chevy lovin

87 tpi 305 70 k miles on it. runs real good. today for the heck of it i checked the timing with a timing light. the balancer mark is way to the left of the cover marks. i left it alone. what could be the deal with that. if it was that far advanced it would ping bad.as far as i know no mods were ever done to the cam. although it runs faster than my buddies stock 305 tpi of the same year. i smoke his.

bradley23150

iTrader: (10)

My motor does this too. When I put it in the proper timing, the engine shuts off and refuses to start. It doesnt make any sense to me. Though my motor isnt tpi.

Dunno.

racethesunlive

you disconnected the est wire too?

sparkplug619

you need to run the car in "service mode"(i think thats what its called) before setting the timing.. start up the car and stick a paper clip in ports a and b. (see below)




the car should idle lower, thats how you know its good to set the timing

IROCZ28KevinZ

iTrader: (2)

disconnecting the tan and black wire on the firewall disables the ECM's ability to advance/retard the timing so it can be properly set. if you didn't disconnect that wire before checking it, it was wherever the ECM had it advanced to.

renemedrano842

iTrader: (2)

so should you do both the paperclip and the black/tan wire? I've always just done the wire. Thanks.

sparkplug619

I think its either or.

wyochimneysweep

iTrader: (1)

its either or

chevy lovin

that sounds logical i got to find the tan and black wire. you guys are alot of help thanks.

JakeJr

It's located back near the power brake booster. A single tan wire with a black stripe.

A code gets set once the ECM detects the engine running with that wire disconnected, so you'll need to disconnect the battery for 30 seconds or so after your finished checking the timing then re-connect it.

While it's connected, the ECM takes over and controls the ignition timing. That's why your timing shows advanced. With the connector disconnected the timing should be 6 degrees BTDC if it's set to the stock setting.

Jake

chevy lovin

Jake Jr that was very helpful. if theres is problem il let you know. i was looking in the wrong place.

MyroccZ28

I have 5 various tpi 305 motors that ive pulled over the years. The one thing that was most common between them all was the harmonic balancer rubber ring was bad. It would allow the two pieces to move seperate as opposed to one. That wouldn't mess up your timing (engine wise) ,but would visually.... When the timing mark on the balancer is at 12 o'clock position, the crank keyway should also be at the 12 o'clock position. if it isn't your balancer is bad.... I hope that gets you into the right direction.

87IROC-DAN61

Hello Jake Jr!!

Isn't the EST Tan/Black stripe wire located on the passenger side, coming out of the wire harness conduit?? I have three thirdgens, two 1987 TPI's, and a 1989 TPI, and the EST wire is on the passenger side on all three, no where near the brake booster!!!

87IROC-DAN61

Hello sparkplug619!!

Read your underhood decal about checking/setting the timing, it says absolutely nothing about any paperclip in the ALDL connector!!

I've checked my timing plenty of times, and I've never had to put the car into "service mode" while checking/setting the timing!!

I call BS on this!!

87IROC-DAN61

Hello chevy lovin!!!

Read your underhood decal about how to check/set your timing, it tells you step by step, and it's your best source of info on how to do it!!

There is some erroneous info in this thread, and you could possibly damage your ECM using this erroneous info!!

Read the decal!!



P.S. If you don't have the underhood decal, let me know, and I'll post the contents of mine for you!!



P.P.S. To answer your original question, you must check the timing with the EST in "by-pass" mode (Tan/Black stripe wire disconnected at the connector) to get the correct reading off of the balancer!!!

sparkplug619

sparkplug619

HAHA ok great im going to throw away my service manual now because its filled with erroneous info. HAHA if only we were allowed to curse

87IROC-DAN61

Hello sparkplug619!!

Sometimes the wrong info is spread around, and then becomes "gospel", until someone calls B.S.

Check out the info on the underhood label on your car, it won't tell you to put anything in the ALDL connector while checking the timing, but it will give you the correct info on how to do it!!

87IROC-DAN61

Hello sparkplug619!!

What service manual is that???

sparkplug619

I completely understand that, I know theres no better instructions then the ones from the people who built the car but I was unaware of the sticker under my hood since my hood has been up against the wall since I bought the car.

It just pissed me off when you accused my info of being erroneous. I would never give advice unless the advice is confirmed. But I understand by you not knowing who I am and me being new to the forums, anyone would be iffy on my info so I am not angry with you and would also like to apologize for my anger in my previous posts.

sparkplug619

That would be chilton

sparkplug619

if you search for "aldl connector set timing" on google, plenty of info comes up for chevy cars, including info posted on thirdgen.org about using the aldl connector

87IROC-DAN61

Hello sparkplug619!!

I just checked my 1987 factory service manual, and a haynes manual that I have, and they both say to follow the underhood label!!

What year is your Chilton manual for??

Possibly a variance for a certain year??????? Prior to 1987???

87IROC-DAN61

Hello sparkplug619!!

I'll check it out!!

sparkplug619

Ok I read a little closer into the book and have to apologize.

it says from 88-90 to use the aldl and from 82-87 and 91-92 use the sticker under the hood.

sorry buddy I should've read closer. I am working with an 89 and have been grounding the aldl to put my car in service to check the codes before I pulled the engine and the idle would definitely drop when I connected it

87IROC-DAN61

Hello sparkplug619!!

I checked out a thread in the TBI forum, under How to set timing on TBI, and someone there mentions your method, and that it didn't work, and that you disconnect the Tan/Black Stripe wire regardless which FI system you have!!

This person also quotes the Chiltons manual........he also asks if the Chiltons manual is wrong!!

Your not convincing me yet, that your method works!!!!

87IROC-DAN61

Hello sparkplug619!!

I have a 1989 TPI sitting in my driveway, and the underhood label still doesn't say anything of the sort, it tells me to disconnect the Tan/Black stripe wire to put the EST into "by-pass" mode!!

sparkplug619

OK you dont have to believe me or chilton. Im just stating what I read and posted my evidence. the book says ground the aldl and the car says pull the wire. I believe both of them but that doesnt mean you have to. you say your not convinced well I am not here to convince you, I stated the fact and backed it up with evidence, theres nothing left to do so do your thing .

sparkplug619

What I am trying to tell you is that there is a different method from what the sticker says. The book states a different method, if its been published then it must work. Im not telling you "do not to pull the connector", just to basically think outside the box

87IROC-DAN61

Hello sparkplug619!!

This all started because of a difference of methods, you posted your stuff, and I posted my stuff, I'm willing to accept a different approach to a common solution, and maybe your method is a short cut to my method!!

Does that make sense to you????

My last post was a question to you, I guess I could have "posed" it another way!! Does it work for you on your 1989 when you jumper the A-B terminal???

I ask this because I have a 1989 also, maybe I'll try your method????

The end result here is not to leave in a huff, but to leave with more knowledge, as that's what these boards are supposed to do!!





P.S. Have a good night!!

87IROC-DAN61

Hello sparkplug619!!

Read my last post, you'll understand that I did think outside the box!!

By stating that I may try your method!!

sparkplug619

I'm not trying to leave angry but from your post it seemed as if I am supposed to sell it to you. So I would rather leave with "take it or leave it" instead of argueing about something I know will work (the "pull the wire" method) versus something that was published stating it will work. I never seen the sticker so I posted the method I found in a published book.

87IROC-DAN61

Hello sparkplug619!!

I used the "convinced" word because at that point it was, (by your own admission erroneous info, due to the years), but I was willing to accept it if you could give me some validation!! (thinking outside the box)

Sometimes posts get missed in the, back and forth banter, until after you go back and read them again!!

Published stuff has been known to have errors in them also, so when you told me to check out the info on Google, I did, and then it too told me that the jumpered A-B terminal was wrong, which validated to me that your info was wrong!!

I'm willing to accept things being different, but I need the validation that it is in fact good info!!

johnny89345

you do realize old *** balancers spin over the years and become way off from where they should be thats why you never trust the balancer mark when installing a new distributor

sparkplug619

FWIW, I used to own a toyota supra and toyota celica a while back and I would use the diagnostics terminal (jumper te1 to e1) to set the timing. I know toyota is a completely different car but they are all OBD-I.

Same with the engine codes, jumper the diagnostics for the 'check engine' light to blink

johnny89345

i guarantee either your balancer spun or your off a tooth or so on the distributor. you know what your advance on the dizzy could also be bad. try this hold a set rpm and see if the timing jumps around or stays consitent. not trying to be a dick but do not try timing your car with jumping the terminals

sparkplug619

Hey there. I'm not the one with the timing issues if your referring to me.

Also notrying to be a Dick but you guys can believe the diagnostics jumper trick doesn't work but I do and i give up feeding the evidence to support the idea. I know it works because I've been doing it in obd-i systems for years. If you guys dont want to accept that it works then that is fine with me. Until someone can prove it the ecu still advances the timing or it damages the obd-I system then i will stick by this idea.

There are more technologically advanced obd-i engines I have worked on That require terminal jumping to set timing. And this info is not from a haynes or chilton but from the factory service manual.

Thank you

88gta_hiflyer

iTrader: (1)

hey chevy lovin,

Did you ever get your timing issue figured out? My timing mark on the balancer is also way to the left of the cover marks. I set my base timing at exactly 6* with the est wire disconnected. However, as soon as I reconnect it the timing goes way back to the left.

Does anyone know if this is normal while the ECM is contolling spark advance? If not, what would cause this? The car starts and runs fine but this seems strange to me.

chevy lovin

exactly what mine did. still runs like a monster

87IROC-DAN61

Hello 88gta_hiflyer!!

That's why the underhood label tells you to disconnect the tan/black stripe wire, so that you can get a proper reading for the timing mark, as opposed to a false reading while the EST is functioning!!



Try timing your motor with the tan/black stripe wire connected, doesn't work too good!!



In otherwords, the timing mark "looks" to move to the left with the EST connected, but it's normal, just always set/check the timing with the tan/black stripe wire disconnected, you can't go wrong!!

88gta_hiflyer

iTrader: (1)

Hey 87IROC-DAN,

Thanks for the reply. As I stated above, I set the BASE timing at 6* as per the label under the hood. So yes, with the EST wire disconnected. I just wasn't sure if the timing should change that drastically from the base setting at idle. I didn't remeber it doing that before I replaced my ignition module which is why I was curious. Just wanted to make sure I didn't have another problem. Thanks for the input!

88formula305tpi

I tryed setting my timing yesterday and had the tan black wire unplugged. car was warmed up, but the weird thing was the timing would still go back and forth from 20's to 6 back and forth and then stall after trying to run at 6 for a while.

What would cause timing to still advance? I also have an erratic tach problem on hot days im trying to figure out.

88formula305tpi

ok the engine idles high after started with est bypassed timing in 20's
then rpms drop to idle and timing remains at 6
it will go back and forth in rpms staying at idle shorter every time untill it finally dies.

do i need to advance it more to 10 degrees?

As for the erratic tach i tryed reinstalling my old coil no difference, then I installed my old ignition module and that made no difference other than a long crank and code 42.

87IROC-DAN61

Hello sparkplug619!!

I bought a factory service manual for my 1989 Camaro IROC-Z, and you won't guess what I found in the manual!!!

It says to check the timing, follow the underhood label, however, if the label is unavailable, ground terminal A - B on the ALDL!!

I take back the that I called on you!!!

One advantage of this way, is that it doesn't set a code 42, if done properly!!