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Rich at idle Black smoke, with spark knock tbi

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c130fly

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I'm very new to this posting so if do something wrong lemme know,

K, here it is, I have acquired a 1985 k-5 silverado with a tbi system of a 90 or 91 k20 suburban. It has a 1987-1995 tbi crate motor fairly new,
1990 700r4
Edlebrock tbi performance intake 3704
Stock tbi throttle body, did have a Holley setup when I got it,
Chevy 12 bolt rear
208c transfer case
4" lift 35" tires
MSD 8.5 wires
AC CR 43ts plugs gapped to 35
Inline napa p70428 fuel pump
EVRV egr system disconnected and plugged
A-1 cardonde distributer
Fuel pressure constant 13.5 psi
Has 1227747 computer with ASDU prom
When I got the blazer spark knock sensor was removed and it was timed approx 30 after tdc, ??? Black smoke at idle with the smell of fuel
I added the sensor and reset the timing to 0deg with wire disconnected,
Still rich and spark knock while revving and worse under load, replaced plugs throttle body, intake gasket, vacuum lines, ESC, ICM, fuel pressure regulator, added fuel pressure gauge, ECT sensor 3 times, map sensor, IAC valve, (I have 4 of them) computer (have 5 of those), also when I got it the instrument cluster was still the 1985 and no optical sensor was there, replaced instruments luster with a 1988 installed the dash optical sensor it was still wired for it, ran the check engine light for codes and nothing but code 12, usual.
The only difference I can see with the wiring harness is it was setup for the th400 which came with a downshift relay and no 4th gear input to ECM but the truck still has the vacuum switch and 4wd relay for tcc lockup, and for that they looped the egr bleed off yellow wire back to the blue wire. There's no egr bleed off.
So does anyone else have some idea's?
 
Here's one thing to check - there are two different locations for the timing tab, so the balancer must match. It's possible with the engine swap and FI swap, they don't match - then your timing is off like 90*. You could find "sure" TDC and compare to rotor position or try timing it by ear to see if it runs better as you adjust.
 
There is so much off stock it's going to be really tough to help diagnose over the Internet.


The ASDU prom, are you saying it's custom? Or stock chip?
 
To y5mgisi, yeah it's a stock chip for a 1991 ck 1500, that's what I pulled it out of. I've got five computers 3 of them are 1227747 all different bcc' s and the other 2 I have no clue,

To blue85, I saw ur post and was like I set this timing so far counting 6 times, but ok I'll play again, lol, so pulled the plug, removed valve cover and on intake stroke started watching for timing line on balancer, coat hanger in whole, white line in hits zero but coat hanger keeps goin until approx 10 degrees past 0 deg mark? Plateau's then goes down around i guess 15deg, that doesn't seem right, 0 degrees is 0 degrees right? Tdc?
As far as I can tell it's the stock timing cover, never bought a crate motor before so I don't know if they come with one,
Anyway detonated the starter :haha: so i won't know for sure if that's the issue till Monday, so what are ur thoughts?
 
You got an exhaust leak (pre-O2) in that thing, and/or is the O2 sensor working? How does it drive (not idle) when first started vs. once it's warmed up?

Seems odd to me that you are getting spark knock with black smoke/smell of fuel, AND no code. You should never get knocking if fueling is at or above requirements, knock is usually from too lean/too hot.

From what I can see, the ASDU should be ok for your application, automatic 5.7L bin. Obviously not optimal once you start swapping parts, but should be close enough to start with.

You got a laptop? ALDL cable and Tunerpro RT isn't going to hurt, and IMO is eventually a requirement on any GM OBD1 vehicle. With what an ALDL cable costs vs. what you've spent, it's a no brainer.
 
c130fly said:
To blue85, I saw ur post and was like I set this timing so far counting 6 times, but ok I'll play again, lol, so pulled the plug, removed valve cover and on intake stroke started watching for timing line on balancer, coat hanger in whole, white line in hits zero but coat hanger keeps goin until approx 10 degrees past 0 deg mark? Plateau's then goes down around i guess 15deg, that doesn't seem right, 0 degrees is 0 degrees right? Tdc?
Click to expand...
And there's your sign! :doah:

The plateau area is about 5* you say, so your timing marks are about 12.* advanced over stock where you set it!

PING!
 
Yep got a laptop and got the aldl cable, tried using winaldl and then I wanted to try using just the tuner pro before committing to the rt, but I'm not computer savvy and trying to understand the bin, xdf, where to download them and was starting to get a very overwhelmed while looking at winaldl I saw a bunch of numbers ounce I found a setting that worked. Needed a standard to work from, example, spark count 17, is that the minimum, maximum, neutral? O2 sensor .450mv

So when I start her it's about 6 turn overs and fires up, as long as the rpm stays above 900 she won't die when I put her in gear, cold warm doesn't matter, and it doesn't happen all the time, the hotter it gets the more pronounced the spark knock, when at idle she's got a slight miss, quick throttle response though,
Started pulling spark plugs to see what cylinder and about the 4th one I was tired of getting SHOCKED!
Spent the better part of the morning finding TDC, setting the distributor, and the timing mark is about 1/6 off where it should be, I got another question, if it's got a cam in it is that going to mess with the timing mark? And how can I tell?
 
Could also be that the outer shell of the balancer has slipped to get you about 12 degrees off. So when the timing tab says 0, is the distributor rotor aimed at the #1 tower?

How about subtracting about 12 degrees from your whole timing table to see how it runs?
 
Eagle mark, no have not read that yet but going to start,

Blue85 when I set it up at 0 deg I pulled the distributed and lined it up that way, but #1 was always at the 6 o'clock position, but since finding TDC via coat hanger now distributor #1 falls at the 4,5 area and set my wires to match of coarse, now I sure I'm over analyzing the situation but looks factory or at least what it looks like in chiltons. If my local used parts is open 2 mar I guess I'll find out if it makes a diff, man I hope so,
 
tunerpro rt is free, but if you can afford it, it would be nice to register it for Mark Mansur, the creator. I hope he stays interested and keeps improving it.

Knock counts are just that. If more knock is detected, the number increases. O2 mV is just the voltage at the O2 sensor, goes up and down in closed loop if the system is working right.

TDC should be 0*, so you've got an issue on the mechanical side.
 
We'll gentleman, as much as this pains me admit, I'm a knucklehead, I relied to much on the timing marks being right, there were not,
Put the starter in, crank it up and idle high was gone, no more miss, no more black smoke, no more fuel oder, now I have to play with it some more cause the idle set screw is back out completely and tps is slightly out of wack, my fault, but idles all day long 670 +- 20 rpm, backfired through the throttle body a little so advanced the timing a little but no more knock,
I have not test drove her yet and I will update after
So timing chain cover wrong?
Or harmonic balancer slipped?
Throw in ur bets!
 
We'll spark knock gone, and she did really good at idle until she warmed up, black droplets out the exhaust again and when I put her into gear push on gas stumbling bad, :flipoff1: pulled the plugs and all off them were fouled out. Looked at the driver side injector while running, and she's a leaking, wtf! It ripped when I reinstalled them, make matters worse no parts store on this island has um, currently a resident of kodiak ak and only 2 stores, anyway had a old tb lying around and stole the rings of it, they were flat but holding for now, to scared to restart her again tonight so I'll see what tomorrow brings...

This thing is starting to leave a bad taste in my mouth,
 
You need to oil the O rings in motor oil so they slide in correctly. Injectors only go in one way... correctly. Look for the notch and line it up, one is front, one is back. Not the same on each side IIRC...
 
You could just put timing tape on the balancer to time from in the future - maybe things won't move around anymore. Or as a quick fix, find your real TDC again and paint a white line.
 
As many timing marks as were used (at least three I think) and PO's being PO's, who knows?

If there is any question the balancer has moved, I'd replace it. Often you can see the rubber swelling, cracked rubber, or outer ring not aligned with the inner if they are bad. I suppose if you scribed a line between the outer and inner ring of the balancer you'd know if it moved again.

Someone must have a pic of the "proper" timing mark/cover for an engine your vintage.
 
We'll, that's the next thing on the list, harmonic balancer, and timing cover, here's an update, took her on a stroll today and she performed beautifully, the drivers side injector still putting out droplets so new injector on the way, and there is an exhaust leak at manifold, u can hear it know with no knocking, also still need to fine tune the idle air speed but at idle I can't even tell she's running, not bad for a grand total 3500$ including price of blazer,
I gotta figure out how to load pics up here,
Next paycheck tuner rt!
:thumb:
Oh guys thank u so much for the inputs and I will continue to update.
O
Ahh who am I kidding 1200 in parts SUX!!!
 
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