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[TurboPirate]

Hello guys, I am working on a Chevy Astro 1986 4.3 V6 engine and want to adjust the ignition timing specs, the chilton book tells me to use the sticker in the engine's bay but that sticker is no longer there, I have google the thing and found nothing, do any of you know or have a chevy astro 1986 V6 with that sticker on the rad fan cover? Thanks in advance TURBO.

[budmanmikey]

Hello guys, I am working on a Chevy Astro 1986 4.3 V6 engine and want to adjust the ignition timing specs, the chilton book tells me to use the sticker in the engine's bay but that sticker is no longer there, I have google the thing and found nothing, do any of you know or have a chevy astro 1986 V6 with that sticker on the rad fan cover? Thanks in advance TURBO.
If you are still needing that info i can get it for you in the morning when its light out. my buddy has one right across the street that is wrecked. I am sure i could get the info or maybe mail the sticker to you. Let me know.

[TurboPirate]

If you are still needing that info i can get it for you in the morning when its light out. my buddy has one right across the street that is wrecked. I am sure i could get the info or maybe mail the sticker to you. Let me know.

Yes still need that info, thanks a lot.

[budmanmikey]

Yes still need that info, thanks a lot.
I'll get back to you in the morning. If i can remove it safely he says i can have it, maybe i can take a picture and upload it for you.

[TurboPirate]

I'll get back to you in the morning. If i can remove it safely he says i can have it, maybe i can take a picture and upload it for you.

Thanks, no need to remove the sticker, the photo will do

[no-one]

0 degrees at idle on 4.3l engine disconnect 1 wire (tan with black stripe)connector at distributor. check and adjust engine timing when engine at normal operating temperature in park or neutral . when done reconnect wire ...to clear codes remove ecm fuse for 10 seconds ...when using a timing light .
hope this helps

[TurboPirate]

0 degrees at idle on 4.3l engine disconnect 1 wire (tan with black stripe)connector at distributor. check and adjust engine timing when engine at normal operating temperature in park or neutral . when done reconnect wire ...to clear codes remove ecm fuse for 10 seconds ...when using a timing light .
hope this helps

My timing light has advance and retard degrees, to see the mark on 0 degrees I'll need to advance my timing light, example, if the Astro's specs are 12 degree then I advance the timing to 12 and I'll see the crank at 0, so I am sure after removing the tan cable timing should not be zero, ty

[Sgt]

Actually after removing the wire it should be at zero. That is how they are set now (at least GMs). After reconnecting the wire, the "brain" will automatically advance the timing to the correct point. I was surprised too when I first learned this.

[no-one]

did you fix it turbo .....just curious

[TurboPirate]

Actually after removing the wire it should be at zero. That is how they are set now (at least GMs). After reconnecting the wire, the "brain" will automatically advance the timing to the correct point. I was surprised too when I first learned this.

The reason I ask because the astro is very week, and some times when you step on the gas to gain more power to get rid of a slow car or going UP hill just after you step on the gas some backfire comes out of the TBI not the exhaust.
This is what it has being done to the Astro.
New Cap and rotor
New sparks calibrated to specs
New sparks wire new coil. Just to be sure
New fuel filter
New air filter
I scanned the computer for codes non came UP
I told him it needs a thermostat because it is running way to cold ( this is what I believe its making it waste gas, very poor miles per gallon)
Told him a new coolant temp sensor because the one I saw its from factory and I know after a few years it gives wrong temp readings to computer (brain)
Told him new O2 sensor, it is also from factory and I am talking a 1986 Astro
I also notice the cable from transmission is to loose, you can step on the gas and it doesn't shift to stronger speed, it has to be done manually, the tranny is new is a 700R4, the same it came with but rebuilt.
Any suggestion besides the O2, Coolant temp sensor and thermostat? TY TURBO.

[Pollypurabred]

Thats pretty kewl, did not realize this. BUT since it did not work I assume you are having a different problem: vaccuum leak maybe; What I have seen on Oxy sensor is that it is either good or bad; I believe (not sure) but I'd look toward the air flow sensor if so equiped.

Let us know when solution is found....tks


Actually after removing the wire it should be at zero. That is how they are set now (at least GMs). After reconnecting the wire, the "brain" will automatically advance the timing to the correct point. I was surprised too when I first learned this.

[TurboPirate]

Thats pretty kewl, did not realize this. BUT since it did not work I assume you are having a different problem: vaccuum leak maybe; What I have seen on Oxy sensor is that it is either good or bad; I believe (not sure) but I'd look toward the air flow sensor if so equiped.

Let us know when solution is found....tks

I did a vacuum leak test and valve test to be sure no valves are stickie, Map sensor is working properly, O2 sensor with time they get so much of this black stuff that sends incorrect readings to ECM. When this happen you can see it in the live data stream of the diagnostic tool, instead of switching constantly between lean and rich, it stays more time to lean or rich, if it stays to long in lean you see black smoke coming out of exhaust pipe.

[TurboPirate]

Bump.... :bump:

[burnsy]

Sounds like you have a blocked catalytic converter Turbo

[TurboPirate]

Sounds like you have a blocked catalytic converter Turbo

I'll check that today burnsy, and will report back thanks...................

[TurboPirate]

Sounds like you have a blocked catalytic converter Turbo

I looked and looks new, I called the client and he said he forgot to mention that was the first thing he fixed when he bought the Astro, as I can see the catalytic is a direct fit from Pep Boys auto pats.

Thanks Burnsy, but this time that wasn't it, good call because I completely forgot those symptoms can be caused by a blocked Cat.

[burnsy]

Well if it only backfiring under load maybe the ECM is shot and is providing the fuel system with the incorrect fuel to air ratio or timing info how many Kim's on the van the 4.3 is notorious for poor fuel economy Having been with GM 35 years I can tell you it's a tough engine I have seen M vans with 500,000 Km's and still running strong

[TurboPirate]

Well if it only backfiring under load maybe the ECM is shot and is providing the fuel system with the incorrect fuel to air ratio or timing info how many Kim's on the van the 4.3 is notorious for poor fuel economy Having been with GM 35 years I can tell you it's a tough engine I have seen M vans with 500,000 Km's and still running strong

Thanks for the response, I got the ignition timing where it goes, reconnected the TAN cable, reset the ECM adjusted the tranny kick down wish I found verrrryyyy loose, and now no more back fire from TBI starts from a single turn of the key, up hills have the power I know those Astros have, now I will install the thermostat wish is not there the coolant temp sensor for correct readings and O2 sensor for also correct readings. It has 115,214 miles..........................I'll report.

[TurboPirate]

As of today, the Astro is running smooth but strong, no more mountain bikes passing us, lol, but UP hills is starting to make a noise I believe in English is called ping, because the fuel explodes before the spark occurs. I re check the timing removing the TAN cable and it is a 0 TDC, we are using premium gas 92 octane. any suggestions? TURBO.

[JCO]

It may be running lean... Pull a few plugs and check the color..

[TurboPirate]

It may be running lean... Pull a few plugs and check the color..

That is the Best X ray you can give to an engine, ty
I did check after you suggested and found out burning right color...............Gap is also checked.

[Terryl]

You say it's a used van, have you checked the Eeprom on the computer to see it it's been chipped?

Check with the dealer to see what version chip is in use for that series, I ran into an 85 that was chipped, ran good till it got to @38 MPH then it pinged like crazy, tried everything then found out the old owner had it chipped, got a stock one and it ran better, no pinging at low speeds, gas milage went down a bit but it ran as it should.

[hitest]

your scanner should give you your prom # and you can find the proper # that should be there as well ...at least my snapon scanner will ... here is a C/P from indentifix might help you it is not an astro but same engine

Vehicle Application: 1987 Chevrolet Caprice 4.3L, Vin Z, FI, Eng Cfg V6

Customer Concern: Engine pings at highway speeds under load. New converter, same. Different tanks of fuel tried, same.
Tests/Procedures: 1. Verify the heat riser valve mounted in the exhaust manifold for the exhaust crossover in the intake manifold is not stuck on.

2. Verify the air cleaner housing hot air vacuum motor is not stuck on.

3. Verify the ignition timing is set correctly.

4. Use a good quality top engine cleaner to remove carbon from the combustion chamber.

5. Verify the engine is not running lean.
Potential Causes: Air Cleaner Hot Air Door Motor
Engine Carbon
Heat Riser
Ignition Timing
Lean Running Condition

Diagnostic Codes: None
Tech Reported Fix Details Confirmed Fix

November 05, 2009 1987 Chevrolet Caprice, 4.3L, Vin Z, FI, Eng Cfg V6 *
Performed Valve Job — Removed excessive carbon from piston tops and the heads.
274,000 miles Valve Job

[TurboPirate]

You say it's a used van, have you checked the Eeprom on the computer to see it it's been chipped?

Check with the dealer to see what version chip is in use for that series, I ran into an 85 that was chipped, ran good till it got to @38 MPH then it pinged like crazy, tried everything then found out the old owner had it chipped, got a stock one and it ran better, no pinging at low speeds, gas milage went down a bit but it ran as it should.

It has the original #, is a new chip but its the correct replacement. The van is used, it runs great since I adjusted the timing, its UP hill where it pings.

[bigdummy]

Sure sounds like the timing chain is worn out and causing inconsistant timing on accel and decell due to the slack in the chain. ie your cam timing is late, adjusting the distributor will help compensate but will not correct condition completely.

[TurboPirate]

your scanner should give you your prom # and you can find the proper # that should be there as well ...at least my snapon scanner will ... here is a C/P from indentifix might help you it is not an astro but same engine

Vehicle Application: 1987 Chevrolet Caprice 4.3L, Vin Z, FI, Eng Cfg V6

Customer Concern: Engine pings at highway speeds under load. New converter, same. Different tanks of fuel tried, same.
Tests/Procedures: 1. Verify the heat riser valve mounted in the exhaust manifold for the exhaust crossover in the intake manifold is not stuck on.

2. Verify the air cleaner housing hot air vacuum motor is not stuck on.

3. Verify the ignition timing is set correctly.

4. Use a good quality top engine cleaner to remove carbon from the combustion chamber.

5. Verify the engine is not running lean.
Potential Causes: Air Cleaner Hot Air Door Motor
Engine Carbon
Heat Riser
Ignition Timing
Lean Running Condition

Diagnostic Codes: None
Tech Reported Fix Details Confirmed Fix

November 05, 2009 1987 Chevrolet Caprice, 4.3L, Vin Z, FI, Eng Cfg V6 *
Performed Valve Job — Removed excessive carbon from piston tops and the heads.
274,000 miles Valve Job

From 1 to 5 is all checked, I used OTC genesys, Snap ON scan tool, Sunpro, and Actron, they all gave me same readings, at idle the O2 stays to long at lean, also Temp is 174F wish I know is too low and found out thermostat was removed and not replaced.
About a Month a go the heads were removed and sent to machine shop, all 12 valves and steams were replaced, valve springs and retainers are new.

I set the timing with TAN cable disconnected to 0T then re connected the TAN cable and reset the ECM.

[hitest]

stupid question but you did make sure knock sensor is working and wasnt damaged when someone changed the starter.... and you have right sparkplugs ...heat range ...ngk ur5 . also you have had someone drive the van while your scanner is hooked up and watched all your live data while it was pinging to see if timing is stable or bouncing around as well as the rest of the data like o2s ... also just for the hell of it open the exhaust up before the cat and drive it just incase that newish cat maybe got melted some how ...

[TurboPirate]

stupid question but you did make sure knock sensor is working and wasnt damaged when someone changed the starter.... and you have right sparkplugs ...heat range ...ngk ur5 . also you have had someone drive the van while your scanner is hooked up and watched all your live data while it was pinging to see if timing is stable or bouncing around as well as the rest of the data like o2s ... also just for the hell of it open the exhaust up before the cat and drive it just incase that newish cat maybe got melted some how ...

The only stupid questions is the one question that was never asked, so your question is not stupid my friend, OK the Sparks are Rapid fire AC delco, specs for year model and engine, I will check the CAT like you mention in case it melted, it is not the first time I see a new CAT melt, I did used the Scanner wile my friend drove UP hill, the timing seems to adjust and Knock sensor wish is an ear registered the knocks EST also worked, O2 fluctuates very slow in my opinion, but I'll use the chemical to remove carbon built up from Piston tops.
Yes many home mechanics don't look and removing/ installing new starter brake the knock sensor, but I checked it and previous owner installed new one, is the only sensor I saw it was new and not from factory like the others were.
Thanks for the ideas, I'll report if CAT melted.

[TurboPirate]

Reporting, CAT is not melted, looks like new, it is new, lol, I re check the gap of each spark just in case I made a mistake but all under specs. I used the juice, that is how it is called the chemical to remove the carbon built UP from top of pistons, I removed the intake and checked each piston with with a tool for plumbing, lol I never knew there was a tiny camera with a light to see the inside of the house plumbing, he had this tool and saw the top of each piston and in my opinion they are clean enough, I could see the piston's metal.

Got to say, that tool helped me a lot and it was design for house plumbing not auto mechanics.

[hitest]

i have one to its called a borescope .. really cool ... good for checking interference engines when the timeing belt slips or breaks to see the pistons with bent valve marks in them ...customers love it ... and they are only $200 cdn.... now back to your problem sounds like youve pretty much checked everything so some how under a load the timing is advanceing to much take a good look at the distributor make sure advance springs are there and not broken and make sure its in correct not out a tooth or 180 and wires moved to match location ..... and it is a definate ping not a rattle or a knock... and assumeing it is a ping what happens if you backyard time it/ retard it until ping goes away do you loose to much power

[TurboPirate]

i have one to its called a borescope .. really cool ... good for checking interference engines when the timeing belt slips or breaks to see the pistons with bent valve marks in them ...customers love it ... and they are only $200 cdn.... now back to your problem sounds like youve pretty much checked everything so some how under a load the timing is advanceing to much take a good look at the distributor make sure advance springs are there and not broken and make sure its in correct not out a tooth or 180 and wires moved to match location ..... and it is a definate ping not a rattle or a knock... and assumeing it is a ping what happens if you backyard time it/ retard it until ping goes away do you loose to much power

Oh, now there is a problem, my first language is Spanish, not to good with technical words in English, I thought the correct translation was Ping, but let me explain, the sound it makes is the same one when you use cheap or old gasoline, or when the engine is so hot fuel ignites before the spark plugs sends a spark.
Today I re adjusted the kick down cable from tranny, last time I adjusted the engine gain power but in highways it was shifts into 4th and lockup way to early, now it shifts 4th and lockup like it should and very weird now UP hills is not pinging anymore.................