SenorNoob's '88 Ext Cab "Build"

[SenorNoob]

Found something interesting.

That's an Intel 8061 processor.
There is a relevant book here. <--PDF Warning

 

[scotts90ranger]

Maybe. That's why I said not to take my comment too seriously. But my thought is that the pcm is trying to calculate how long to open the injectors. If the pressure is steady, that's easy. If the pressure keeps changing willy-nilly, how do you calculate how much fuel will flow through an injector in 0.xxx second?

Or maybe I just don't know squat about this.

It really depends on how the system works, most current stuff uses a constant fuel pressure because the injector drivers are more precise and such but back in the day they used a thing called "injector tip delta pressure" which pretty much stayed the same with a vacuum compensated fuel pressure regulator. This allowed to have bigger duty cycles at all the time so the calculations were easier... That pretty much went away when the evaporative emissions requirements pretty much made them put the fuel pressure regulator at the fuel tank to run returnless fuel systems to have less surface area of fuel lines

That said the dropping of fuel pressure at key off doesn't surprise me, gas is nearly incompressible as a liquid and the only thing holding the pressure is the check valve on the outlet of the high pressure pump, if it's seat isn't perfect it doesn't take a whole lot of volume to drop fast...

Don't know if that's OBD II or not, I'm guessing no but I learned a fun thing on my '97 Ranger last year when I was having a hard time accelerating when it was hot out, the spark advance was going to 5 degrees after top dead center (IE my OBD II reader was showing -5 advance) when it was hot out, I put a resistor across the air temp sensor making it think it's 80F out and it drives great!

 

[SenorNoob]

This definitely has a vacuum referenced FPR.

The more I look at it, the more I think this PCM "should" handle live data. At like 1 per second data rates not really live, but close enough for my purposes. Unfortunately the last scanner that could read it seems to have been discontinued around 2000. Bosch 1300.

 

[SenorNoob]

Washed out under the hood the other day and it wouldn't start afterwards. Gave it like 5-10 minutes and it started fine. Went back the next day and drowned the coil pack and crankshaft position sensor and it started fine. Then wouldn't 10 minutes later. Tach was moving slightly while cranking so I'm guessing the CPS was working. Fuel pumps were running enough for the FPR to do things and let pressure back to the tank. (I could hear it spraying back into the tank.) Then on the drive to the creek it was missing right as I went to take a left turn. Cleared up some as soon as the g-forces went away. Makes me think something has to be loose. It's really weird that all this started after getting some bad gas...

Actron CP9190 is supposed to be on the way. It does live data on these. Hopefully my PCM does. I know the 91 harness has the wiring for it. I wouldn't think Ford would've had it on the Explorer in 91 then removed it for 92, but ya never know...

Toss up now as to whether it just dies before the scanner gets here or not. (Estimated delivery on Wednesday. I have a Dr. appointment and grocery shopping on Thursday so it'll probably be Friday before I hook it up.

 

[sgtsandman]

Intermittent issues are the worst. It's kinda hard to troubleshoot something when it's working.

 

[Curious Hound]

Intermittent issues are the worst. It's kinda hard to troubleshoot something when it's working.

I think it's easy to troubleshoot something when it's working.

"I troubleshot the nuclear superheterodyne hyperamplified retroencabulator. All test results satisfactory. It's running like a top. No further action required at this time."

 

[SenorNoob]

Did a little more troubleshooting today. I have been watching the tach when I turn the key. I should've been looking for the check engine light.

That ground is directly from the EEC relay coil. It was on a screw with the power distribution box. That screw was backed out about a 1/4in. It's now on it's own screw and sanded clean. I seriously thought about just extending the wire up to the battery negative post, but I have too many things on there already.

I went for a quick test drive after fixing that, And now I wonder if the EEC has been flickering for years. First time it's ever pulled above 4k. Came back and ran codes. I had a slew of them (173 411 538 KOER and 565 172 452 543 KOEO) it's sitting right now with the battery ground disconnected. I'll take another trip in a few minutes and see what I end up with.

I suspect I need to clean out the tank. I think it may still have water in it from the bad gas a couple months ago. I'll try to keep a minimal amount of fuel in it till I get a chance to do that and swap the sender and lines over. Too bad I don't have at least the longer u-bolts to get the blocks in while the bed is off. The intent was to hold on to that till I could do everything at once with the bed off. Including a body lift.

Really too late now to get the house project underway for the 4th weekend. And I still don't know what my schedule for work is gonna look like that week.

 

[SenorNoob]

So more work.

I ended up changing the TPS. Computer seems happier with one that reads 0.8-4.4 than it was with 1-4.5.

Now got 111 KOEO. 452 Continuous Memory. And 412, 173 KOER.

So it doesn't like the speed sensor. I need to see if I have one on another transfer case. Otherwise it doesn't seem sure if it's idling too high or too low and whether or not it's slightly too rich or too lean. Idle is very steady normally. It goes nuts when the KOER test runs. I may try to clean the IAC or swap it out. I have at least one more.

Feels like an overloaded mini bike (Think 5hp Briggs) under 2k. Pulls great from there to 4k. Unless it's in overdrive.

I'm off to bed now to sleep on it before work.

 

[SenorNoob]

Well, 3 tries to start before work. 5 after. It is almost out of gas though. I'm gonna park it and drive Brittney's truck till I have time to get the bed off, clean the tank and swap to the single in-tank pump. Then I can get 5 gallons of ethanol free and go from there.

 

[SenorNoob]

CP9190 is here. It does read live data. Nothing really abnormal IMO. All other test require it to be powered by the vehicle. I didn't get that cable or the disc with software. I did find the software on Actron's website via the Wayback Machine. Data recording is limited to 30 seconds and updates every 2 seconds. So it's literally just 15 snapshots. The owner's manual actually has specs for the power adapter. 5.5mm x 2.5mm barrel jack. (That's supposed to be the same as CCTV connectors, but the ones I have here the center is too small.) Seems like the length should be in there somewhere. The manual even recommends battery clamps for vehicles that cut power to the lighter socket when the key is off.

I'll try to post a couple snapshots this weekend sometime.

I ran it long enough for the ECT to get up to 180 and closed loop to take over. STFT was +/- 3%. That's at idle. I need to find a way to get readings inside the truck.

 

[SenorNoob]

It hasn't gone well. I thought maybe the intermittent longer starts were fuel pump related. Nope. New high pressure in-tank pump, sending unit, lines, and filter. No difference.
Fixed several small wiring things. No difference.
At least I did get the shock mounts on while the bed is off.

The only thing even slightly odd I noticed today was that the first time I went to start it was that I had to try 3 times to get the scanner to connect for live data. Once I got it connected it fired instantly. It does fine if you start it every couple hours. Left it set for 5 hours though and it usually takes 30 seconds to 2 minutes of cranking before it starts. The only consistent code I've had for the VSS. It never had anything but 0 on the scanner. Even when I drove it around the yard. I know it's spinning cause the speedometer works. I have another one on a transfer case that I should swap.

I can't catch it actually not working for long enough to check everything. I do have remote start button and spark test lights (It was a packages on Amazon.) on the way. It's almost like Brittney's S10 where it has to be turning enough to have built oil pressure to turn the fuel pump on. I know that's not what it is tho because it has fuel pressure from the first cycle of the key. Frustrating.

If you made it through that wall of ranting: Some pictures in no particular order.

Shock mounts installed:

What came off:

How long ya think that driver's side was good for? LOL

New sending unit with Kemso pump fitted:

How much had to be cut off to make the pump fit into the sending unit.