Thanks Jim, that's good to know. I don't know if I will mess with it much or not, though since it's not my SG and I'm only borrowing it. I would hate to mess it up so it won't work in the owner's truck when I give it back. I will look again and see if it will display the TPS voltage as well. If I can figure that out without much trouble I may just look at that, otherwise I'll just check it out with my DVOM. Can you remind me again what the test procedure and parameters are? I'm thinking 3.5V at WOT comes to mind, but I can't recall.

According to Oldwoodsdiesel, the SG reading for BARO can be calculated by figureing the difference between the MAP value and what it calls BOOST. Apparently MAP minus BARO is the way it figures the value for BOOST, so you can calculate MAP by looking taking BOOST minus MAP.

Hopefully Friday or Saturday I will get to mess with it some. The weather looks like it may clear up some next week as well so I may be able to take it out for a drive and do some more testing then.

 

Nate, cant remember but think it's more like 3.87 or so. Theoretically MAP and BARO are the same with key ON engine OFF. When the engine starts and you drive MAP goes up but BARO remains constant, unless you are climbing a really big mountain. That's where the BARO sensor comes into play as then, and only then does the PCM need to know the difference. SG, unfortunately does not do the calculations and only reports absolute MAP.

Had to go out today and do some chores so set SG to view ICP and %. I was in town but had a couple opportunities to floor it in second gear (auto) and the best I could achieve was around 2600 - 2650 PSI and IPR at about 34%.

 

Does your SG not have an option to display a "boost" parameter? MAP should be an absolute value (and yes, key off it should be equal to the BARO reading) but this one shows BOOST and supposedly it is the MAP pressure adjusted for the atmospheric pressure (from the BARO) and displayed that way. So at idle it should read more or less 0 and go up from there. I was told that this is how you double check the readings of the BARO using the SG.

That seems to be about where my numbers top out too, but I can give it WOT in 4th (manual) and it never goes much above that. Maybe that's all I should expect out of the stock HPOP but several other have reportes seeing a lot higher numbers than that out of theirs. In fact, I can get higher ICP numbers than that out of my old truck, with more miles on it.

 

Nate, yes it does. SG not only displays MAP absolute but also voltage, if that is what you want.

Review the operators manual, especially the last few pages describing the PID supported for each platform. I understand you not wanting to reprogram a borrowed SG, totally, your call.

sorry, wrong link, use this one ... http://www.aeroforcetech.com/files/I...AL_rev_2_7.pdf

http://www.aeroforcetech.com/files/I...AL_rev_3_7.pdf

 

Well guys, I got to mess with this thing again today for a while. And here is what I found.
CCT, passed
Buzz Test Passed
I think the BARO is okay because before startup or at idle I get about 14.4 PSI on the MAP and 0.1 or so on the BOOST reading. That's close enough for the margin of error in my opinion.
I tried setting the SG to Build 1 (or whatever they call it) and I wasn't able to pull anything for the TPS position or voltage readings. I'll have to test that with my DVOM if I need that data, but I don't think that's my issue. Because.....
I also pulled the DTC's (I would have done this sooner but I was a little afraid to mess with the SG too much) and I got the following codes.
P0472
P0603
and finally.....
P1280.
The first 2 are KAM (I changed the batteries) and EBPV (It is unhooked), but that 1280 points to an issue with the HPO system.
So at this point, I'm wondering what is the easiest thing for me to start with. IPR? ICP? Injector o-rings?
I did the rev test after things got up to temperature and I may get just ever so slight a slow in the rev at around 2500-3000 RPM but there is no stumble really. I also don't see any discoloration in the Fuel Bowl or filter which leads me to believe that the o-rings aren't the issue. I really don't want to do o-rings, I'd rather just put those dollars toward a set of Jim's budget Stage 1's, but then I'm looking at a chip as well to run them right.

I guess the logical thing to do is to take it out and drive it when the roads clear up and see if I can set the code again. I don't recall ever seeing the CEL come on, so maybe it happened when the PO had it, I don't know.
I'm open to input at this point.

 

I still think I'd pull the ipr. If it doesn't change with the icp unplugged, that would be where I'd look.

 

X2^^^^^^^^^^

 

Nate, P1280 will throw if ICP is unplugged for testing purposes? Is it possible your CEL bulb is burnt out? Unplug the MAP and start, the CEL should immediately come ON.

Interesting thing is you have no codes indicating poor performance. Anyone in the past do the 10K mod or does the wiring to ICP connector look original?

Just thinking out-loud.

 

So you recommend taking it out for a ride with the ICP unplugged and seeing how it runs?

CEL works, for sure. It has come on when I have had the MAP unplugged for testing.

I think the wiring for the ICP is all original. As bone stock as everything was when I got the truck I would be really surprised if it ever had a 10k mod on it.

The break in years for the edge filter on the IPR was between 95 and 96, right? So the IPR for a 96 should work in my 97, right?

I guess worse come to worse I could take it out for a good run and see if the code comes back.

 

Four variations of high-pressure oil pumps exist.

– 1994 1/2 to serial number 187099 have a check valve but do not have an edge filter. The edge filter was part of the injection pressure regulator.

– 1995 with serial numbers 187100-201680 have a check valve and the edge filter went integral.

– 1996 starting with serial number 201681 the check valve was eliminated but continued to have an integral edge filter.

– For 1999 1/2 model year, serial number 869812 and above, the flow rate has increased from 6.8 cc (0.41 cubic inch) per revolution to 7.2 cc (0.44 cubic inch).

 

Alright, well I should be fine then because both of the engines were after '95 but before the 99.5 17° HPOP. I guess I will plan to take a ride with the ICP unplugged and then maybe I will swap in a different ICP and try that as well. If none of that seems to help, then I guess I will be looking at swapping the IPR in with a new o-ring on it and see if that makes any difference.

 

I don't think swapping in a new icp will make a difference. It's a needed sensor in the scheme of things, but if the computer isn't reading anything from it being unplugged the pcm will use a default number, report that to the ipr, and it should run ok, but with a cel.

I guess that is an easy sensor to swap so you could if you wish, but I'm still thinking the ipr.

 

That makes sense Darin. And by all accounts the ICP seems to be reading correctly because it does drive like it is low on HPO pressure. It runs good, it just doesn't have a lot of grunt when you drop the hammer, if that makes sense. I think I might still try the ICP just for S&Gs since it is only going to take me about 5 minutes to try it.

I will probably end up waiting on the o-rings for the IPR too anyway since I don't have a set here. I think I may order those this morning but even so, I doubt I will see them before Tuesday or Wednesday. This will give me something to try before then.

 

I didn't have time to mess with the ICP tonight before I took the truck to get a new windshield, but it's safe to say that the issue was not IDM related. The best I could get it to do on the way to the glass shop was about 2600 PSI at 36% Duty Cycle and that's with the IDM110 in it.

At this point I'm still waiting on the IPR o-rings (danged USPS). I was hoping they would show up today, but they didn't, maybe tomorrow I guess.

Edit: Well, forget that. USPS is saying now that I won't likely see the o-rings until Thursday. I should have just ponied up the dough and paid the extra for UPS shipping, but it was going to cost as much as the parts.

Patience is a virtue, right?

 

I got my o-rings from Riffraff yesterday. I tore down and cleaned the spare IPR that I have and got it put into the truck but I ran out of time to finish putting it all back together before I had to leave for my night classes (man will I be glad for a break here pretty soon). Hopefully I will be able to get it all put back together this evening and see how it performs. The o-rings on the IPR that was in it didn't look bad at all, but the solenoid is loose in the metal housing that it lives in. I think I have seen them like that before, but the spare I swapped in was tight in the housing.

I probably would have had it done last night, but dad wanted me to check the wheel bearings in his Ranger, so I wanted to be able to pull the truck out instead of doing all that in the driveway in the rain. It's probably for the best because I want to take some time to do some cleaning in the valley and around the engine compartment before I put everything back together, but I'm hoping to get to it tonight.

I am taking my son out for his first trip deer hunting for a while tomorrow for a while, so I don't know if I will have a lot of time to spend on it then, but hopefully before the end of the weekend I'll have it back on the road. I've got firewood to cut and haul so I can't afford to have it down for too long. Hopefully I'll have an update soon.