then move on to the black/white wire to the top of the tank, stab it and measure the voltage with the engine running, if it is close to battery voltage but a few volts shy crimp the hose after the pressure gauge and do a peak pressure test on the pump with the engine off. if it is much below the 90PSI mentioned then replace your pump.

 

Hi RotaryEvolution. Given that I did already check the fuel sock and it is pristine like new and the fuel filter was replaced last month when this all started what should I do? Shall I check the voltage as you indicated? Also, I remember looking in the tank and it was very clean and I remember seeing shining aluminum color with clear fuel on top of it that I could see through! I do not remember the fuel pump having any corrosion at all on it per say.

 

Got that message RotaryEvolution! Will do so and revert back to you in the next few days!

 

Hi RotaryEvolution. I was too anxious and had to finish the tests! Went to the white/black wire on the fuel pump and with at running and tester grounded it gave me the exact same voltage of the battery which is 12.78 volts. On it went and let the car stall out. I jumpered the gas pressure connector on the passenger side fender and turned the key to ON and got the same 29-30 psi as yesterday. Then I clamped off that return hose to the fire wall and it went up to 60 psi only. I can still do a test and crimp it right after the pressure gauge. I will do that now and see what it gives. Be back to yo in a moment.

 

Hi again RotaryEvolution. I clamped the hose right after the gauge and still for only 60 psi just like when I clamped the return hose to the firewall. So, in your expert opinion, do you think these values are what has caused all these issues OR are you still suspecting fuel injector issues with a car with only 33k on it? Are there other symptoms here that may lead you to believe it is BOTH problems? What are the chances 2 things like this happen at once? Can fuel injectors that are in need of cleaning cause a fuel pump to WEAKEN? Sounds as not to me logically. Ok, I will await your diagnosis RX7 Dr.

 

the fuel pump is definitely weak and is part of the problem but it doesn't seem to be the main cause of the running issue.

pick up a can of carburetor cleaner from an auto parts store and try to get the car running again and prop up the throttle so it idles without stalling, keep a fire extinguisher handy but on a rather cold engine there shouldn't be too much risk of igniting the carb cleaner in the engine bay.

spray the carb cleaner around the top of the engine and see if the idle smooths out or stumbles when spraying in any particular area. this is to check for vacuum leaks which could be causing the main problem.

 

Hi. Ok, you need to help me on the specifics of this. I have had people tell me to do this, but I never understood EXACTLY what to do. First i buy a can of carb cleaner which i can do Friday. So, I get the car running again. When you say "prop up the throttle so it idles without stalling" do you mean I should so what I have already done and put something on the accelerator to hold it to like around 1000 rpms? Now were in the engine bay am I spraying the carb cleaner? Shall I spray on hoses that have air running though them? Is that the goal here? Can you point out in some way what exactly to spray so I am not spraying everything under the hood? And, why is it that if the idle smooths out or stumbles then I found a vacuum leak? Does the liquid like go in a possible crack or hole and momentarily stop air from getting out and then the idle gets better?

 

You will spray anywhere that air can get into the intake system of the car. This includes vacuum lines, injectors (if they have bad o-rings), any where "un-metered" air can get in teh engine.

The spray is flammable. it will be like adding a small amount of gas to the engine. It will either make it run better (if it is lean), or make it run worse (if it is too much fuel). That is why it works.

Rob R.

 

pretty much, everything on top of the engine is a vacuum source to the engine and everything needs to be sprayed down to see if the idle changes at all. have an assistant hold the throttle to keep the engine at 1000RPMs or prop the throttle pedal with something to do the same, since it apparently will stall if you let off the throttle completely.

 

Thanks both of you; I appreciate that. And should I notice where and what I sprayed if and when I see a change in idle either running better OR running worse and keep tract of what exactly I was spraying that caused one or the other? And what about the engine catching fire.....that scares me...what can you tell me to make this more safe? It will be done from a cold start so that should be rather safe? How far away should the can be from the parts when I am spraying? Last questions!

 

If you didn't keep track of where you were spraying then it would be a waste of time actually. Hold the spay can within a foot of the target (6 to 10 inches at most).

 

Thanks!

 

about the biggest concern is arcing spark plug wires, you really shouldn't need to be spraying much on the driver side of the engine anyways, most leaks are under the upper intake manifold in the pocket on top of the engine or down near the lower intake manifold on the passenger side of the block. if the exhaust is cold you should have no worry of anything getting ignited, arcing plugs will ignite much easier.

to check for arcing plugs, run the engine in a very dark area and look at the driver side of the engine and follow the wires to the block and see if you are getting any spark arcs jumping around.

unfortunately this is the easiest way to check for vacuum leaks, just be weary of the aforementioned issue, the carb cleaner dries quick so even if it does ignite it will almost immediately go out if you shut off the can. i have never had it ignite while checking for leaks even on scorching hot engines in 115F ambient heat with engines fully warmed up.

 

Thanks again for the information! Very informative! I will attempt this hopefully Friday or on the weekend and get back to you! Very much appreciated!

 

Question for RotaryEvolution and Satch. I read a lot on the use of carb cleaner and finding vacuum leaks. Can you tell me if WD 40 is better or worse and why? I have a can of WD 40. If I have to go out and get carb cleaner that is not a problem, I can do it today. What are the benefits and dangers of each? Is one really better than the other. And can either warm hoses in the RX7?

 

warm=harm! sorry.

 

don't know about WD40 or how it will affect the engine when it finds vacuum leak point or it's affect in larger volumes on many different components.

the fire extinguisher is just a safety measure, i doubt you will find anyone who has ever even needed it.

 

Thanks. Here is the update. Since I found so so many people on the net in links that used either WD40 or carb cleaner, I used the WD40. I put a few more gallons of gas in the car and tried and tried to start it and it got to a point where it was cranking real slow and low. So I let it sit for a while. After an hour I went back and I just got it started BUT I HAD TO BE PUMPING THE ACCELERATOR AND HOLDING IT DOWN MIND YOU TO GET THE RPMS TO JUST SLOWLY GET UP AND ONCE I GOT IT TO 3000 RPMS I WAS ABLE TO KEEP IT GOING! That is how hard it was to even get started! NOW, I kept it there for a while and brought it down to 2000 and then 1000 and placed something on the gas to keep it at exactly 1000 rpms! Got out and sprayed carefully and consecutively each and every hose going into the engine on the passengers side and the back and front sides of the engine. NOTHING AT ALL HAPPENED! No increase or decrease in idle at all! I wiped it down and it dried and I did I again making sure I got everything and did not spray any of the drivers side because there are no hoses I feel I needed to do. Or should I have done there too? Then I let it stall as usual. I restarted it a few times but each time it needed gas all the way as the rpms just slowly crept up! I had the car running for a good 20 whole minutes in total today. I WANT YOU TO NOTE THAT JUST FROM BEHIND THE ENGINE THERE WAS A VERY LIGHT SMOKE BILLOWING UP AND IT SMELLED LIKE BURNING OIL! Whenever I have run the car that long during this issue I have been having with it over the last few months, that was a typical symptom and always happened after running the car that long and then letting it sit and cool down. I checked the oil level and it is still clean as can be and no change in oil level since I changed it and the filter a month ago! What next guys?

 

You might want to try removing the Oxygen Sensor from its nesting place by unscrewing it and this will allow exhaust to escape from the hole. If your problem is associated w/a clogged cat then the car should run better w/the extra opening. And I still think you have clogged injectors.

 

do what satch said, if no change then you will have to pull the upper intake manifold, strap the injectors to the rails and do a flow check on the injectors to see if both primaries are working.

check the grounded ring terminal to the rear rotor housing while the UIM is off, it can cause all sorts of injection issues.

 

Ok guys, remember I am a novice and no little SO where exactly on my car is the Oxygen Sensor and what does it look like and when to say "remove it" what does that entail, removing it from the car in total? If it is a clogged cat problem and this alleviates it then how is a cat unclogged? Again, remember you are talking to a novice. Thanks again.

 

The sensor looks like a tube standing upright and is screwed into the exhaust manifold. You would need a special socket to remove it found at your local auto parts store. You can hammer the converter and knock loose the blockage or bypass it w/a tube or get a new one.

 

I went into the FSM and I think I know where it is. Is there any reason to do what they say in the FSM before I remove it to see if letting exhaust out that port helps WHICH IS to disconnect the o2 sensor connector and see if the voltage is .5 to 1 volt when accelerating( I guess reving it up at rest in this case) and 0 to .5 volts when decelerating( I guess letting the rpms fall while at rest). I assume my problem as described can not be all due to a bad o2 sensor in any way correct? Just curious?

 

nope, the O2 sensor has a minimal impact in drivability. what you need to figure out is whether there is a huge restriction in the exhaust or if the engine isn't getting enough fuel. all assuming the engine internals are in fact ok, as you mentioned the compression test which should rule out the engine.

only other possibility would be a large intake restriction like a plastic bag covering the intake or massively clogged air filter.

 

Could I try starting the car without the air filter in? If I noticed a change could that be an issue? I only say that because the car has been with the hood up for the last few years except when I took it for small drives to warm it up and as you know this past winter I just neglected it too much and did not warm it up enough. Well when I went and took out the air filter for the very first time, damn chip monks hid small nuts and shells all the way up to the filter...so I obviously took it out and took all the little particles out and put it back in....nothing got past the filter of course and the filter was intact BUT a orangish color. I assume that is the color of the filter material? Chip monks also hid their damn food on top of the darn fuel pump and I cleaned those off the top of it last month!