Pennock's Fiero Forum
  Technical Discussion & Questions
  Stock 88 GT still not running right, any more suggestions?

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
Stock 88 GT still not running right, any more suggestions? by st88fiero
Started on: 08-10-2013 07:40 AM
Replies: 10 (281 views)
Last post by: st88fiero on 10-06-2013 10:16 AM
st88fiero
Member
Posts: 43
From: Long Island, NY
Registered: Jul 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post08-10-2013 07:40 AM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
I had posted this last night under different topic Subjct. i am hoping to get some ideas, would like to work on this weekend:


From my original post from two weeks ago:

When I first got the car back home it was running very rough and had a miss, possibly two cylinders not firing, running very rich and would stall and had no power at all.

I had the cap, rotor, plugs and wires changed. According to my mechanic, he believes that they were all original parts, two of the back plugs were quite rusty, along with wires, and the plugs themselves were fouled out, very wet from running rich.

The car had an marked improvement as soon as we changed those parts, (the miss was all but gone, but slightly rough at lower RPM's) and was still having a bit of an issue holding idle, it seemed to be a bit high when first starting, then as car warmed up it would seem to be hunting around trying to find idle - while driving and occasionally stalling upon depressing of clutch. If you turned the AC at all the car would just die and the running rich condition was still a factor

We changed IAC which at first seemed to help but then the car did stall a few times.

I chalked it up to bad gas and threw in Cheveron fuel injector cleaner and some Premium gas and hit the road. After about 10 miles of driving the car began to find it's idle and was not stalling and you could actually turn the AC on without it dying.(still robs the power from the engine).
   


So it has now been three days of driving car around locally and i say it's 80% running right, but I still have a rich running condition and the car has the slightest roughness in lower RPM range (around 1500-2700 range), as soon as you are through that it runs very smooth all the way up to red line, the car on the parkway runs perfect and will go along at 90 MPH without any issue what so ever, but the lower end in just not right. Car still seems to idle a bit rough and it "choppy" as you first start to roll, not bad just not right.


Form my post last night:

Well as I type this is sit here stumped and so is my mechanic. He has checked all possible items that we think it could be. On top of what was previously stated, he has confirmed that the EGR, o2, all temp. sensors are reading correctly, has scanned the computer for any possible codes, ran a commercial upper intake cleaner through the system, checked timing, did the basic fuel pressure test, they are holding steady at 40lbs.
At this point I am afraid to say it must be something internal on the engine. I would assume that it is mostly likely a collapsed lifter, but it is so strange that it is making absolutely no noise at all, but the poor running condition persists and i have to figure out why?

If if is a bad lifter I assume a compression test needs to be done to verify. How the heck do you get to the back cylinders to make that happen?

Any additional thoughts from the crowd?....I am determined to fix this thing!

[This message has been edited by st88fiero (edited 08-10-2013).]

IP: Logged
PFF
System Bot
Gall757
Member
Posts: 10822
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 89
Rate this member

Report this Post08-10-2013 10:06 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
If you are replacing what you think are original parts, the car has been neglected. One can of fuel injector cleaner is not enough to fix the injectors....I am pretty sure they are still fouled up. You can continue using injector cleaner for a while, or take them off the car and get them cleaned.
IP: Logged
Bruce
Member
Posts: 2189
From: Ventura, California, USA
Registered: May 99


Feedback score: (2)
Leave feedback

Rate this member

Report this Post08-10-2013 12:16 PM Click Here to See the Profile for BruceClick Here to Email BruceSend a Private Message to BruceEdit/Delete MessageReply w/QuoteDirect Link to This Post
My 86GT had the same problems yours is experiencing. I replaced the fuel injectors, sensors, etc., etc., and it turned out to be cracked vacuum lines. After having new lines installed, the engine was smooth again.
Hope that helps!
bb
IP: Logged
Damorgan
Member
Posts: 93
From: Lexington, Tennessee. USA
Registered: Aug 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post08-10-2013 12:35 PM Click Here to See the Profile for DamorganClick Here to Email DamorganSend a Private Message to DamorganEdit/Delete MessageReply w/QuoteDirect Link to This Post
My car does the same exact thing except its when I get on it..If I floor it Ill start to sputter real bad and suffer quite a bit of power loss. Im also running very rich and I cant figure out why. I do hear a slight vacuum leak so it may very well be a vacuum problem, but I am replacing my ignition coil and Im getting some plugs with a higher heat range, I think that that would be a good place to look as well
IP: Logged
st88fiero
Member
Posts: 43
From: Long Island, NY
Registered: Jul 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post08-10-2013 06:01 PM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thank you all for ideas. I wish it was a vacuum line, but we have checked them all and do not believe that is it. Although the parts are original, it not necessarily that the car was neglected, it was in storage for quite a long time so all of the rubber, seals, gaskets etc: are in perfect shape so the vacuum lines are also in great shape, in fact that is where we have been applying the intake cleaner solution. If you see this car, you would not believe that it was running bad because it looks almost brand new, and I mean everything top to bottom is in near perfect shape except for being 25 years old. (one of the sun visors looks a little loose and the seat has a little scuff in the leather ;-))

What about a valve the is just not seating properly, or maybe even cracked/broken, could that cause these symptoms?
IP: Logged
st88fiero
Member
Posts: 43
From: Long Island, NY
Registered: Jul 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post08-17-2013 10:13 PM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
***update*** I just wanted to update this post, as of right now the car is all but fixed. What do I have to thank for this...... Seafoam intake manifold cleaner.

After going through just about everything possible that we could have that was making the car run horrible, my mechanic spent a week running this product through the engine. He used two full cans of this product. Both times did the same procedure, let car run and get up to operating temperature unhook vacuum line, open can, insert hose, let entire can of product be drawn into engine, let run for a short period of time, then shut off. Let car sit for hours, even days, Start and run getting up to temperature, then drive it, making sure you drive it aggressively. The car will smoke like a house on fire and anybody within a half a mile will hate you, but it works. It is like crop-dusting, but actually quite fun seeing the look on peoples faces when they think you car is about to explode at a stoplight, or going down the road, it really is quite a scene, but well worth it.

I was to the point that we were considering tearing into the engine to see if there was a bad valve, this was a last ditch attempt and it worked, like a charm. The car has completely transformed, it's actually better them i was hoping for.

I just came back for another "test" run and the car is performing incredible, I'm not sure why most folks trash the 2.8 in these cars, my car is moving along quite well for what it is.

If anbody is looking for a way to really clean out a "gummed" up engine, I would recommendnd this product.

[This message has been edited by st88fiero (edited 08-17-2013).]

IP: Logged
st88fiero
Member
Posts: 43
From: Long Island, NY
Registered: Jul 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-03-2013 10:39 PM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
***Update*** .... after the Seafoam treatment, the car was running much better than originally. After I spent some time and logged a few hundred miles on it, I still felt that the car was not 100%...more like 80% right. It was still running very rich, would have very slight sputter from time to time and just didn't seem what it should be (or at least my memory of the few Fieros i had owned in the past) so back to mechanic it went, he looked over every possible item it could be, then after a week or so he pulled the intake off to get at the injectors, he did every test possible to determine if one was bad but everything was coming back as inconclusive, but he felt that with every thing else being spot on, it had to be one or all the injectors, but there was no way to 100% sure which one.

So i took the risk and said f - it, change them all, lets see what happens.

I am happy to report that at this moment the car is running, dare I say, PERFECT, it is better then I could have ever hoped for ($750 dollars worth, but worth it IMO).

So if anyone else is out there and pulling their hair out with a car that has had some of the same symptoms that I was going through....it may just be the injectors, even if there is no way to determine that they were bad, they were.

Now the car even without the CAT only has a slight oder while running, the idle is completely smooth (when sitting in car you can barely feel it idling), throttle response in instantaneous, will light up the tires with just a simple dump of clutch (instead of the 4k whole shot I was having to do before the change), start-up is as smooth and consistent as new car.

I am just completely blown away how bad a car can run by having a bad set of injectors and how much it can really hamper what I still think is a great little motor in an awesome little car. I'd almost call it a sports car now...Cheers!

[This message has been edited by st88fiero (edited 10-03-2013).]

IP: Logged
mrfiero
Member
Posts: 8988
From: Colorful Colorado
Registered: Mar 99


Feedback score:    (91)
Leave feedback





Total ratings: 149
Rate this member

Report this Post10-04-2013 12:51 PM Click Here to See the Profile for mrfieroClick Here to Email mrfieroSend a Private Message to mrfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm glad you finally figured it out and that your Fiero is now running right.

Now.....it's time for you to learn how to tinker with it yourself! You could have replaced those injectors yourself for around $100 and spent that other $650 elsewhere! [/lecture]

BTW.....I also like the 2.8. It is what it is and when running correctly is a joy to drive. It is not a powerful engine, but it does get the job done. I've owned a few modified Fieros and can say that I actually prefer driving a stock one.

IP: Logged
hdryder
Member
Posts: 674
From: Virginia Beach, VA, USA
Registered: Apr 2011


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-04-2013 01:15 PM Click Here to See the Profile for hdryderClick Here to Email hdryderSend a Private Message to hdryderEdit/Delete MessageReply w/QuoteDirect Link to This Post
Can anyone recommend one of the many fuel injectors, for the 2.8L, that are available on the RockAuto website?

Prices range from $14.96/ea to$118.99/ea.

Thanks for the help.

[This message has been edited by hdryder (edited 10-06-2013).]

IP: Logged
st88fiero
Member
Posts: 43
From: Long Island, NY
Registered: Jul 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-06-2013 09:43 AM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by mrfiero:

I'm glad you finally figured it out and that your Fiero is now running right.

Now.....it's time for you to learn how to tinker with it yourself! You could have replaced those injectors yourself for around $100 and spent that other $650 elsewhere! [/lecture]

BTW.....I also like the 2.8. It is what it is and when running correctly is a joy to drive. It is not a powerful engine, but it does get the job done. I've owned a few modified Fieros and can say that I actually prefer driving a stock one.


Really???....I was pricing out the injectors, those alone, for good one's were between between 250-300 for the set of six, plus gaskets for the intake, so I was assuming that I would be spending at least twice that with labor...the price also included the 100 different diagnostic items my mechanic did to zero in on the injectors.....I wish i could do my own stuff, don't even have the tools to start with so i am saving there right?.....;-)

IP: Logged
st88fiero
Member
Posts: 43
From: Long Island, NY
Registered: Jul 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-06-2013 10:16 AM Click Here to See the Profile for st88fieroSend a Private Message to st88fieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by mrfiero:

BTW.....I also like the 2.8. It is what it is and when running correctly is a joy to drive. It is not a powerful engine, but it does get the job done. I've owned a few modified Fieros and can say that I actually prefer driving a stock one.


I am also glad to see someone agrees with me!....I know this site is big into modifiers, and that is totally cool, I get it....but if you take this car what it is, a sports car, not a muscle or super car, it really has exactly what the engineers intended it to be, a fun little car that is great in the twisty's, enough power to carry you through them without overpowering the corners, and just enough oomph to get you going out of the turns....and it climbs right up to 100+ MPH without even breathing hard....all this and you can still get 20-25 MPG....and it barely has enough power to hurt the components of the car so the power shifts and keeping the car 4-6k rev range while racing it around does not break anything....I just think it's a wonderful machine, just not going to bring out for 1/4 runs....but try to catch me in the turns.....you better be in a Miata!
IP: Logged
PFF
System Bot

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock