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Fun time today! Sudden rough running and check engine light by ArthurPeale
Started on: 09-05-2021 06:26 PM
Replies: 13 (183 views)
Last post by: ArthurPeale on 09-13-2021 09:40 AM
ArthurPeale
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Report this Post09-05-2021 06:26 PM Click Here to See the Profile for ArthurPealeClick Here to Email ArthurPealeSend a Private Message to ArthurPealeEdit/Delete MessageReply w/QuoteDirect Link to This Post
1986 SE v6 2.8

I shifted into reverse earlier and it was running really rough, and the Check Engine light came on. Shifted into neutral and it shut off. Shifted back into reverse and it was fine.

I'd like to know what happened.

Jumpered the ALDL - code 33. Huh.

I just discovered a few things....

1) the recall for the pipe along the firewall was never done on this vehicle. Huh.

2) the front manifold is glowing a bit. It's never done that before now, that I'm aware.

3) for giggles, since I already had the paperclip in the ALDL, I tried to start it - it wouldn't. Fired right up as soon as I removed it, and ran like a top. Ran like CRAP if I put it back.
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IMSA GT
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Report this Post09-05-2021 07:11 PM Click Here to See the Profile for IMSA GTClick Here to Email IMSA GTSend a Private Message to IMSA GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sounds like the MAP sensor died.
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ArthurPeale
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Report this Post09-05-2021 07:17 PM Click Here to See the Profile for ArthurPealeClick Here to Email ArthurPealeSend a Private Message to ArthurPealeEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by IMSA GT:

Sounds like the MAP sensor died.


Maybe. It recovered within seconds, and is still running like a top.

I thought it was uncommon for them to die?
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Patrick
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Report this Post09-06-2021 02:26 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ArthurPeale:

I just discovered a few things....

1) the recall for the pipe along the firewall was never done on this vehicle. Huh.



Why, what exactly did you find (or not find)? Post a photo.

 
quote
Originally posted by ArthurPeale:

...for giggles, since I already had the paperclip in the ALDL, I tried to start it - it wouldn't. Fired right up as soon as I removed it, and ran like a top. Ran like CRAP if I put it back.


Although your engine may appear to be running "like a top", that's very much a subjective observation. If the engine won't start with the ALDL jumper in place (which effectively retards the timing), something's not right.

Of course I don't know for sure, but it sounds to me like the ignition timing is set too retarded (or it was originally set correctly, but the clamp has loosened and the distributor has moved a bit). If a timing light were to show otherwise, I'd suspect the outer ring of the harmonic balancer has slipped, and the timing grooves on the balancer are no longer in the right place (in relation to the crankshaft).

[This message has been edited by Patrick (edited 09-06-2021).]

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ArthurPeale
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Report this Post09-06-2021 01:44 PM Click Here to See the Profile for ArthurPealeClick Here to Email ArthurPealeSend a Private Message to ArthurPealeEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

Why, what exactly did you find (or not find)? Post a photo.


It'll have to be later, but the line that goes from the air cleaner housing to the valve cover against the firewall, it's intact.


 
quote
Originally posted by Patrick:
Although your engine may appear to be running "like a top", that's very much a subjective observation. If the engine won't start with the ALDL jumper in place (which effectively retards the timing), something's not right.

Of course I don't know for sure, but it sounds to me like the ignition timing is set too retarded (or it was originally set correctly, but the clamp has loosened and the distributor has moved a bit). If a timing light were to show otherwise, I'd suspect the outer ring of the harmonic balancer has slipped, and the timing grooves on the balancer are no longer in the right place (in relation to the crankshaft).



It started once I removed the paper clip, then once put back, it would run poorly. Agreed that I'll have to do some investigating, this was just a prelim.
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Xenoblast
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Report this Post09-06-2021 03:17 PM Click Here to See the Profile for XenoblastClick Here to Email XenoblastSend a Private Message to XenoblastEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:


Of course I don't know for sure, but it sounds to me like the ignition timing is set too retarded



I second this. My engine used to be 30 degrees retarded when i first got it, and it didnt feel any different then it does now except maybe some more torque on the low end. I only checked it out of curiousity. And my headers did glow red after only 2-3 minutes of running in diag mode.

It didnt idle on its own in diag mode, so i had a friend keep on the gas while i turned the distributer until it idled on its own. I then had him help me set it more precisely.

the reason why i know it was 30 degrees retarded is because it showed 10 degrees of timing out of diag mode, so the previous owner must of skipped grounding the connector

[This message has been edited by Xenoblast (edited 09-06-2021).]

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Patrick
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Report this Post09-06-2021 05:42 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ArthurPeale:

...the line that goes from the air cleaner housing to the valve cover against the firewall, it's intact.


Well, that's fine. However, if the open end of that tube hasn't been capped off, then that's not fine.

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ArthurPeale
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Report this Post09-07-2021 05:00 PM Click Here to See the Profile for ArthurPealeClick Here to Email ArthurPealeSend a Private Message to ArthurPealeEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

Well, that's fine. However, if the open end of that tube hasn't been capped off, then that's not fine.


the tube isn't open ended; it goes directly from the air cleaner housing to the valve cover.

I'll see about snapping some photos soon. It's been a rough few days.

Interesting note: the gasket between the deck lid and rear window is still there.
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Report this Post09-07-2021 05:15 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ArthurPeale:

the tube isn't open ended; it goes directly from the air cleaner housing to the valve cover.

Interesting note: the gasket between the deck lid and rear window is still there.



Sounds like your Fiero has never had the recall done to it. Rather unusual.

Does your engine then not have this newer style breather tube connected on the front side of your engine? (The end not connected in the photo plugs into a replacement snorkel).

[This message has been edited by Patrick (edited 09-07-2021).]

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ArthurPeale
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Report this Post09-08-2021 10:48 AM Click Here to See the Profile for ArthurPealeClick Here to Email ArthurPealeSend a Private Message to ArthurPealeEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

Sounds like your Fiero has never had the recall done to it. Rather unusual.


 
quote
Originally posted by ArthurPeale:

I just discovered a few things....

1) the recall for the pipe along the firewall was never done on this vehicle. Huh.


 
quote
Originally posted by Patrick:Does your engine then not have this newer style breather tube connected on the front side of your engine? (The end not connected in the photo plugs into a replacement snorkel).





Pretty sure not. I'll have to look.

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ArthurPeale
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Report this Post09-12-2021 05:26 PM Click Here to See the Profile for ArthurPealeClick Here to Email ArthurPealeSend a Private Message to ArthurPealeEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Xenoblast:


I second this. My engine used to be 30 degrees retarded when i first got it, and it didn't feel any different then it does now except maybe some more torque on the low end. I only checked it out of curiosity. And my headers did glow red after only 2-3 minutes of running in diag mode.

It didn't idle on its own in diag mode, so i had a friend keep on the gas while i turned the distributor until it idled on its own. I then had him help me set it more precisely.

the reason why i know it was 30 degrees retarded is because it showed 10 degrees of timing out of diag mode, so the previous owner must of skipped grounding the connector



Luckily, I picked up a timing light last summer. Yard sale find, five bucks.

WITHOUT the paperclip in place, it was reading ~10 degrees. WITH it in place...I couldn't even see the line, at all.

No wonder it was running like garbage with the paperclip in place.

I'm just amazed that the computer was able to compensate for things being so far off.

After I pulled the paper clip, it was COMPLETE GARBAGE, of course - the computer had old values to deal with.

Pulled the battery cable for a bit, went for a drive...I'll have to continue to play with the timing.

At one point I'd turned the distributor just right so when I hit the key she was sitting there, purring like a kitten. I've never heard her run so good.

Put, since the mark wasn't on 10, I decided to keep messing with it. That was a mistake, it was running poorly.

I finally got it to a point where I'm...happy-ish. I need a second to be able to keep the RPM at 2000
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Report this Post09-12-2021 08:28 PM Click Here to See the Profile for SkybaxSend a Private Message to SkybaxEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ArthurPeale:

the tube isn't open ended; it goes directly from the air cleaner housing to the valve cover.

Interesting note: the gasket between the deck lid and rear window is still there.


That is a good thing. Most people don't realize the majority of the recall "mods" were detrimental on the V6. The most important recall you want to make sure was performed is the rubber splash guards are trimmed at the forward position of the rear wheel wells where the lower rad hoses connect to the coolant pipes. You want to make sure those splash guards are not rubbing on the rad hoses because it could wear a hole in them.

As far as the seal on the deck lid at the rear window, be glad the recall was never done, because that saved your forward exhaust manifold from cracking from cold water on hot manifold over a period of decades (also prevents leaves from falling down onto exhaust manifold between deck lid and rear window). The safety concern at the time was the seal could fall down and touch manifold, so just make sure it is secure and doesn't fall down. Mine has been on there for 36 years, still secure, rubber still flexible, and still doing the job it was designed to do. Many people nowadays put the seal back on because the benefits outweigh the risks.

Additionally, many of these recalls done back in the day were preformed quickly at dealer by hacks who didn't take the time for quality workmanship, so lots of V6 Fiero owners had their nice car molested with broken exhaust studs and other collateral damage to add the shield to the forward manifold which is not needed. All you need to do is monitor your engine for leaks, if the rear valve cover gasket starts leaking, replace it, that's all. Same goes for the breather tube, if you have a nice running engine with no blow-by and no oil is air cleaner, then no problem.

[This message has been edited by Skybax (edited 09-12-2021).]

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Patrick
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Report this Post09-13-2021 01:13 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ArthurPeale:

At one point I'd turned the distributor just right so when I hit the key she was sitting there, purring like a kitten. I've never heard her run so good.


But you previously said she "ran like a top".

Sounds like you're now on the right track.

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ArthurPeale
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Report this Post09-13-2021 09:40 AM Click Here to See the Profile for ArthurPealeClick Here to Email ArthurPealeSend a Private Message to ArthurPealeEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

But you previously said she "ran like a top".

Sounds like you're now on the right track.


I'm just amazed how much the computer had to have been compensating for it being so far off. I stand by what I said - it's just so much better in spec. I wish I'd had a clue all of these months.

Took her for the longest drive I've done yet, yesterday, a 40 mile trip to get ice cream, back and forth. No fuss, no muss!
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