Fuel Shutoff Solenoid ( last item before IP repalcement) )

[TTM]

Hey guys, I have been reading quite a bit about this part. I read in some previous threads and another fellow was having some problems like mine. What my problem is bucking, shatter at exactly at 1500 to 1800 RMP under load, up hills, when I rev in up in neutral the problem is ONLY 1500-1800 RPM's and no other problems exist. In reading Robyn and others have pointed the finger at the FSS. The truck has is running very good, batteries and cables good, new D-Tec FSD remote mount, new OPS switch( thanks to John C for install tips) so ya. I have a code coming up for awhile at it was pulse width error to short. I put in the new parts ( hoping the problems would go away and has not and the code stayed. So I'm going to get the code read today.

I haven't been adding fuel condtioner for awhile and added a heathy dose today. SO the conditoner might help but I thought I would ask about the FSS to rule one more thing out. I just called about a new pump 1000 installed......BTW I had my IP changed under the recall in 2001. So only 10 yrs old.

So is the code for a FSS is 1219?
Where is FFS and how can I change it?.

Robyn, you have talked about this the most in my reading but if I missed a install segment sorry.

Thanks.

[DmaxMaverick]

The fuel solenoid that can cause your problem is internal, and can cause a pulse width error code. The ESS (engine stop solenoid) is the cylinder sticking out the top of the pump, with the wire connecting to it. "FSS" is a bad acronym, because it can create confusion. ESS is correct.

If you see pulse width error code(s), and the rest of your fuel and electrical systems are otherwise healthy (and you are using pump station #2 fuel), it's probably time for a new injection pump. 10 years use on your current pump isn't much to balk at. I know we would all like more, but that isn't bad. Also, a DIY replacement isn't bad. If you can change a light bulb (incandescent), you can probably do a pump with a little advice. Time consuming, but an easy job (easily done in a weekend, the first time). Although, $1,000 installed isn't a bad price.

Any codes you get should be 2 digit, being a 94 model. The 1996 and later codes will be 5 digits, one letter and 4 numbers (although many folks omit the letter, which is OK). You can read the DTC codes in your 1994 PCM with a paper clip and the key. A code "12" means the PCM is responding in diagnostic mode, and there are no DTC's (Diagnostic Trouble Codes).

[Robyn]

Not likely to be the FSS, they either work or they don't.

How old is the PMD ?? a PMD that's failing can set a pulse width error code.

I would try a fresh PMD and if this does not fix it, then its probably the IP

It could however be the filter harness on the IP (Plugs into the top at the rear and has a little black box in the harness) These can cause "Bucking" and stumbling.

Another test is to install a length of clear plastic tubing in the fuel return line from the top of the IP.

Run the engine and allow the line to fill with fuel. You should not see any bubbles. If you see a stream of small bubbles, this can cause bucking and other issues.

Missy

[TTM]

Thanks for getting back to me guys....Well I had a little time after work so I popped down to the dealership to have my SES light read just to make sure that it is the pump and they got no codes..... so I said WHAT? Got a bit pissy and got the guy to show me that there was nothing on the scanner...I know the guys at the dealership quite well and they are good guys but????? It lights up on the dash!!!! he said that the PCM will re-set itself after so many key strokes....the light came on on the way home....

Anyway, Missy the PMD is 2 months old, remote mount D-tech all the nine yards...I'm going to try what you recommend tomorrow and see how that goes and if that fails.....I took five stitches to my thumb from doing my glow plugs( the sharp piece (heat shield??) covering the back passenger side so Dmax if you say that a IP can be done in a weekend what the heck.....could make the glow plugs look like a piece of cake...I will see what I have for time I might get it done..

The truck is running fine but I think the IP needs a change. So if I attempt the IP I expect this keyboard to be real greasy and I'll be buggin the hell out of you guys.....

Thanks Again.....

[Robyn]

OMG :eek:

5 stitches is a real downer for sure.

Now, I know this is a tad late, but the glow plugs are a piece of cake, and yessssss there is a secret to doing them.

Jack up the right front, block the thing and remove the tire/wheel.

Remove the little rubber flap that covers the inner fender access hole.

The glow plugs for 3 cylinders are all easily accessable at this point.

The very back one can be reached from under the truck from the back of the engine by reaching up past the down pipe.

Sorry you got all cut up.

Another secret. Remove the nuts holding the plug shields and slide the shield down the wire to gain access to the wire connector, remove then get that stuff out of the way. Now you can get right at the glow plug without having to fight it (Front ones with shields)

Install the plugs, then slide the shield back down the wire, install the connector on the plug, slide the shield back into place and reinstall the nuts.

This same access trick allows easy removal of the starter eletrical connectors and the front "Tail hook" bolt from the starter.

Do not remove the bolt from the block, just loosen it a little, then remove the nut from the stud and swing the little bracket out of the way. :)

Hope this is useful sometime.

Transient codes that come and go can be anoying and may not set a "hard code" and record in the ECM.

OBD2 systems (96 and later) are far better about daignostics)

What you need to do is get the guys at the stealer to hook the Tech tool up and drive it while watching real time data.

This will tell the story on that transient code. Very likely that the internal
"fuel solenoid" is taking a leave.

When the response time is off, it sets the code. The computer is supposed to recieve a feedback signal from the fuel solenoid and it expects it in a timely manner. When the response is too long or too short as compared to what the ECM wants to see, the code will be activated.

A PMD can cause this, even a brand new PMD can do it ?????
Before a sprung for the IP I would try swapping in a Known good PMD, even a used stock one will work to test the thing.

I have not seen any failures of the DTECH myself. Heard of a few though.

This does sound like a "sticky" fuel solenoid.

One thing for sure, these pumps do not like dirty fuel. A 2 micron filter IMHO is a must have. The stock filter is little more than a clod sifter at about 5-7 microns

If the Fuel solenoids armature gets roughed up/galled some, it then can get sticky and bind. This causes the stumbles and other issues (codes)

Missy

[TTM]

Thanks Missy for the info on the glow plugs that will come be useful next time, But while I got you here, how or what is the best way to R and R the FFS or ESS? If you could, describe the R and R that would be great.

[DmaxMaverick]

Thanks Missy for the info on the glow plugs that will come be useful next time, But while I got you here, how or what is the best way to R and R the FFS or ESS? If you could, describe the R and R that would be great.

The ESS is simple. It's external. Don't complicate it and it's a piece of cake.

The FS, on the other hand, not so. It's the "fuel metering servo" (inside the injection pump), and rarely is a replacement successful. Pump disassembly is required, and not for the faint of heart. Once they begin to fail, pump replacement is usually the only remedy. Some have found success replacing them, but I consider them the exception, and not the rule, and lucky.

As I said above, you don't need a dealer to read your PCM codes. All you need is a paper clip or similar device (jumper 2 contacts in the ALDL), turn the key to "RUN" (no start), and count the SES lamp flashes. That's it.

If you see the SES lamp, you can pull the code immediately. Even transient codes. When it lights up, pull over, shut off, install the paper clip, turn on the key and count the flashes. If you restart after getting a transient code, and the condition that set the code is no longer there, it will turn off the SES and the code may no longer be present. Some codes remain in memory longer than others, depending on the code class.

If you need a real time code read (while the engine is running/driving), you'll need a code reader (inexpensive and reusable), or a dealer (not inexpensive). If you intend to have pre-1996 for a while, I suggest getting a reader capable of reading both OBD-I and OBD-II vehicles. This will allow you to read codes at will, and reset them with the touch of a button (rather than using the hand/foot/finger coordination method). Full function scanners (Tech-xx tools, and the like) are expensive, but make many things doable for a DIY'er. There are also PC interface apps/hardware available.