2.8 EST connector
2.8 EST connector
Hi Gang,
I am not new to this but I feel stupid having to ask this: Where is the EST connector on my '88 2.8L Camaro? I only found one wire that even looked close but it made no difference when I unplugged it. I assume it is buried pretty well but perhaps someone could point me in the right direction?
[This message has been edited by transfixleo (edited October 21, 2001).]
I am not new to this but I feel stupid having to ask this: Where is the EST connector on my '88 2.8L Camaro? I only found one wire that even looked close but it made no difference when I unplugged it. I assume it is buried pretty well but perhaps someone could point me in the right direction?
[This message has been edited by transfixleo (edited October 21, 2001).]
Trans,
The procedure for timing adjustment on the 173 CI MPFI engine is different than that used for the V-8s. There is no dedicated EST bypass connector. Check the VECI label under the hood for instructions.
The VECI label is the most important label on you car (from a service perspective), and it should tell you that you need to block the drive wheels and set the park brake, start the engine and allow it to reach normal operating temperature, verify that there is no "Check Engine" light, jumper the diagnostic request terminal on the ALDL (Terminals A to B), and check/adjust the timing. You should check the timing on both the #1 and #4 cylinders, and use the average timing of the two as you base line. Removing the jumper will return timing control to the ECM.
Remember that it is important to have the engine running BEFORE you install the jumper, and that you should not attempt to crank or start the engine with the jumper in place.
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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
The procedure for timing adjustment on the 173 CI MPFI engine is different than that used for the V-8s. There is no dedicated EST bypass connector. Check the VECI label under the hood for instructions.
The VECI label is the most important label on you car (from a service perspective), and it should tell you that you need to block the drive wheels and set the park brake, start the engine and allow it to reach normal operating temperature, verify that there is no "Check Engine" light, jumper the diagnostic request terminal on the ALDL (Terminals A to B), and check/adjust the timing. You should check the timing on both the #1 and #4 cylinders, and use the average timing of the two as you base line. Removing the jumper will return timing control to the ECM.
Remember that it is important to have the engine running BEFORE you install the jumper, and that you should not attempt to crank or start the engine with the jumper in place.
------------------
Later,
Vader
------------------
If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
On the underhood tag it does tell me to unplug the single wire connector but not the four wire connector. Trouble is I haven't been able to identify it. I am a former GM dealer tech (Buick) so ia have experience with this but we didn't use tis engine. I spend 99.9% of my time on trannies now so I am really out of the loop on this.
Trans,
Just so we're all on the same page here, I understand this is an '88 Camaro, with the 173 V-6. This IS an MPFI, right? Or is it a carbed/TBI engine?
Is this the original engine? The manuals I have show either the ALDL grounding or disconnection of the four-wire weatherpak connector at the distributor. Tha only engines that have the single EST bypass connector are supposed to be the V-8s, but I've found erroneous information in manuals before. (¿?)
------------------
Later,
Vader
------------------
If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
Just so we're all on the same page here, I understand this is an '88 Camaro, with the 173 V-6. This IS an MPFI, right? Or is it a carbed/TBI engine?
Is this the original engine? The manuals I have show either the ALDL grounding or disconnection of the four-wire weatherpak connector at the distributor. Tha only engines that have the single EST bypass connector are supposed to be the V-8s, but I've found erroneous information in manuals before. (¿?)
------------------
Later,
Vader
------------------
If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
Yes it is the 2.8 MPFI and it is the original 137K engine. I have a manual that says on the '89 that you ground the ALDL but the tag under the hood says to disconnect the EST wire. Not that the General would ever make a mistake! I did have the connector grounded and still showed advanced timing so it didn't disable it and it runs pretty good now so I now it's not too far off (hense the fact that I am just getting around to checking the timing after a year of owning it [he said sheepishly]).
[This message has been edited by transfixleo (edited October 21, 2001).]
[This message has been edited by transfixleo (edited October 21, 2001).]
Vader, I can vouche for him, my sticker says to disconnect the EST connector as well, and no, we never found it... (neither did grounding out the terminal)
Althought recently I did come across a single wire connector on the pass side just behind the strut tower, you might wanna try that..
I just advance mine till it knocks, then back it off...
If it knocks in the morning when it's cold, back it off till it doesn't and the timing is set perfectly...
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1985 Camaro SC - 2.8L, auto.
C'mon, spin 'em for papa...
http://www.xenodrgn.f2s.com/Frontright.jpg
Althought recently I did come across a single wire connector on the pass side just behind the strut tower, you might wanna try that..
I just advance mine till it knocks, then back it off...
If it knocks in the morning when it's cold, back it off till it doesn't and the timing is set perfectly...
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1985 Camaro SC - 2.8L, auto.
C'mon, spin 'em for papa...
http://www.xenodrgn.f2s.com/Frontright.jpg
Mine says to disconnect the EST which is a single Tan wire with a Black stripe. It's located between the A/C accumulator and the strut tower. Just follow the main wire harness and you will see a single wire and connector that branches out of the main wire harness.
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-Dan
-1990 3.1L RS
-Mods? no
-Slow? yes
-Currently collecting parts for T5 swap
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-Dan
-1990 3.1L RS
-Mods? no
-Slow? yes
-Currently collecting parts for T5 swap

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OK cali, yep, thats the one that I found... thanks for confirming.
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1985 Camaro SC - 2.8L, auto.
C'mon, spin 'em for papa...
http://www.xenodrgn.f2s.com/Frontright.jpg
------------------
1985 Camaro SC - 2.8L, auto.
C'mon, spin 'em for papa...
http://www.xenodrgn.f2s.com/Frontright.jpg
I gave my car to my kid to drive while I fix his car so I can't check it now. For what it is worth, my car doesn't have A/C but I assume you mean by the passenger side strut? If not, let me know. I found a grey connector that actually goes into the coil but it didn't look like the normal sealed connector I am used to. It didn't make any difference anyways.
I hope this might clear things up a little.
The arrow points to the EST on my 86 2.8L Bird.
The pic is not very good but it is the only slide I had of the engine bay.
Just separate the connector, move the dist to set timing, plug it back together, clear the code from the computer and go.
Dale
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1986 FireBird
2.8L MPFI
1/2 CAI
Gutted Cat, No muffler
Was 700-R4 --> Now T5
**** Great cars aren't bought, they're built ****
[This message has been edited by 86Chicken (edited October 21, 2001).]
The arrow points to the EST on my 86 2.8L Bird.
The pic is not very good but it is the only slide I had of the engine bay.
Just separate the connector, move the dist to set timing, plug it back together, clear the code from the computer and go.
Dale
------------------
1986 FireBird
2.8L MPFI
1/2 CAI
Gutted Cat, No muffler
Was 700-R4 --> Now T5
**** Great cars aren't bought, they're built ****
[This message has been edited by 86Chicken (edited October 21, 2001).]
<font face="Verdana, Arial" size="2">Originally posted by 86Chicken:
I hope this might clear things up a little.
The arrow points to the EST on my 86 2.8L Bird.
The pic is not very good but it is the only slide I had of the engine bay.
Just separate the connector, move the dist to set timing, plug it back together, clear the code from the computer and go.
Dale
</font>
I hope this might clear things up a little.
The arrow points to the EST on my 86 2.8L Bird.
The pic is not very good but it is the only slide I had of the engine bay.
Just separate the connector, move the dist to set timing, plug it back together, clear the code from the computer and go.
Dale
</font>
Well, I'll be a dim-witted FIB! My manuals say that only the V-8s have the EST bypass connector (until 1992). So much for the value of a "good" manual. That's why I said the VECI label is generally the most important reference - they are usually right.
This photo might show it a little more clearly - the red background is a little better for contrast:
BTW - Get any snow that has STUCK yet? I was in Hayward last weekend and got flurries both nights. Just a dusting, but promising, at least. I can smell the Castrol now...

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Later,
Vader
------------------
If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
Last edited by Vader; Mar 31, 2018 at 10:34 AM. Reason: Updated links
Vader:
FIB!?!
Anyway, I am pretty sure my '86 GM Service manual mentions the connector for the V6 but the Haynes book does not (big surprise). I could be wrong tho.
No snow on the ground yet but it will be very soon. Just pulled in the pier this weekend so I am ready for winter.
Dale
FIB!?!
Anyway, I am pretty sure my '86 GM Service manual mentions the connector for the V6 but the Haynes book does not (big surprise). I could be wrong tho.No snow on the ground yet but it will be very soon. Just pulled in the pier this weekend so I am ready for winter.
Dale
Thanks for the help! I finally got my car back and I took a look for the EST connector. Sure ehough, it was tucked right under the lip of the firewall, above the harness. I checked the timing and it was right on the money at 10 degrees. I wanted to try moving it up a little but now I have to find the right tool for getting under the distributor but clear of the connectors! It's always something.
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