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Stock V6 stall and rough idle by Alblindi
Started on: 03-11-2014 12:49 AM
Replies: 6 (472 views)
Last post by: Alblindi on 03-12-2014 12:17 AM
Alblindi
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Report this Post03-11-2014 12:49 AM Click Here to See the Profile for AlblindiSend a Private Message to AlblindiEdit/Delete MessageReply w/QuoteDirect Link to This Post
I had mentioned this in a post I have in the General Fiero Chat sub-forum, but I figured I'd bring it here as well since this would technically be the appropriate place to bring it up.

I just got an 88 Formula about a month ago. When I've been driving it for a while, particularly at speed (~60 mph) for half an hour or more, if I stop it too suddenly, it stalls. I have a hard time putting it into gear again without it continuing to stall out. I've ended up having to open up the throttle while shifting it into gear, which jerked the car very hard. I hope I didn't damage the transmission any... Also, it seems to idle roughly. I don't know if the fuel line pressure is low, or maybe it doesn't have an effective ground, or if it's not cooling down efficiently enough. The brand new fuel pump also tends to make a whirring noise, which has died down over the past few days. I put some fuel additive/injector cleaner into the fuel hoping it would increase the flow of fuel from the tank to the engine one way or another. I don't know if this has helped the fuel pump any, because I mentioned the symptoms to my dad and he said it sounded like cavitation.

The reason I'd believe that it's the fuel supply though is because the shop said they had to put a more powerful pump on the car than was originally designed. Apparently it wasn't moving enough gas to the engine; it used to not idle at all. They cleaned out the whole fuel injection system except for the injectors themselves; I reckon the next step would be to replace those. I heard there's a mesh on the fuel tank that could clog up if it sits for too long and gunk gets in there. Something tells me they re-used the original one, so I'll mention that to them as well.

I know that was a lot of information to fit into two paragraphs, but any help would be appreciated.

I've heard a suggestion that it could be the Torque Converter Clutch Solenoid, so I'll take a look at that the next chance I get.
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phonedawgz
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Report this Post03-11-2014 06:27 AM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Alblindi:

The brand new fuel pump also tends to make a whirring noise, which has died down over the past few days.


They all do that

 
quote
cavitation


nope

 
quote
The reason I'd believe that it's the fuel supply though is because the shop said they had to put a more powerful pump on the car than was originally designed. Apparently it wasn't moving enough gas to the engine; it used to not idle at all. They cleaned out the whole fuel injection system except for the injectors themselves; I reckon the next step would be to replace those. I heard there's a mesh on the fuel tank that could clog up if it sits for too long and gunk gets in there. Something tells me they re-used the original one, so I'll mention that to them as well.


You shop is feeding you BS. If they put on a more powerful pump, they did it because that was the one they could get a hold of.

A $19.95 Harbor Freight fuel injection fuel pressure meter can tell you if you have the 42 approx PSI fuel pressure you are supposed to have. Using tools to troubleshoot works much better than using guesses.

42 PSI key on engine off - right after the 2 second "prime" event where the ECM runs the fuel pump. 42 psi - manifold vacuum when the engine is running.

Have the spark plugs been replaced? Including the front three spark plugs? Look for yourself using a mirror on a cold engine. Don't swap the plug wires when inspecting the front plugs. Many times people only replace the rear plugs since they are easier to get to.

This problem doesn't sound like a fuel supply problem.

[This message has been edited by phonedawgz (edited 03-11-2014).]

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Gall757
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Report this Post03-11-2014 08:00 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Your injectors are probably good, but still dirty. When I got my Formula, it would not idle well. I tried two bottles of injector cleaner (with a little success) and took it to a shop that ran a stronger cleaner through the fuel rail 2 more times. It finally worked. You can also remove them and have the injectors cleaned and tested.
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Marvin McInnis
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Report this Post03-11-2014 02:04 PM Click Here to See the Profile for Marvin McInnisClick Here to visit Marvin McInnis's HomePageSend a Private Message to Marvin McInnisEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Alblindi:

I just got an 88 Formula about a month ago. When I've been driving it for a while, particularly at speed (~60 mph) for half an hour or more, if I stop it too suddenly, it stalls. I have a hard time putting it into gear again without it continuing to stall out. I've ended up having to open up the throttle while shifting it into gear, which jerked the car very hard.
...
I've heard a suggestion that it could be the Torque Converter Clutch Solenoid, so I'll take a look at that the next chance I get.



Assuming your car is an automatic, the TCC solenoid is your problem. Replace the third-gear switch while you're at it. There is lots of information on replacing the TCC solenoid in the PFF archives. The parts required (TCC solenoid, 3rd gear switch, and end-cover gasket) should be less than $50 total.


 
quote

... the shop said they had to put a more powerful pump on the car than was originally designed. Apparently it wasn't moving enough gas to the engine ...



Pure bulldust! Based on that, it sounds like you need to find a new, more competent, and more honest shop if you're not doing the work yourself.

[This message has been edited by Marvin McInnis (edited 03-11-2014).]

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Alblindi
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Report this Post03-11-2014 05:27 PM Click Here to See the Profile for AlblindiSend a Private Message to AlblindiEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thank you all for the responses. I do have an Auto Tranny, and disconnecting the TCC Solenoid has solved the stalling problem. It still idles roughly, but I suppose I'll just have to work that out over time. Will I just have to replace the solenoid, or is there possibly more at stake here?

I'd also like to add that the people I deal with, Mr. Greg Holder and his assistant Jeff, have always been completely honest with me, and I wouldn't suspect them of doing me wrong. We're actually good friends outside of the shop. They haven't worked much with Fieros, so they're probably unfamiliar with their unique and relatively complicated system. Also, the information that they had to put on a more powerful pump was relayed to me by my dad, so I may have heard him incorrectly.

I plan on driving down to The Fiero Factory on Thursday morning (it's only a 2 hour drive for me), and they'll be able to look at things a little more thoroughly.

[This message has been edited by Alblindi (edited 03-11-2014).]

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Jefrysuko
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Report this Post03-11-2014 10:14 PM Click Here to See the Profile for JefrysukoSend a Private Message to JefrysukoEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Alblindi:

Thank you all for the responses. I do have an Auto Tranny, and disconnecting the TCC Solenoid has solved the stalling problem.



I told you so! Seriously though, good for you taking the info we provided to you and getting your hands a little dirty to do your own analysis of the problem.

It get's a little old sometimes when younger members show up here, disregard good advice and refuse to help themselves. Glad to see you're not in that camp!

 
quote
Originally posted by Alblindi:

I plan on driving down to The Fiero Factory on Thursday morning (it's only a 2 hour drive for me), and they'll be able to look at things a little more thoroughly.



You'll be in good hands with those guys!
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Alblindi
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Report this Post03-12-2014 12:17 AM Click Here to See the Profile for AlblindiSend a Private Message to AlblindiEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
I told you so! Seriously though, good for you taking the info we provided to you and getting your hands a little dirty to do your own analysis of the problem.

It get's a little old sometimes when younger members show up here, disregard good advice and refuse to help themselves. Glad to see you're not in that camp!


Oh, I'll be the first to admit that I'd have no clue what I'm doing otherwise. Unlike the stereotypical snobby teenager, I can recognize a great opportunity when I see one, and this forum is absolutely amazing when it comes to advice. I mean, it's not like you see an Accord forum like this, do ya now?

On a side note, I called Jeremy Biggs, the owner of TFF, and he said that they no longer carry their famous decarbonizing kit. Bummer. I really am looking forward to visiting them, though; even if they can't get to all the things on my car, granted how busy they must be, it'll still be an experience. I consider myself almost blessed that I live just two hours north.
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