I was thinking no because I wanted to see if it was something else first but the more i got to thinking I really should since the fuel pump/filter are one and I don't even know when/if the fuel filter was ever changed.

Edit: Zman you always seem to help me in any thread I post.. I'ma have to send you some $ via paypal or something soon enough for all the damn help man.

 

I would advise against any cleaning of the PCM due to ESD damage. You will need a grounding strap for one to prevent static discharge into the pins of the PCM at which point, you will inadvertently fry the voltage sensitive components inside thus rendering the PCM dead or, intermittent at best.

The other factor is what are you going to clean it with. It usually is best done by someone who knows what they are doing to avoid damaging it.

That's my advice.

CM

 

+1, that's why I asked about the fuel pump. Do the pressure test as stated earlier. No pressure, check fuel pump relay and wires. If it's none of those, the pump is bad. 99.9 percent of the time it's the pump. And get a Haynes manual at least, if you plan on doing it yourself.

 

LOL, That's what we are all here for, FREE advice.

 

don't send him any damn money !!! if you take his advice you'll need it ALL for truck parts. lol.

 

Well , here's my advice (quoted)

They pack the connector with silicone dielectric grease at the factory. I use the stuff all the time. It's good but after many years, the gel thickens so that it becomes a problem.

For the PCM connector, I used a spray can of electronics cleaner that is safe for plastic. Auto stores around here have CRC Industries QD Contact Cleaner http://www.crcindustries.com/ei/content/prod_detail.aspx?PN=02130&S=Y so that's what I used. Anything similar would be good but be sure the can states that it is: (1) Safe for plastic, and (2) Leaves no residue. We've got to be careful with it. It's extremely flammable and it pools in places you wouldn't expect. Before you reconnect and energize, you've got to blow the harness connector with an air gun to be sure to flush that flammable stuff out of invisible crevices. If you don't, it could burn from the slightest spark.

I needed something abrasive to polish the inside diameter of the female terminals in that harness connector. I had to pick something that would leave absolutely no fibers behind and leave no abrasive particles behind.

I bought a long bristled brush with plastic bristles like the scrub brushes sold at hardware stores. I cut bristles from the brush. Exactly 6 of the bristles from the brush I used fit snugly into the bore of a single metal female terminal in a cavity of the harness connector. I used medical forceps to hold the bunch of 6 bristles together. I inserted the bunch of 6 bristles into a cavity and then I'd spritz some of the cleaner into the hole. Then, using the forceps, I worked the set of 6 bristles up and down about 10 times.

I did this about 56 times. About 4 of the cavities are empty. They don't have a connector terminal in them. So, I did each of the 56 female terminals in this way. It took me almost 2 hours but when I was done, each bore of the 56 or so female terminals was clean, bright, and shiny. .

Then, I used an air blow gun to send streams of air down each bore in the cavity. This blew out some remaining chunks of old silicone and it also made sure that any residual cleaner solution was evaporated away. That stuff is seriously flammable.

To clean the male pins of the PCM, I used the same electronic cleaning spray with an acid brush like you'd use for applying flux to a solder joint. I'd spray the brush and then polish the pins.

It was a pain but it was worth it because I was just about ready to plunk down $275 for a new computer. As it turned out, that would have been a waste of good money. All I really needed was clean contacts in the wiring harness.

I think it's important to pick something to clean each bore that won't expand the bore of the terminal. It needs to be tight when we plug it back together. I think that a bunch of plastic bristles were perfect because they are compressible and flexible. They scrubbed the inside bore of each connector without distorting the connector's shape.

I never used the same set of 6 bristles on more than one cavity because each time I removed a set of bristles from the bore, I could see with a ***ler's loupe (magnifying eyepiece) that I was removing extremely tiny congealed globs of silicone dielectric compound. I didn't want to contaminate the next bore with gunk from the previous bore.

I guess you could first try just spraying the cleaner into the bores and then blow them out with air. If it works, then you don't have to scrub each bore of the connector. In my case, however, I've been struggling for months with all the stalling, sputtering, and trouble codes and I wanted to make sure that I was eliminating that connector as a source of the problems. I wanted to add some physical abrasion to the cleaning procedure.

So, with that dirty connector, my Idle Air Controller (IAC) wasn't functioning much of the time and that's why my engine speed was hunting between 0 and 450. Also, the sputtering must have been my fuel pump cutting out every 1/2 second or so. The O2 sensor code was setting because sometimes there was no signal getting back to the computer.

Everything is controlled by the computer. In that PCM harness connector, 4 of the cavities are just for the IAC. 8 of the cavities are for the 8 injectors. It goes on and on. Everything about the engine feeds back to the computer. Any dirty contact in the PCM harness connector can cause a total failure or an intermittent failure of any one component or it can cause several components to act up.

If you discharge the PCM properly , and have power (battery)disco'd when plugging & unplugging in the connection , you'll be fine

 

check the pressure at the rail at prime, you should be gettin 46-58 psi depending on your year.
with the engine running you should hold steady at this number wtih a 1+- percent drop/increase.
if the number is low, before replacing the pump do a resistance check on the circuit and make sure you dont have high resistance in the circuit.
if everything is good, replace the pump.

you would be able to see/smell fuel if it was leaking, plus with the volume the pump can move it would be everywhere.

 

on the quote above, it is very dangerous to clean your terminals of the PCM. they are very sensitive and can actually seize together if they are damaged in any way. They are coated with gold to allow expansion during heating and cooling. if they are damaged the connections will not be true.

 

To the original poster -that is correct. The post about cleaning them using that method is crude and should never be performed under any circumstance and I will tell you why.

First of all, let's get some background here by saying that I work as an engineer with electronics of all kinds- from aerospace and defense electronics to consumer navigation systems to auto applications. I have worked on wire harnesses to high tech semiconductor materials so, I am very familiar with electronics of all forms as well as the manufacture of electronics and microelectronics. I will explain why not to clean your PCM unless you know what your doing and have the proper means to do so.

Even though the poster remedied his issues (for now) there's some issues that may crop up later due to that method of cleaning which will be covered as we go along. I feel this is important that you are familiar with this topic and why I stress not to clean it yourself.

First issue is ESD. IF you are not familiar with what that is it's Electrostatic Discharge and, ANY motion creating friction leads to voltage build up. Sanding, brushing etc and any motion of the human body for that matter generates huge voltage potentials as well as air being blown across the pins that has potential to wipe out voltage sensitive components. The air gun must be of an ionized type and not just a hair dryer, heat gun or any off the shelf air duster using plastic nozzles. They make special air guns and cans for this purpose.

Failure modes are either catastrophic or latent meaning, it's either dead now or, eventually, down the road, it will die. Then we have the intermittent failure which are the worst kinds of failures. This is due to ESD damage and. some people are not aware of this and tend to blow it off and think "hey, it's no big deal and, you'll be ok if you do this"- that's false. One assumes all is ok because right now, "hey, it's working so, it must be no big deal". I see this every day, year after year and it's a huge problem if it's not addressed.

Now we will go into abrasive cleaning of contact pins.

Cleaning of contact pins with an abrasive should never be used- especially on tight-fit, low-tolerance interface pin contacts. Also, none of the PCMs that I have worked on have dielectric grease as it is conductive and, the last thing you want on a MULTI-PIN connector is a conductive medium that SHORTS out between pins. That's most likely the root cause of that posters issues, not dirty contacts. Dielectric grease is usually used on isolated connectors like spark plugs, not on MP connectors.

After using any abrasive cleaning, the diameter of male pins and female pin contact has been reduced thus opening up the tolerances from the OEM design. This can lead to intermittent contact issues due to thermal changes in the environment. This can be seen in thermal cycling chambers while under test in operational test modes.

On each of those pins there's a plating to resist corrosion. If the plating is worn through or even worn thin enough, there's potential for another issue and that is, the base metal will either be exposed or, it will start to bleed through due to removal by abrasives. This can lead to high contact resistance and intermittent connections as well as possible short conditions (under the right conditions) to neighboring pins at the connector interface due to dendrites and other metallurgy related growth. Usually, it's a Tin plating but, not always, as some OEM designs use silver or gold platings.

The proper way to clean pins is with chemical treatment and, the right chemical for the application. A can that says "safe for plastics" may damage something else. What kinds of plastic is the chemical safe on? What is the type of chemicals does the cleaner contain is also another question that one needs to ask his or herself before using it. What other materials are in the connector that may be damaged? Is there rubbers, polymers, chemical sensitive o-ring seals etc? All of that needs to be factored in before choosing a cleaning medium in order to prevent damage.

Some chemicals will actually etch the plating and, if you already sanded them, well, now your losing more of the plating plus etching the base metal which may etch at a faster rate as it's usually softer than the plating material thus compounding the problem. Again, these need to be completely evaporated as it will cause a short in the connector.

Now, using a brush on multi pin connectors can also lead to another issue- FOD. Foreign Object Debris left after the cleaning operation. They make special tools for this that fit over the contacts and into the socket if needed.

Again, there's not supposed to be anything inside the sockets and, normally, all that needs to be done is use the correct chemical and mate and unmate the connector several times is all it takes to clean them due to the contact pins rubbing inside the socket walls. They clean each other so-to-speak and, this is the preferred method of cleaning under normal conditions. If there's contamination, then that needs to be addressed by using another method.

No need for any abrasives unless- the pins are corroded and / or have a medium on the surface that can not be blown off such as dielectric grease. Same with the sockets.

 

Besides, the OP says he can hear the motor running (which doesn't mean it's pumping fuel).So it's getting power. If there is no leak, it's got to be the pump or screen or filter. In any of those cases you replace the whole thing anyway. Plus it's a 98, so .....