fuel pump problem.. won't prime for some reason, Dr 914/George could you verify markings on China pumps please Options

[tod914]

Put in a nos bosch 3 port pump in my car after changing all the fuel lines. There is gas in both the feed and return line from the firewall to the pump.. no kinked lines there. I checked and checked my fuel line configuration. All seems good..
fat line from fire wall to step hose to filter to S / top of the pump. D line to feed into engine bay. R has the 2 return lines and the bottom of the pump. Now the pump has the correct bosch numbers on it, but does not have the S D R on it. I would think it's the same as my old pump even though it's not marked like that. fuel routing in the engine bay is fine. been over that several times. the pump turns on fine when I turn the key 1/2 way. I tried that like 30 times to try to get pressure to build up. nadda.. even tried pulling feed line in the engine bay to see if that helped. Even ran it directly from the battery for like 10 seconds like the instructions said.
Any suggestions on how to get this pump to prime/push fuel?

[tod914]

Would clamping the return feed into the pump help it get going?

[SLITS]

"R" is the one next to the aluminum cap. "S" is at the other end. "D" is the middle port. If that's how you are hooked up, it should work.

NOS means nothing ... Product was discontinued 12/2004. You figure out how old the pump is.

[tod914]

That's the way it's hooked up Ron, thanks. True on the NOS thing. Should of tried it out on a bench first.

[swl]

test to see if fuel is being delivered through the D port or through the R port. Pop off valve could be stuck which causes it to pump through the R instead of the D.

Wasn't there a thread a while back about knock off Chinese pumps that had the S and D turned around? The missing SDR labelling is odd.

[tod914]

Steve, absolutely nothing comes out of "D". Is there a way to unstick that valve your refering to? The missing labels I thought were odd too. But, oddly, it has the Bosch number and made in Germany on the bottom of the case stamped in. Also no yellow paint on the screws. Who knows, maybe it's hybrid Chinese one. I'll try swapping the "S" & "D" tomorrow and see what happens.

[detoxcowboy]

tod, please post how this comes out? yours is not marked S D R ?? I have an NOS unit to install well, supposedly it was tested but maybe you save me a headache..

[swl]

Should be easy check out. Just pull the R and route it to a collector. If that works then it probably is the check valve. Else switch S and D and see what happens.

Can't say if you would be able to recover from the stuck pop off. I had one like that and even after I disassembled it I couldn't get it to work again. The rubber tip had malformed and was causing just enough drag to stop the fuel pressure from opening the valve.

[tod914]

Great, thanks for the tips. I'll get on it tomorrow and post my results. Hope it isn't a misrepresented Chinese pump. Anyone know what kind of stamp marks the Chinese pumps have on the case?

[swl]

Dr. 914 - please pick up the white courtesy phone!

[swl]

found the thread I was thinking about.

http://www.914world.com/bbs2/index.php?showtopic=97368

[tod914]

Cool deal, I'll message Paul and see if our pumps have the same case markings.

[swl]

you know after re-reading that thread I wonder if the chinese pump really does have the innards messed up or whether it is just a stuck pop off. Note that he says the D and R are the two mixed up. That means fuel is being pumped out the R port the same as a stuck valve. Switching the leads would make it run just fine. Never could understand how the chinese could design the pump with the D and R switched.

In this thread George talks about high failure rate with the chinese pumps.
http://www.914world.com/bbs2/index.php?showtopic=96621

[detoxcowboy]

Dr. 914 - please pick up the white courtesy phone!

I have seenadvertised as "new leaky 3 port pump" (I believe it to be one of the chinese he sells too) for sale on ebay by the doctor, damn if there are bidders..

[SLITS]

you know after re-reading that thread I wonder if the chinese pump really does have the innards messed up or whether it is just a stuck pop off. Note that he says the D and R are the two mixed up. That means fuel is being pumped out the R port the same as a stuck valve. Switching the leads would make it run just fine. Never could understand how the chinese could design the pump with the D and R switched.

They reverse the postion of the valve seal assembly. Instead of opening towards the cap, it opens toward the center. Done to avoid a patent infringment? Done because of stupidity? Whatever. Could it be a Bosch pump with a Chino head?

[tod914]

I also tried running the pump with the leeds swapped (backwards) with the lines in the correct stock location. Still nothing comming out of "D". I'm kind of thinking that too Ron.. hybrid.

[tod914]

Here's some shots if you guys don't mind double checking my hookup. 1st is the line set up, then the new "hybrid?" pump, then the old bosch pump.

line set up; abit messy due to me pulling the pump off the mount



new pump case



old pump case

[avidfanjpl]

I have 2 3 port pumps - 1 Bosch in the car and a spare I got here. Thought I blew the Bosch, but I did not. Tested both last week. Both work fine.

BOSCH - it is hooked up as you show in your pic and it works.

Center hose goes back into the tank. S(upply) hose comes from tank with a filter inline pointing flow at the pump.

Hose from the engine does that triple t thing and hits the pump on the aluminum tip covered side opposite the S tip.

Think I got that right the second and third time I redid the hoses this spring.

Someone told me that the pumps do get stuck with that gate open but mine ran when on the test bench.

Hey, hit it with the right ball peen hammer, well, at least it sounds like a good idea.

Back in the 70's Fred Apgar told me that all it takes is the right hammer.

30 years later I still remember his smile, and I know he was right.

Someone here also told me these things can be taken apart and made to work again, but a NOS rebuild kit is hard to come by. I never saw one yet for sale anywhere.

J

[Tom_T]

IMHO - you're far better off with a rebuilt Bosch fuel pump from a reputable rebuilder - preferably Bosch themselves (as with the other 914 Bosch NLA bits), than with an unknown NOS unit which could've seized up or stuck valves, etc. just sitting on the shelf.

NOS = no f'ing warranty - which at least the rebuilds will have, even if short 6 mos. or so.

I know that AA is now selling a repro 3 port FP, but haven't heard how good & reliable they are, nor what warranty thy have on them.

[AvalonFal]

Yeah, I'm the one that had the crazy Chinese fuel pump. As I e-mailed Tod, the ports weren't marked and the only way it worked was to switch the D & R lines. It leaked around the connector from the start and got worse. Sent it back to AA for an exchange under George's 2 year warranty and got a made in USA (California) rebuilt 3 port. So far, so good. Ports are marked and correct, no leaks, etc, but I've not taken the car for an extended drive yet. Incidentally, the new pump also has "Germany" on the bottom of the case. Probably they just refinish and reuse old good cases in the rebuilding.

Paul