fuel pressure sender location

I have a 94 Topaz and suspect I have a failing fuel pump. The two symptoms are: (1) the car runs well most of the time, but at high rpms I occasionally get pinging, (2) when idling in drive, the engine seems to vibrate more than it should. About the vibrating, if I put it in neutral, rpms go to around 850 rpms, and it's very quiet and the vibration goes away, but in drive it drops to 700-750rpm and vibrates (I can feel it through the steering wheel). At first I suspected the pinging was due to carbon deposits inside the engine, so I put in a couple bottles of higher quality super concentrated fuel injector cleaner at two different fill ups, this seemed to smooth it out somewhat, so I figured it was getting a routine injector cleaning which helped anyways, along with removing carbon as the bottle claims. The more I read on the internet, if the fuel pump is not putting enough pressure into the system, this will cause a lean mixture and maybe pinging. I suspect this is what is happening at higher rpms. At lower rpms, a lean mixture can make it run rough (the vibration). I tested system voltage, at idle in park is 14.53 V, in drive the same, with headlights 14.44 V, with A/C 13.12 V, so I imagine the fuel pump is also getting this voltage, and at this point I am ruling out insufficient sparking voltage (coil problem). I "tested" the fuel pressure regulator as other people suggest (remove vacuum hose to see if there's fuel coming into the intake manifold and there's no fuel coming through) so I'm assuming that it is working as well.

Before going out and buying the pump, I'd rather test the fuel pressure in different driving conditions (idling and highway speed), and I've seen testing kits that have a hose and mechanical gauge, but I can't use this on the highway. So my question is, if I'm using the right fitting to ensure a tight seal, is there a problem with attaching the fuel pressure sender on the fuel rail at the "Pressure relief valve" according to Haynes manual (Schrader valve)? It seems a logical place to put it since it would be measuring the pressure the injectors are seeing, and wiring would be simple right through to a gauge inside. I've seen others put the pressure sender BEFORE the fuel pressure regulator, but as I understand it the pressure may fluctuate while driving, which is why the fuel pressure regulator is there, to keep a consistent pressure for the injectors, and I really want to see what pressure the injectors are getting.

I will put a new fuel filter and PCV valve in, they are about 20000 miles old, although I don't suspect the fuel filter as being a problem as I always but quality gas (Shell or 76) and 89 octane. Other information on the car: just passed 100000 miles, always routine oil changes, Bosch Platinum 4+ spark plugs (ran a lot better), K&N air filter (WOW! LOTS MORE POWER AND MILEAGE! Everyone ought to have one), new cap and rotor, plug wires 20000 miles old, recent water injection for removing carbon deposits (also helped, seems there's less pinging overall so I'm happy, lots of dark grey steam that stank of carbon came out while doing this). Last year took a road trip on old, bad cap and rotor, still got 30mpg on what Ford says should get 27mpg, I attribute this to the K&N and the Bosch plugs. Can't wait to test it again now with the new cap and rotor. Recently checked the plugs and they look fine, a light grey and no other deterioration, two electrodes look like they spark more often than the other side or one side is exposed to a hotter part of the chamber, which is interesting

Reply to
jhavelka
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Sounds like your car is running pretty good. I remember the water idea from when I was a kid and I think it makes sense but have not tried it since 1978... Would be interesting to hear from someone as to whether this really helps or not. I did try it making my own homemade contraption but I could not tell whether it helped or not as I was a young kid and didn't like the idea of emmision controls so I started dismantling them on the Oldsmobile Starfire I had at the time. If I could take it off the car at the time I did and that included the vacume advance for the distributor! Funny... But not so funny because that car ran terrible and it was all my fault.. Yes I left the vacume advance disconnected and sold the car that way... Someone ended up getting a great car after the mech put the vacume hose back on the distribtor! Well enough said there.... Dummy in my young age...

But this does bring me to the idea that this could be and EGR problem. A carboned up port for the EGR could cause the combustion to be to hot... Worth looking at anyways.

I also have a K&N but I'm not sure that it should provide "LOTS" more. It is better yes but I think that changing your dirty airfilter probably had more to do with the "LOTS" improvement...

Gerald

Reply to
gerald2003r

Just another thought here... Thinking the fuel pump would die or leak before they give out less pressure. Thinking even if the fuel pump was weak the regulator would make up for the lost pressure... Just an idea, I could be terribly wrong... I had one fail before but it was total failure, 6000 STE...

Gerald

Reply to
gerald2003r

I forgot to mention, yes I checked the EGR for suction and movement of the pintle valve. The diaphragm holds suction. To test the EGR with the engine running (idling), I removed the cap of the EVR and momentarily held the bleed hole, the engine nearly stalled, so I think the EGR is working as it let exhaust gases pass through.

I also checked the air bypass solenoid (idle air control). Both the air bypass solenoid and the EGR were remarkably clean, very little carbon. Although I checked these components for obvious damage, the real test would be to see what the operating voltages are on the IAC and EVR as the engine is running, or while driving down the road. I may not have the tools to do this.

Reply to
jhavelka

Having recently taken a hydraulics class and studied pumps has given me a lot of help visualizing automotive components. I think if the fuel pump starts to fail, either the pump blades are physically worn and cannot move fluid, or more likely the bearings are worn and the pump blades are spinning a lot slower, resulting in low flow rate and lower pressure (or thirdly electrical connections are wearing thin). Since the car mostly runs well, I am thinking the pump is just starting to go downhill (just beginning to shown signs of wearing out).

Reply to
jhavelka

If you really want to get rid of your problem:

  1. Get rid of the Bosch plugs and use the original (copper?) Motorcraft plugs. Bosch plugs seem to cause problems on most Ford vehicles.

2: Ditch the overhyped K&N filter and use the correct filter for the can. Then clean the oil deposits off of the MAF sensor from the overlubed K$N filter. This will probably stop the pinging.

3: Replace the worn out motor mounts, all 3 of them. These motors don't really idle smoothly and when the mounts get old they transmit vibrations through the body.

If your fuel pressure was low you would have other driveability concerns. These pumps generally fail completely. Low pressure, while not unheard of, is very rare. If you really want to check it connect a gauge with a ~3' long hose to the schrader valve and tape the gauge to the outside of the windshield. It should read between

30-40 PSI depending on load with the average reading about 35-38 PSI.
Reply to
Tom Adkins

I agree on all counts with the exception of the fuel pressure. The 2.3 should have between 45 and 60 PSI with the engine running. Bob

Reply to
Bob

I checked the MAF about a week ago when checking the IAC. The inside of the intake hoses were spotless, but I did shoot a little canned air (for cleaning dust off electronics) into the MAF. As I understand, the MAF is just a Pitot tube with a pressure transducer at the end. I can replace the air filter with a paper filter. If I don't feel any oil or even a film on the inside of the hoses or any parts in the intake, how should I clean the MAF? I wouldn't think spraying carb cleaner inside the MAF would be a good idea, if there's delicate electronics.

Reply to
jhavelka

Remove the 2 tamper resistant torx screws and pull the sensor out of the housing. Clean it with alcohol and a q-tip watching for stray fibers. It's somewhat fragile but you won't hurt it if you handle it gently and don't bang it on anything. You won't usually be able to see or feel the oil film in the intake, but trust me, it's there. K&N filters on MAF equipped engines cause lots of problems. Also, the only improvement over a paper filter happens at over ~5500RPM if at all. Any performance or fuel mileage gains are psychological, like a good wash, wax and detailing seems to make the car run better. That motor can't possibly draw in enough air for a paper filter to be restrictive.

Reply to
Tom Adkins

A note on the pinging: it has been pinging for probably 40-50k miles, and like the saying goes, "older cars may need a higher grade of gas to help stop pinging." So switching to 89 octane from 87 helped most of the time. It used to ping going up hills on the freeway, so when I heard it ping, I would just lay off the gas and get into the truck lane while everyone else passed me up in their fancy new cars. Lately as I was trying to find out more about how to treat pinging, I came across a google group post that said injecting water into the air intake (they were talking carbs on old cars) will flash to steam and helps clean away carbon deposits. Since water is an end product of combustion, I figured it could not do any damage to the engine to try this. So I used a spray bottle with a fine mist and slowly sprayed it into the air intake while in park. To be honest, now the pinging is 80-90% gone, I can hit the gas going uphill on the freeway right in the rpm range (2900-3300rpm, it is a 3speed auto) that would invoke massive pinging, and it's pretty much gone. Nothing else has changed, I still buy 89 octane gas, no other changes. So it made me think: is this engine particularly prone to carbon deposits? And if so, how to clean it? The water seems to have worked well, but I will still clean the MAF according to the post.

Reply to
jhavelka

Sorry I don't agree with the Bosch plugs idea. Bosch makes most of the the injectors used and I think they have a great idea with the +4. I have them and they work great. Copper is also a good idea but it doesn't have the electrical qualities of Platium.

Not knowing anything about spark plugs... I have to ask... Do I want only one ground for the electrode to contact or 4? Do I want the spark to come from the side of come from the center? What do the the racing people choose? The Splitfire people were the the people to bring out a plug that was not side fired. What is it? Does it matter where it comes from "The spark from the spark plug" ? Is it intensity of the spark"Hot spark vs Cooler"? Is the Bosch +4 considered a hot spark or a cool and can you please explain why. Is a Copper plug hot or cool and can you explain why? I understand that the distance that the length of the plug has something to do with hot or cold... What I'm looking for here is whether the spark should come from a quad ground... Spark directly centered of from the side as in the copper plug.

Motor mounts... It will depend on whether you have rubber or hyrdaulic mounts. I would not worry about them unless you are getting a BANG from either rubber gone and it is now hitting the steel frame of the mount or a BANG from the hydraulics failing as mine did.

K&N... I have one but I cannot say for sure whether is helps or not. Sure looks a hell of allot better than the stock "Motorcraft" filter... Yes more money... But...

Gerald

Reply to
gerald2003r

Cleaning the Map sensor maybe clostly... You may endup buying another... When was the last time you changed the O2 sensor? (Always disconnet the battery) (Kill the computer memory at the same time!)

Gerald

Reply to
gerald2003r

Still worth pulling the EGR to remove any carbon? No? Worth a look... Costs a gasket... :)

Reply to
gerald2003r

How do you figure cleaning the MAF would be costly? Cleaning is nearly free and if it is contaminated replacement is the only other option at about $100. The sensor is not nearly as fragile as many people think, no more so than any other engine sensor.

Reply to
Tom Adkins

What kind of car do you have them in? It's widely known that Bosch Platinum plugs can cause driveability problems in many Ford products and really shouldn't be used. I'll bet you didn't know that Bosch glow plugs are generally considered to be junk by most Ford Diesel owners, did you? They just don't last. Yes, their injectors have proven themselves. BTW, the use of platinum in the electrodes has nothing to do with the electrical properties. It just makes the electrodes last longer, they don't conduct any better.

If you don't know anything about spark plugs then how do you know Bosch has a good idea with the +4? The spark will only jump from and to 1 electrode, the one that offers the least resistance at that moment. Hot and cold has nothing to do with the spark at all. It deals with the temperature of the tip. The "Splitfire" design was proven long ago to be nothing but a sales gimmick, as I feel the +4 is also.

The rubber on non hydraulic motor mounts gets hard and flattened and doesn't cushion well. The hydraulic ones can also leak out and transmit vibrations to the body. The Topaz has at least 1 hydraulic mount and they fail often. The 2.3 engine produces a lot of vibration and has to be well cushioned.

How does it "look" better? What possible visual indicator can tell you which is better? It looks "different", does that equate to "better"? The only advantage to the K&N filter is in high performance applications at high RPMs. There have been tests that show the K&N actually doesn't filter quite as good as a quality paper filter. The difference is minimal, but it's there.

Reply to
Tom Adkins

30 MPG because of those?

Bullshit! Especially the Bosch plugs.. almost everyone on here has had personal experience with Bosch in Fords.

If it ran better with them, it would run just as good or better with Motorcraft.

And my kid's Topaz went to over 32 mpg when the EGR system screwed up.

Reply to
Backyard Mechanic

Hey BY, was that car a 5 speed. I've never been able to do any better than ~25 with an automatic Tempo\Topaz. The one stick that I had was a 3.0 so I can't really compare them.(I did have an 84 stick but it had a carb) Funny thing, when I replaced the burnt PFE snsor on the 3.0 the fuel mileage actually went down!

Reply to
Tom Adkins

5 speed 2.3 He had the same result as you.

I had to nag him to fix it because of the better mileage... shouldnt have bothered, the clutch went out and he had it towed away, mainly becuase he was too bored with the car to replace the clutch

Reply to
Backyard Mechanic

If you don't know anything about spark plugs then how do you know Bosch has a good idea with the +4? The spark will only jump from and to 1 electrode, the one that offers the least resistance at that moment. Hot and cold has nothing to do with the spark at all. It deals with the temperature of the tip. The "Splitfire" design was proven long ago to be nothing but a sales gimmick, as I feel the +4 is also.

To bring people like you out to talk about it and to educate. But you still have not told us about side fire as apposed to the +4 center fire... ? Well if what I see in the design hold true the resistance should be equal. 100% ground, yes if you would like to get into metalurgy I suppose they might not be equal, but I don't think Bosch is putting out an inferrer (Spelling) product. Now that I know you are an educator please tell me more about spark plugs. Why would you want a "Hot plug" Why would you want a "Cold" plug? What would be good or bad about a "Side" firing plug as apposed the the +4 that seems to be a "center" firing plug? All I can say about splitfire is that I did run it in my Ford Taurus 1994, the same one I have today and it went

100,000 without any problems. I removed the at that point and they looked normal. Are you going to tell me platinum does not conduct electricity better then copper????

Yes the K&N DOES look visually better. You can just about see through it. Over time it will fail, I don't believe in the recharge kits at all. I think that is BS... Yes it is more expensive but probably worth it. Try running dust through your paper vacume cleaner... Mine tells me when it is full of dust... It doesn't take long... But what this should tell us more then what filter is better or not is to change it more often. Every 5000 miles if you would like to use your favorite paper filter. Every 10 to 15 thousand miles if you would like to use the more Expensive K$N filter.

No I think Germany makes a high quality product with their cars, injectors and plugs. I'm not a fan of Germany in the first place going back to the war I was not a part of... But I do believe they make good products.

Gerald

Reply to
gerald2003r

I'm not an educator, just a guy that spent 23 years as an automotive technician. I've seen the gimmicks come and go. All the spark plug does, basically, is carry the spark from the outside of the engine to the cylinder. Side fire, center fire, it doesn't matter. Copper, platinum, steel electrodes (anode and cathode), it doesn't matter. The spark will only jump from 1 anode to one cathode. The other cathodes do nothing. The spark may jump to different cathodes each time but will only jump to 1 each time it arcs. Yes, platinum conducts better than copper but that is not why it's used in spark plugs. It is used to extend electrode life, as it won't erode as fast as copper. The ability to conduct better doesn't come into play in this application due to the small amount of platinum used.

K&N filters have been proven to filter LESS efficiently than paper filters. Not by enough to really matter. The job of the filter is to keep dust out of the engine, period. The purported advantage to K$N filters is their ability to flow more air. They have the advantage at high engine RPMs with high airflow. This is true, but the engine in a passenger car will never flow enough air to see an advantage from the K&N. The oil in the filter element also has a propensity to foul the MAF sensor on cars so equipped. On passenger cars, you gain nothing from the K&N filter and possibly cause problems.

I never claimed that Bosch makes inferior products. They make products that don't perform well in certain applications. Bosch plugs cause problems in many ford vehicles. I've seen it many times, as have many others. By the way, Bosch glow plugs are made in Japan. Says so right on the plug body.

Do a little research on Bosch spark plugs in Ford vehicles and K&N filters in the real world. Let me know what you find out.

Reply to
Tom Adkins

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