69 Van Project update

**AzDon** · 10-01-2022

First, I want to thank all of the folks here that helped me with schematics and with my thought process in figuring out how exactly to accomplish a running vehicle through sorting and cleaning up a "rats nest" of a factory harness....It was here that I gained the courage to believe that moving a factory GM harness to a vehicle could even work....

It's been a couple of years journey building my van to incorporate simple 90s era GM TBI...
I decided to use a TBI305/700r4/323posi from a crashed 91 wagon because I also drive one as a daily and have several good wiring schematics and the Factory Service Manual (FSM)....

I was going to use a TBI454/4L80e from a 95 burb, but it just didn't look like it would fit comfortably when I started measuring....
I accepted the challenge of massaging the factory TBI harness to fit the vehicle, keeping all of the sensor utilities that I thought might matter to the ECM and even putting toggle switches on a few unused wires in case they matter.....
So my question today is about Timing.....
I timed it at 0 degrees with a timing light with the "base timing" link unplugged as the FSM says to do it....This resulted in 17 degrees while idling at 500rpm with the connector plugged back in....
This van runs freakin AWESOME!....It idles good, no dead spots, no misfires, no gasping of the IAC......
The problem I'm having is that within about 10 minutes of heading out, the temp creeps past 230 degrees and was past 250 yesterday after about 15 minutes out....
I set it up with an ebay aluminum radiator slung pretty low with an electric fan from an 84 z28 and custom shroud.....It has a thermostat housing radiator cap and I also have a factory 7 blade fan and clutch moving air through.....I have the heater hose looped (no heater) and the 700r4 is cooled by the radiator only.....And I'm running without a thermostat...
I'm going to install one of my custom locked fan clutches and maybe put a separate cooler for the trans.... Also some type of large heater core with a fan on it as an additional radiator, but I want to start simple (and cheap)

Is there any point in pulling back on the timing, or is the ECM just going to override any adjustment I make physically?

I think ultimately, adding cooling capacity and air movement is going to be the answer, but if I can solve the issue more simply, I'd be thrilled!

profile painted.jpg powerwall1.jpg turnedout4.jpg boxedengine2.jpg

**In-Tech** · 10-01-2022

Way cool project :)
I noticed your egr is not connected. If you are using a stock file, when the egr goes active in the calibration it will pull fuel away "thinking" the egr is working. If you have the ability to turn that off in the chip, do so. Otherwise you need to get the egr solenoid in there and hook all that up.
Is it a "new" water pump? Does the temp seem to cycle? One thing I have run across is the wrong backing plate on the water pump and it was cavitating.

**AzDon** · 10-02-2022

Thanks for the reply!..... The water pump is new ACDelco from RockAuto......The temp just creeps a couple of degrees at a time, not losing any temp (cycling) as it rises because I have the fan running full time and no thermostat.... My wagon runs 130-160 all the time set up like this with A/C blowing ice cubes in 110 degree weather
I had disconnected and plugged the EGR stuff on my daily (wagon) and it runs fine so I didn't even run wires for the solenoid..... (mistake, I guess)..... I also don't have the stuff for the Air injection in place...... And the exhaust is bullet glass-packs after the 1-wire oxygen sensor in the right pipe (only reading one side)....I guess I should pull spark plugs and look for lean-ness.....
This radiator was listed as being for a big-block early Camaro and looks very nicely put together, but I'm suspicious (chinese)..... I've ordered a 32lb cap for the radiator itself because the engine's fill level is quite a bit higher (16 lb cap on t-stat housing).....
Are you saying the EGR stuff needs to be fully operational to provide richness that the ECM is pulling? Is there an external work-around other than a re-flash?...
Is 17 degrees of timing at no-load idle okay (?) as that is where zero degrees in base timing puts me when I re-connect the link.....I always set about 8 degrees in the carbureted era.....Can timing be backed out physically, or does the ECM just put it back?
I realize these are kind of noob questions..... I'm not really a "tuner", I just want the van to run reliably without further thought once I got it dialed in.....
I'd be okay with buying a reflashed chip, but I really haven't studied up on reliable sources.... Any suggestions?
Right now I'm limited to within six blocks of home and it feels like house arrest!...

**In-Tech** · 10-02-2022

Are you saying it has heating problems even at idle? The egr is only active at light throttle. Shoot me the alphanumeric broadcast code that is on the silver sticker on the chip.

**stew86MCSS396** · 10-02-2022

What's the part number on the water pump and what application did you order it for?

**AzDon** · 10-02-2022

The water pump is AC Delco 88926233 ordered for 91 Caprice (serpentine reverse rotation)....
The ECM is 16136965 with a four letter code of AYDM
I haven't pulled the cover to look at the chip yet.....
The two episodes of building heat were during test drives around the neighborhood which is easy driving under 35 mph.....Next I will try just starting it and allowing it to idle....
Driving it would also put transmission heat on the radiator....
I forgot to mention that I do have a remote oil cooler mounted away from and completely divorced from the radiator.....
I think I'll check everything with an infrared thermometer and I might try knocking the timing back a couple of degrees....

**Moofus02** · 10-02-2022

No thermostat will do that. Water passes so fast it can't transfer the heat. If you don't want a thermostat gut the center out of one for a restriction. That should fix the issue

**AzDon** · 10-02-2022

So, A bit more background...
The radiator is in the factory location, but lowered 3 inches and has an aluminum under-scoop that is the width of the chassis out to the front leaf hangers.... It has an electric fan from an 84 z28 on a custom shroud with no gaps....The engine is 18 inches back and maybe an inch lower than stock and has a factory serpentine rotation 7 blade fan with a clutch, basically there to move air through.... I built the doghouse extra large and aero inside to help move air through.....I gutted a thermostat and re-installed the disc to partially restrict the flow, but mainly to provide a proper sealing surface for the gasket....
The electric fan turns on automatically at 190 and off when it cools to 174..... the sensor for that is screwed into the heater-hose port near the distributor.....
I did an idling test, in gear against the e-brake....
It took 25 minutes to reach 190 and turn the fan on
2 minutes to cool back to 174
3 minutes to hit 190 again
2 minutes to 174
turned the fan manual switch on and it dropped to 158 in about 5 minutes
put it in neutral and it got to 152 about 4 minutes later....
Never went past 190 for this test because the fan kicks on and it apparently has enough cooling capacity to idle...never lost a drop of water from either 16 lb cap.....
It's low-stall, so it did have some load and a bit of transmission heat........
It's 95 degrees here as I'm doing this test.....
I guess my issues only show up when I'm driving it around the neighborhood which is max 35 mph...
I'm going to try a 32 lb cap on the radiator (16 Lb cap at the t-stat housing fill) and a locked fan clutch first and then probably pull a couple of degrees of timing before trying a divorced trans cooler and some kind of heater core hanging under the van.....I'm also willing to consider that I need a modified chip with EGR and A.I.R functions erased.....

**In-Tech** · 10-02-2022

Hiya Don,
Great info, I don't have a copy of that chip in my archives. My info shows that to be a 27256 memcal. Shoot a pic of it under the cover when you get a chance. I would definitely turn off the egr in the chip as a good start. I love your project, I'd be glad to reprogram that for you, the rub is your van will be down a few days shipping back and forth.

After you try retarding the timing, advance it about 4-5 degrees with 91 octane. This will lower underhood temps drastically. I'll do the rest in the chip so you can put it all back to stock. I am not sure if the 91 caprice base timing is zero, check into that too.

**AzDon** · 10-03-2022

Thanks Carl....
It's actually Olds Custom Cruiser and I got the zero degrees spec with the base timing link unplugged out of the FSM for these cars....
Zero degrees becomes 17 degrees when I plug the link back together.... I'm thinking thats a bit much, but I'm wondering if physically retarding it will work (?) or if the ECM will just override my changes(?).... I have just been using 87 octane and hadn't thought about lowering combustion temps with 91 octane....
The chip mods seem like the most logical starting point, but unsure....
What would/should it cost me to get it done?.....How would I package and ship for best results?
I just pulled the cover and the black plastic covered item on the right that looks like it might unplug has a foil strip showing the letters BCDU and numbers above that with their top halves covered looks like 1010 or 1818 or 1313 or 1616 or any other combination with two 1s in first and third position...There was also a scan code sticker on the board #s 435091112751157
This is my first time inside an ECM and I'm unsure what precautions or care I would need to exercise while removing/handling this stuff...

**In-Tech** · 10-03-2022

Hiya,
The ecm is a dumb box, it doesn't know what you do with the base timing, it just does its' business assuming base timing is stock. The only reason I suggested 91 octane is just for safety if you advance the base timing.
For this project, no charge on the labor. USPS priority mail small box(I think it's ~$9) is easy.

Do you have or know where another one of those vans is? I see an LS swap in it's future if you do. Maybe a corvette ls3 drivetrain, torque tube and all

**AzDon** · 10-03-2022

I actually have a donor c2500 Suburban (95) with a 454/4L80 that I fully intended to use until I started measuring......Being that the engine's cabin is fully surrounded by the travel cabin, I considered it VERY important that there was ample air space inside there for it to breathe and even more important, exhale hot air....
I've been eyeing the Blueprint 350 that has big aluminum heads, roller cam, a dyno sheet proving 341HP and a 50 month warranty for under $4100......
Funny, but folks are too busy chasing used 5.3s to have any interest in this 454....
Where are you located? These vans are out there for sale pretty frequently, but rust and pricing are becoming problematic...
I just passed on one a month ago for $800 in SoCal....but deals are getting rare.....

**In-Tech** · 10-03-2022

I'm in central cali. Yeah, the LS swap crowd is a growing thing. I just dragged home a '78 C2500 "Fall Guy" truck. I am building a ~500hp 6L 4l80e for it.
Man, your project is begging for a tuned port intake, massive increase in torque and fuel economy, the cool factor too. It might end up being all you want for now

**AzDon** · 10-03-2022

Our local YouTube car guy Merlon (Merlons Old School Garage) is hooked up with the local towing guy, marketing and installing LS engines, mostly in Jeeps....
I prefer pre-LT1 stuff and actually kind of happy that nobody else wants the stuff (My mom had an LT1 Camaro and the optispark was a PIA)....
This van already runs better than the 66 short van I had years ago with a 396, but I've got to get comfortable driving it before I can consider upping the power because it's the first vehicle I've driven in years without power disc brakes or power steering and it's still on a straight axle with leaf springs.....
In addition to the 18 inch engine setback and rear posi, I did a front axle flip and set the accessory drive up with dual alternators with the second one wired separately to it's own battery, which can be tied in with the other at the flip of a switch.... It also got an in-pump tank spec'd for a 88 van.... I've been working on it since 2014...
I have a couple of build blogs here: https://vintage-vans.forumotion.com/t59138-azdon-s-108
and here: https://vintage-vans.forumotion.com/...-ready-to-roll
I also share lots of advice and opinions regarding building and setting up first and second gen chevy vans (none related to fuel injection)
I hope to move on to installing an interior in this van and maybe finding a next project to be the home for this 454 I've got (or MAYBE I need to re-measure for fitment in this van)
Oh, the "dumb box" comment..... Would cutting back base timing 2 degrees pull the whole curve back 2 degrees, or does the ECM just ignore the mechanical setting of the distributor completely?....
Also, the idea of putting Corvette independent suspension under one of these vans is very intriguing because the factory unibody is tucked WAY up under the body, so it could literally be dropped onto a chassis, while hiding it well and still being low....The vans are relatively wide, using axles that are 65 inches drum to drum.....Independent suspension solves the issue of too-short driveshafts.... Sorry to ramble...