LongDuck

Haven't seen anything back from you on the boards regarding the fuel pump issue that we were discussion and had met to try and troubleshoot.

Any new information, or leads on fuel pumps? For those following along, this was an 85SE that was getting really great gas mileage (20C/30H), and then would stall out at 3500rpm for intermittent periods of time. Turn ignition key off, back on, and the problem would go away, or return shortly thereafter.

Very odd - and want to make sure you're making progress,

Feds

Hmm... Vapour lock of some description?

What was the power like on the car? An air pocket in a fuel line could mean less than expected fuel getting into the chambers (good mileage), the stalling when the bubble fills the whole line.

SimRX-7

hey LongDuck... sorry i havent gotten back so quick.

in a few days i should have a fuel pump coming in from kansas(one of our board members) and will go from there.

basically the poor girl has had to watch me leave on a motorcycle everyday... i feel like i have cheated on her.

as for vapor lock.... the problem has gotten worse. acting like its out of fuel all the time. so for the price of the pump(couldnt pass the deal up) i figured i would go for it.
LongDuck, if you have a coolant sensor i could try or test mine(if the pump doesnt cure it)??

Feds

I was just reading something the other day about pinhole leaks in a fuel pump causing air in the lines. Can't remember the specifics, but good luck, and come back here for help

Rx-7Doctor

iTrader: (13)

What the pump does when it is failing is cavitate. Which means it starts pushing air into the system under load. The reason it would go away for alittle bit when turning the key on and off is because it would build up system pressure again.
then under demand start to cavitate. If the ccolant temp sensor was unplugged for the ecu then you would have a very big driveability problem. the only other thing that would happen with the CTS is usually cause poor mileage due to the fact when it goes bad it's usually telling the computer that it is way cold outside and to deliver more fuel. As far as the mileage goes it makes sense because it
probably has been running around a mixture of 16.0 to 17.1, lean machine.
After the fuel pump it will go back to it's nasty self,lol.

SimRX-7

well isnt that a pooper... i like my sweet mileage... maybe i should just frame the reciept from sunoco and have to seetle for nice performance :P

LongDuck

As RX7Doctor pointed out, the CTS is unlikely to be the cause, since your fuel mileage was so 'good' before.

When you get the new pump in, let me know. I think that's going to fix the problem for you, though. I'd be very surprised if that didn't do it.

Take care,

SimRX-7

if it doesnt...well i may just be considering a carb!!!

i would have to kick my own *** for putting in a aluminum 302...but the thought does cross my mind.

Feds

When going carb, ship all unused FI parts to Feds' FI Farm for proper, environmentally friendly disposal. I'll even waive the usual fee

LongDuck

If you put a piston engine in there, I'm not helping you anymore!

SimRX-7

LOL...
like i said..i would have to kick my own ***!!!
not to mention allow you to run over my hands with your RX-7 as homage to what should have been.

i love the look, sound and feel of a rotary...no piston engine will find it's way into my car...
wait i lied, i have radio control cars that have a piston engine in them.

Kentetsu

LOL, put a piston engine in there and you might have to stand in line to kick your own ***!

SimRX-7

FUEL PUMP ARIVED TODAY!!!
picked it up from the mailbox at 1145am...by 1245pm i was driving down I-17 on my way to a **** test for work.

we still have 5th,6th ports to repair....but...
THANK YOU ALL FOR YOUR HELP!!!
-Longduck... we will be in touch i am sure!
-Rx7doctor... i am learning...give me time

and i would like to thank Midwest 7's for the actual (used) oem fuel pump!!!
i got a great deal from him and am very appreciative!

LongDuck

So, did that fix the problem? Did you get it installed in that short period of time?

On the '6'-port repair job, start up a new thread, and I can walk you through it (with some pictures, as well). HTH,

Rx-7Doctor

iTrader: (13)

Glad your back on the road. rx7doctor

SimRX-7

yeah actually it only took about 20-30 minutes. and i will definately be starting up a thread this week... well maybe i should order gaskets first...just in case!!!

and although i am back on the road...i am sure there is something else that is close to critical... like the various oil leaks(oil pan, filter tower and coolant hose!)

viper1_20012004

oh man thats the same prob i'm having except mine is carberated and a new pump did nothing

SimRX-7

double check the fuel filter, blow out all lines. i will think further but start there.

SimRX-7

so i had a small relapse yesterday. through all of this i have not had decent fuel tank pressure(when you release the cap...no hiss.
today i tested the theory...
blew air into tank using charcol can hose. capped and took off fuel cap...nice hiss!!!(more like a woosh!!!)
then tested to the block.
after about 20 minutes i took the charcol can off and tested... no air out little hose.
covered relief on bottom with hand and retried.... blew my hand off bottom. so i need a charcol can!!!

also as a side note...longduck, you think my back-fire/popping would be reduced by removing the air pump? dealer said the anti-backfire valve is bad(think he called it an air cut.) so maybe as a test...remove the pump and cap of intake to block?

LongDuck

Well, if you go down that road, you're preventing any fresh-air from getting to your cats, so emissions will go way up.

Remember that the front eccentric shaft pulley (the timing pulley) is 'balanced' in that each belt pulls on it in a counter-balancing fashion. If you remove one belt, you're putting strain on the eccentric shaft to some degree. This causes the bearings to wear unevenly. This is a very slight effect, but one of the design considerations that Mazda had when deciding where to put components on the engine.

As far as the AP being necessary - if your air control valve is bad anyway, it probably won't make any difference. That AP pressure is going somewhere - I'm curious where... Probably making it past your ACV and directly into the exhaust ports, all the time. This air injection should only be happening on deceleration, IIRC.

SimRX-7

well i removed the airpump. no more "pop-pop" as for belts and pulleys... only alt is left.

i also cant get the damn thing to idle when warmed up now. most likely a vacumn leak. or the bac needs help.
either way i should get or make block off plate for acv.

off to work...fun fun fun