tips for replacing OPS

[garre1tt]

Well the trouble shooting is complete. Both my 6.5s need new OPS.

I am looking for tips for accomplishing this. Are any special tools required?
Are both the 95 and 97 located in the same spot?
Alldata was not very helpful for this R&R.
Thanks
Michael D.

[Artworks]

I added ops and relay from Kennedy , found out the adapter would not work as hits the drivers cyl. head., so mounted it 'under' intake in threaded port ( with allen head plug )just forward of factory on the '95 , tricky as very little room there to work. Could saved a hour or so if done this first . Rest of install went well. So far LP is working way it should ( however noisy ???) Only special tool was oil sender socket and may have to modifiy to work under the intake area. Yes you need good light , long skinny fingers and time.

[garre1tt]

Time, Skinny fingers and socket are the three things I don't have.
I guess this is why I have not done it myself in the past.

Thanks
Michael D

[94 at Large]

As mentioned in above post the socket makes the job go much easier, about $8 at local parts store. Remove the bolts from the bracket holding the fuel filter, gently move to the side (fuel filter is hard piped but has some give) and this will allow some much needed room to get to it. Have some extensions and a swivel connection handy as that will make it easier. Mine was so tight that I had to tap with a hammer at same time. I have a 94 model so I don't know if the setup is different than yours, however, in all it took about 45 minutes to complete. The first time is hardest so the second should go much quicker.

I am also in the process of installing Kennedy's harness as I think my OPS has taken another dump on me and I just have not gotten around to hooking it up. Once that is in place then the OPS is no longer in the loop except to run the oil pressure gauge.

[Kennedy]

My best suggestion is to rid yourself of the ever failing OEM OPS setup and add my lift pump control harness. Unfortunately, I needed to change circuit board suppliers and am out of stock for a few weeks yet...

[garre1tt]

Thanks for the further comments.
I am going to give it a try.
Kennidy, I saw that you were on back order, maybe next time. That should be about a year from now at the same rate I have gone through these.

I will post when I am finished and add any thing that I learn.
Michael D

[Kennedy]

Thanks for the further comments.
I am going to give it a try.
Kennidy, I saw that you were on back order, maybe next time. That should be about a year from now at the same rate I have gone through these.

I will post when I am finished and add any thing that I learn.
Michael D

Sounds good. I went back to my board supplier and after a week or so of worming around I was told I no longer fit their business model (read as too small) :rolleyes: so I had to go out and organize drawings, gerbers, stencils, components, BOM, etc and get bids. Also had to purchase new stencil, new programming fees, etc. After all that, the PO has been submitted and we hope to have them ready in February.

A learning experience anyhow...

[TurboDiverArt]

Question. Is the setup the same on all trucks? I thought the newer ones had the ECM involved somehow? Thought I remember reading a while ago that the ECM controls the lift pump or something like that? Maybe I'm all confused, that's typical.

I thought on my truck (1999) the OPS was the thing sitting on top of my drivers side valve cover, towards the back. Approximately above the #7 cylinder?

Art.

[garre1tt]

Hey Art,
Cannot answer your question for sure about the ECM. I do know the same part number is listed for all the 6.5-turbo diesels. At Kragen it is part number, D1808A.
I was working on a 95, last night. Troubleshooting the PMD, because it was running real ruff and backfiring. After installing PDM from the 97 I needed to get the lift pump running. So I pulled the wiring harness off the top of the OPS. Using my high-tech jumper (paperclip), I jumped the hot red wire across to the gray wire for the lift pump. Pump started running rite a way and built up pressure to 9PSI. Truck started right up and ran, like a champion.

Now I know I have two problems, a bad PMD and the bad OPS. Then I found the pool of diesel under my truck. With the lift pump running, giving the system some pressure, the little leak I knew I had became a gusher. Was not hard to find with the stream of diesel coming from the connection on the inlet side of the fuel filter. Replaced the rubber line, I restarted and checked for leaks. Reconnected OPS harness and started just to see what would happen.

Now, the OPS is supplying power to the lift pump. The lift pump is providing pressure, while the engine is running and the whole thing is running like new.

I am confused as to what caused what. Did the OPS start working just for the disconnect and reconnect or was it from the diesel that sprayed inside it while I fixed the leak?
Happy it is running good, but I really do not trust it.

Michael D.

[garre1tt]

Just an update.
It was to good to be true. The OPS stoped working or is only working intermintantly. 95 truck still runs fine as long as I don't get on the throttle.
Fuel pressure runs -1PSI but runs. New parts are in and I got a socket for the new OPS.
A question that I had but did not ask was what size or are they all the same.
They are not all the same, It takes a 1-1/16X 2-5/8" size.

I am thinking about doing a DIY type procedure for this with pitures.
It is really a simple procedure but I have not done it in the past mainly from intmidation and a special tool.

Post if you are interested in this.

Michael D