O.K., I'll try to make this long story as short as possible(I did say TRY). A few weeks ago I'm driving home from a wedding and I was in second gear and I went to shift into third and lost enough power that I thought I missed and went into fifth, I did'nt, I went back into second and still had no power. Now I tried to wind second out as far as I could, but could'nt get much out of it and when I went to shift into third, she back fired something fierce and all I could smell was gas and exhaust. I pulled over and she shut off. I could not get her to start for a little while but then she started and I drove home in third gear and the rpms would not go over 3000. I found later that the idle air control sensor was very loose and we tightned it and now the car idles fine but still has only half the power. I had the car scanned at a local garage and no hits came up, and about three people told me to check the cat, they said it may be clogged. So, now I've disconnected the cat and it's very loud but still is the same power wise. Two other peaple at the parts store said that the fuel filter can clog and cause a loss of power, so I went and bought a new one but havent tried it yet, my question is... does anybode have any other suggestions on where to look just in case it is'nt the fuel filter? The car idles fine but I can't get it over 3000rpms. Any help would be greatly appreciated! P.S. It's a 87 gt with 75,000 miles and I only got to drive it for about a week after 3 years of restoration. Thanks, Mike.
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11:57 PM
PFF
System Bot
Jun 9th, 2007
topher_time Member
Posts: 3231 From: Bailey's Harbor, for now. Registered: Sep 2005
Have you checked the air filter lately? Maybe the engine is on it's way out- loss of compression or missing cam lobes- my 88GT did a similar thing when the camshaft lost some intake and exhaust lobes.
edit- check your sensors, maybe something's loose
[This message has been edited by topher_time (edited 06-09-2007).]
Cars not revving above 3k for me was 1. blocked cat and 2. fuel filter. The 2nd one would light the SES when I pushed the throttle past about halfway, but never set a code.
RPM problems, other than an internal failure like the cam lobes above, seem to be not enough air in or out, not enough fuel in or out.
Is the engine making any kind of noises while it runs?
Mechanics always say it's a fuel filter... then they replace that, and then charge you to fix the real problem I second a blocked cat or fuel filter. I strongly doubt that an air filter wouldn't clog that suddenly. You can tap gently on the cat and listen for anything rattling around. Sometimes you can hear it when driving. It can also cause your manifolds to get extremely hot.
If it's neither of the above, check compression. No symptoms like smoking or steaming exhaust, "chocolate milk" oil, or oil in the coolant?
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01:01 AM
frankenfiero1 Member
Posts: 441 From: maryville TN USA Registered: Oct 2006
Same thing happened to me back in 1990 when my '88 GT had about 25K miles. I was cruising along and suddenly had no power.....I couldn't get above 20MPH! I limped it to the Pontiac dealership and it was a bad catalytic convertor. Luckily for me it was replaced under warrany (they even replaced the EGR tube!). Try the fuel filter first though....it's like that new girl down the street (cheap and easy) then tackle the cat. What I used to do when a cat would poop out on me was to remove the EGR valve. It was loud as heck and the decklid got very hot, but it relieved enough pressure that the car would drive normally.
You may also check your fuses.......sometimes you'll blow one of the injector fuses, which shuts down half the cylinders (I doubt this is the prob., but it is another cheap & easy fix).
Good luck!
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05:25 AM
project86gt Member
Posts: 39 From: Fort Wayne,Indiana USA Registered: May 2007
If you can get away with it in your area,delete the cat all together(that's what I did)it'll even sound good with a good muffler...You can get the pipe from the fierostore...
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08:03 AM
rager87gt Member
Posts: 176 From: Johnstown PA Registered: Jun 2005
First of all, thanks for all of the input, again, I appreciate it. Now to answer some questions... I completely eliminated the cat by disconecting it from the exhaust and still had no power and it did not make any noise when removed (like anything loose in there). Then, the car sounds great when idleing, it does'nt tick, tap, or anything else. The air filter is brand new and we even tried it after removing the intake tube. Also, the car is not smoking when running. So, hopefully it's nothing internal and I still have not changed the fuel filter yet (too busy) but when I do I'll keep you all posted. Thanks a bunch, Mike.
What I used to do when a cat would poop out on me was to remove the EGR valve. It was loud as heck and the decklid got very hot, but it relieved enough pressure that the car would drive normally.
While this would work, Instead of removing the EGR valve, I recommend removing the O2 sensor. Easier to do, you don't have to worry about a gasket or a broken tube or blocking off the intake side of the tube.
Have you considered replacing your ignition module?
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10:41 AM
Toddster Member
Posts: 20871 From: Roswell, Georgia Registered: May 2001
If the initial problem was your IAC then I would check out the rest of the TBI first. It might not be opening all the way and/or the venturies could be clogged. Before I start replacing parts I'd look at that.
If that is OK, then the next usual suspect in power loss is a vacuum leak or exhaust leak. Assuming you could hear an exhaust leak and haven't I'd check the vacuum lines and hose to make sure they are all OK. Check out the MAP system too (sensor and solinoid) for functionality.
3rd on the to-do list should be the cat and muffler. If the cat goes bad and starts to disintigrate, where do you tink all the crap ends-up? Yep, in the muffler.
4th thing to examine is the vapor canister because you mentioned a gasoline smell. It might be clogged beyond recognition.
NOT muffler or cat if you ran open exhaust and still had problem if no codes,then do simple checks first,,lay 2 used spark plugs with 60 gap on block,grounded,,one from each bank(do not remove plugs) check for hot spark, then turn on key to prime system open valve to make sure there is strong spray,now check all visible connections,use care and pull connectors apart check for corrosion or bad fit clean if necessary check the ground wires eyeball the obvious suspects check to make sure connections are tight,most important ground wire is the one from battery to frame, I once walked 12 miles home because aaa did not show up and it turned out to be the main ground wire it seem tight and i have worked as a mechanic do not over lok the easy stuff do it first let us know stan
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11:21 AM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
Hmm, the Fiero I bought last fall developed a similar problem. I just bought the thing, it was a nice lo mile notchie that was stored for probably 15 years. Figuring the fuel filter, I went to replace it. When I got under there, the filter looked like it had just been replaced, uh oh. Took it off anyway and it was blocked. Checked the fuel tank and found it rusted inside. So in went a new tank (used) and a new fuel pump. All better now. One thing bothers me about your problem is the backfiring and smelling gas. Mine did not backfire at all, just no power. By all means, replace the filter, but if that doesn't fix the problem, start looking at the ignition system, timing, ect.
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07:55 PM
fieroluv Member
Posts: 1951 From: Ft Wayne, IN USA Registered: Jul 2002
Without seeing it, it's very hard to diagnose, however timing chains will always jump when load is relieved; i.e. in between gears. So if the fuel filter doesn't fix the problem the next thing I would check is your cam timing and I know that is not an easy thing to check on these cars.
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08:23 PM
mrfiero Member
Posts: 9008 From: Colorful Colorado Registered: Mar 99
I would go and get a simple fuel pressure gauge and go from there after checking fuel pressure.
Aha! This is a very good suggestion. I had another '88 GT that had a failing fuel pump. I could drive it for a few blocks before it would overheat (the fuel pump) and sputter. Stopping for a few minutes "cured" it and I could drive another few blocks. I did this for about 10 miles!
So, I would check your fuel pressure too......a faulty fuel pump could be to blame as well (I would still check the fuses though....you never know).
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11:55 PM
Jun 11th, 2007
rager87gt Member
Posts: 176 From: Johnstown PA Registered: Jun 2005
Thanks again guys for all the suggestions, I needed some direstions to go in, I will try the fuel filter hopefully tuesday or wednesday. MarkS, I'm pretty sure that the car backfired and smelled due to the loose idle air control sensor, cause before I tightned it, it idled very rough but now it will idle fine. Thanks, Mike.
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12:08 AM
frankenfiero1 Member
Posts: 441 From: maryville TN USA Registered: Oct 2006
Check your injector fuses. They're marked TBI 1 and TBI 2 on the fuse box. One fuse runs each bank of injectors. The fuse that runs the front bank (IIRC) also feeds the EGR solenoid. The solenoid can short out and take out the fuse that runs those injectors. I know of at least one instance where this happened.
------------------ Raydar 88 4.9 Formula IMSA Fasback..........................88 3.4 coupe -soon to be something other than red Read Nealz Nuze!Praise the Lowered!
[This message has been edited by Raydar (edited 06-11-2007).]
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05:55 AM
nu2fiero Member
Posts: 111 From: Walnut Grove MO. USA Registered: May 2006
Had a problem just like that one time and it ended up being a simple PCV valve stuck open causing low vacume to map sensor. But be sure to check the fuel pressure after replacing that fuel filter. Good luck.
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06:46 AM
PFF
System Bot
ltlfrari Member
Posts: 5356 From: Wake Forest,NC,USA Registered: Jan 2002
Since it seemed to happen very suddenly but idles fine I'd got for slipped timing. Either timing chain (unlikely) or distributor failure some where. My old DOHC was like that when I first set it up, idled great but ran like crap, no power. Turns out I had the timing pickup wires the wrong way round and the timing was off just enough. At low rpm it does not matter but as the rpm increase timing becomes more critical and the error was enough to cause all sorts of problems. So I'd check ti timing first. Cheap and easy to do!
Dont trouble shoot just the symptoms. Troubleshoot the situation. You shifted, and noticed the problem immediatly. IT was not a gradual thing. Also, loss of power and backfiring. THis is classic timing chaing jumped a tooth scenario. Get a timing light and check your timing. Whats that gonna cost? Shotgunning parts eg coil, fuel filter, distributor, etc is just ridiculous.
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06:47 PM
frankenfiero1 Member
Posts: 441 From: maryville TN USA Registered: Oct 2006
O.K., tomorrow I'm changing the fuel filter, don't get me wrong, I'm taking all of the good suggestions and marking them down. I'm only changing the filter because I already bought it and I might as well try it. I'll check the fuel pressure, coil, timing chain, and the fuel injector fuses. I'm so hoping that this is not an internal problem cause i'll have to put the car away agian until I can afford a 3800sc swap! (which will be a looong time) Anyway, I'll let everyone know what I find tomorrow. Later, Mike.
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10:56 PM
Jun 12th, 2007
86GT3.4DOHC Member
Posts: 10007 From: Marion Ohio Registered: Apr 2004
I would do the fuel filter, as its standard maintenance and who knows when it was done last, but I wouldnt hold my breath on it fixing it
Next change the coil. Its the most likely, and it fits the symptoms.
Check the fuel pressure, its easy
It wouldnt be running with a blown injector fuse, that would take out a full bank, and while you might be able to keep it flopping over it would run rough as hell.
The cat, well everyone always blames the cat, and I dont even remember the last time that was actualy the problem in one of these threads.
Timing chain is a possibility, but its at the far end of the likely spectrum.
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07:42 AM
rager87gt Member
Posts: 176 From: Johnstown PA Registered: Jun 2005
RAYDAR!!! It was the fuse marked tbi2, We changed the fuel filter and it looked 20 years old but still was free of any obstructions. So we started looking elsewhere and I metioned to my dad that there were the two fuses so he checked them and sure enough, #2 was blown, we replaced it and it runs great now! Thanks so much to everyone for all of the great advice and hopefully I'll never need any of it. Later, Thanks again Mike.
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03:42 PM
86GT3.4DOHC Member
Posts: 10007 From: Marion Ohio Registered: Apr 2004
Wait, you DROVE the car in third gear with 3 cyls dead? I lost an injector fuse once, I couldnt even get it across the gas station parking lot, in fact, I dont think I could even get it started.
Well at any rate, keep in mind the EGR solenoid feeds off of one of those fuses, so if it pops again, try unplugging the solenoid.
And if it does act up again, change the coil, the will often work fine when cold the crap out when hot, only to work fine when they cool. Lol, if I had a nickname on here it would probably be "coils" cause thats what im always reccomending, but Ive been right a lot.
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03:45 PM
PFF
System Bot
mrfiero Member
Posts: 9008 From: Colorful Colorado Registered: Mar 99
Hey Mrfiero and Raydar, don't fight, besides the next thread I read asking for advice on a similar problem, I'm gonna suggest checking the injector fuses and I'll try and get it posted before both of you!!! lol! Later, Mike.
P.S. frankenfiero1, It does idle a hell of a lot better now!
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10:10 PM
Raydar Member
Posts: 41280 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Hunnnh? No fighting to it. It's all good. I've known Mike (mrfiero) for years. I just brain-cramped and missed that he had already posted the same thing that I did. Old age will make ya' do stuff like that.
Check to make sure your getting spark (and a strong spark) to all cylinders. I had a car that was a V6 and was loosing spark to two cylinders. The car would idle fine and you could even sit there out of gear and it would rev up ok to. If you tried to put it in gear and drive it anywhere you wouldnt be able to get it above 20 and it would stumble all the way up there. Lets just say it took me a very long time to figure it out.
Jason
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10:25 PM
Jun 13th, 2007
mrfiero Member
Posts: 9008 From: Colorful Colorado Registered: Mar 99
Hunnnh? No fighting to it. It's all good. I've known Mike (mrfiero) for years. I just brain-cramped and missed that he had already posted the same thing that I did. Old age will make ya' do stuff like that.
Oh it's a fight alright! Bring it on!!
I figured my suggestions got lost in the drivvle I wrote about the cat and fuel pumps......everyone's eyes glazed over before they saw the part about the fuses. Oh well.......poop on you!
[This message has been edited by mrfiero (edited 06-13-2007).]
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04:48 PM
wayman Member
Posts: 191 From: port charlotte,FL. 33980 Registered: Jan 2006