My 88 C1500 "The Go-Get-Mobile"

[PlayingWithTBI]

BACK TO TUNING - AKA "Which way do we go, AE, SA, PE, VE, AFR?" Un-huh Un-huh!
As I mentioned earlier, I started with a "mail order" tune and wasn't happy with it. Then I went to Dave w and started really tuning with data logging. We started with the same SA table as Harris had. It's pretty aggressive but, again, the 7747 only goes up to 3600RPM.

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Here's the "Main Table" from the EBL. Notice I flattened out the advance when near idle because I was having a hard time getting it to stop stumbling @ idle.

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Plus, the EBL has an extended table that goes up to 6375 RPM but, I run out of springs and cam when I get up any higher than 5200RPM.

Here's a spreadsheet, I stole with pride, from @84ELKY who posted it on thirdgen.org and gearhead-efi.com, you set your all-in advance and adjust limit advance/increase Kpa, then you can go into the cells after max SA to reduce/increase drop off. The table above came from this workbook.

 

[PlayingWithTBI]

One thing we agreed on, with these "Fast Burn" design heads, anything over 32* adv at higher revs, won't work. When I was doing 0-60 WOT logs, I noticed I was getting KCs at lower revs while higher KCs were understandable with less spark reduction after all-in.

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Then it dawned on me that my SA Launch mode was adding a sh*t load of spark.

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After I reduced that, I got less KCs at lower revs.

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Here's what I did to the SA Launch table.

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Still on the ragged edge but way better than before using the spreadsheet. Don't pay any attention to 600RPM/40MAP - that was starting the engine, ha ha.

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[PlayingWithTBI]

As I posted earlier, I started this project with the bored 46mm Throttle Body with "Ultimate Mods" and an 18Lb spring. It was performing pretty well and I didn't think I needed changes there. Well, after I switched to the EBL I was data logging and that's when I noticed my injector Duty Cycle was 109% at 5200 RPM! That meant that they were open all the time - not good.

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That's when I bought a 28LB spring for a 94 7.4L and an AFPR with gauge. We rebuilt the TB along with these upgrades and installed them, set my pressure at 28PSI.

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After that I took it out for a run - much more better, 84% DC @ 5375RPM!

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After a couple Months, the 61LB/Hr injectors started dripping at idle causing a more pronounced stumble. I ordered a pair of 7.4L injectors, and put my 18LB spring back in, set the pressure at 15PSI (as low as I could go with that spring). That's when the EBL while tuning VE tables, started shutting them off altogether. After I set my SA and VE tables flat around idle speeds and MAPs it would idle somewhat but stumble so bad it would die every so often. So I went back to the 61LB/Hr injectors and set my pressure to 20PSI. I'm now running a DC of 90% @ ~5200 RPM - good enough!

I still couldn't get rid of my stumble @ idle in Closed Loop. Just for ***** and giggles I switched it to OL @ idle and it smoothed out once I set my OL timing flat @ 18*, YAY!

 

[PlayingWithTBI]

Moving on to AE (Acceleration Enrichment) This is basically like an accelerator pump in a carb. It gives an extra shot of fuel when you hit the gas.

Now they say to keep reducing AE until the engine bogs down when tipping in, then add some back. Too high of AE and it'll hurt your MPGs too. Every so often I'm reducing some, and sooner or later I'll get there but, I don't drive it enough to worry about MPGs.

On to PE (Power Enrichment) which richens the air fuel ratio during times of hard acceleration for more power. Similar in function to power valves in a carb.

I've been playing with PE to see if I can reduce KCs by adding more fuel to maybe help cool the combustion chamber some. I had it set as low as 11.8 @ higher revs. According to my WBO2 it's getting down to ~11.1. Now I'm raising my AFR some to see if I'm losing performance by being too rich.

Here's my AE and PE settings a while back

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And now my most recent settings. So far I'm not seeing much difference.

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[PlayingWithTBI]

Door Locks Repair
It's been about 5 years since I was able to lock the doors, they got so stiff, my daughter broke off the key in the passenger side. It really didn't bother me much since all I used the truck for was to go get lumber/supplies and an occasional dump run. Oh well, why not? About the same time we did the muffler, I bought 2 lock switches, 2 lock actuators, and 2 door locks. Pulled the panels off, note the rubber flaps for the door vents (on the lower left) are still there and flexible after 32 years, ha ha.

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Drilled out the 3/16" rivets (2 ea) for the door lock actuators, the 3/16" (6ea) for the door handle and switch connectors housings. Then wedged the windows up and drilled out the 1/4" (4 ea) rivets for the regulators.

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Removed the inner panel, now we have room to get to the door locks and outside handles. You can see the upper rod for the door lock and actuator. The angled rod is for the door handle.

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We removed the outside handles and replaced the door lock tumbler in them. Now it's time to put it all back together. For the rivets, you need a big rivet gun, something like this from HF (for around $30).

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We bolted the inner panels back in after greasing the rod guides, manual door locks, and window tracks with white lithium grease (everything that moved). Then we riveted in the window regulator with the 1/4" rivets.

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To be continued...

 

[PlayingWithTBI]

Door Locks Repair, continued.
Next we riveted in the housings for the door handles, door locks, and switches connectors - normally takes 6 ea 3/16" rivets but the upper left ear on my driver's side broke off.

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Then installed the actuators with 2ea 3/16" rivets. In case anyone wants to know, the door lock switches and connectors are all the same, they're just wired differently on each side. Here's a look at the passenger side's - 5 wires to each lock and window. BTW - it turned out the passenger side switch was bad, everything else worked, go figure!

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I cleaned up the door panels a little and replaced all of the panel clips. Each door took 11 clips.

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Now I have electric door locks, keys that work, and the windows go up/down about twice as fast as before! A good day, we got it done in about 2-1/2 hours working together, after we did the muffler.

 

[PlayingWithTBI]

The other day I was driving home and, all of a sudden, the engine got louder. I pulled into my shop and popped the hood to see what's going on. Found the passenger's side header gasket blew out. You can just see it sticking out from above the flange. Notice the oil on the valve cover which was leaking out from under the PCV valve grommet.

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Of course, with the A.I.R. (smog) pump in the way, it's almost impossible to get to the header flange bolts.

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My son brought over a collection of various limp-dick sockets, we removed the A.I.R. pipes and stuff to get to the flange bolts. Plenty of room to get the gasket out.

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He wound up using this combination. That little 1/4" drive ratchet setup gets into tight places and delivers plenty of torque.

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Here's the gasket, it burned through and blew out in 2 places. The driver's side blew out last year. Now I have new Cometic gaskets in there. The original ones that came with the Summit Racing headers are junk!

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More to come, I wish I could post more than 5 pictures at a time!

 

[PlayingWithTBI]

Continued from above.
We added grade 8 split washers to help keep the bolts from coming loose.

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We put it all back together, cleaned up the valve cover, grommet, got a new PCV valve and hose end since the old one (on the bottom) was stretched out.

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Then we glued the PCV valve grommet to the valve cover with some Permatex "The Right Stuff" and I clamped the other end securely - no more leaks, YAY!

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[PlayingWithTBI]

Today we went to get wood for building a couple 42" wide cabinets with drawers for a friend of mine's wife's kitchen. Got 7 sheets total for the carcass and drawers on the bottom and 35 Board Ft of 4Qtr (10' lengths) straight-line 2 sided clear Alder for the face frames and drawer fronts on top. Drove 86 miles round trip, ~78MPH on I-10 in OD. Engine stayed cool and A/C worked great in 100*+ temps. Who needs a long bed truck, LOL?

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The neat thing about having the trailer is, I can back in into my shop, leave it there, and pull wood when I need it instead of having to unload the truck and store it somewhere. I guess I'm gonna be working on this for a while instead of playing with my truck, ha ha. If anyone is interested they're gonna look kinda like this (stained to match her other cabinets), I hope.

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[5speed Hoopty]

Extremely helpful. Thank you.

My 1990 C1500 had "RED" interior. More like garnet red, however, your post has given me a few ideas in regards to matching the dash now that I have replaced certain pieces.