jumper wire to connect the f/p and gnd terminals in the Diagnosis Connector. (discussed on page F-100 in the Fuel and Emissions section) By doing this the pump worked beautifully. What I need to know is what does this mean? What do i need to do to fix the problem? Thanks in advance guys and gals.



p.s. I tried to attatch the file, but I don't know if it worked or not.

 

Basically it means that your Bosch pump doesn't like to be run under 12 volts. You can just go into the fuel pump relay and make it a permanent 12 volts. Search for the username "Dragon" and "Fuel Pump Relay". Chris did a thread on how to do it. Works like a charm.

 

It's been in the car for quite a while now, so it has worked in the past. Should I be more concerned with why it's not getting 12V anymore? Thanks for the help Jspec, Ryan.

 

If you did the "dragon fuel relay" trick, you wouldn't have to worry! It really does work. However, you'll need to retune your driving range (take out fuel)

 

Well here's the problem. If you're talking about the fuel pump relay that sits right by the radiator, I don't have one. The spot is empty. I previous owner said something about it being wired directly to the alternator (but he couldn't remember for sure). Out of curiousity I tested the voltage going to the pump with and without the jumper wire. Both times it came up the same (10V assuming I read the multimeter correctly). So the jumper wire isn't increasing the voltage. What do I do now?????



Thanks for your continued help Jspec.

 

i had the same problem...but my pumps wouldnt come on at all.....i just did the jump wire mod ( same as you did) in the diag. box and just left it....

 

That seems like a route I'd rather not go. I guess I'm ****, but I want to find out what's causing the problem and fix it the right way.

 

Does anyone know what the "jumper wire" bypasses? Is somehing not grounded properly?

 

Something keeps drainging my battery too. I have to charge it up every few days. All I'm doing is connecting the battery too the car, checking a few things with the pumps, (maybe cranking it over and letting it run for a minute or two) and disconnecting it again. ?????

 

recgarding not getting enough volts try rewireing with a higher gauge wire to let more power through also the wire may have degraded over time. trying this as a last resort may help