I just recently acquired an 1988 GT 5speed with 38,000 miles.
As far as I can tell the car is mostly stock with the exception of K+N air filter and the cat had been eliminated. The car, according to the last owner had only been driven 2000 miles in the past 10 years, and it mostly sat in storage over the past 3-4 years with the exception of a few short trips. 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.
I am trying to see what other issues can be causing the running rich, slight hesitation issue. It's as if the car, at lower RPMs just runs a little rough and is not exhibiting full power unless I am really on it, (It will lay wheels if I launch it) but it's just not "happy" otherwise.
Also i have the dreaded pegging tempeture gauge issue. I have changed the thermostat and the temp. sending unit, and have confirmed the car is in fact running at proper temp., but when the car starts, and the gauge does the sweep, it just locks at the top and I have to bang on the top of cluster to get it to go back down. Does any body know for sure the fix for this? I have read multiple fixes from changing the wiring or swapping out the gauges, but I'm not sure which way to go and don't want to waste $160 on parts from the Fireo Store if fixing the gauge is not going to correct the problem, anyone else suffer from this issue?
And on last item (for now!), has anyone used West Coast Fiero front license plate mount?
I live in NY so i will have to put plate on front and do not want to damage the nose, this car is almost show quality and do not want to harm it.
Also i have the dreaded pegging tempeture gauge issue. I have changed the thermostat and the temp. sending unit, and have confirmed the car is in fact running at proper temp., but when the car starts, and the gauge does the sweep, it just locks at the top and I have to bang on the top of cluster to get it to go back down. Does any body know for sure the fix for this? I have read multiple fixes from changing the wiring or swapping out the gauges, but I'm not sure which way to go and don't want to waste $160 on parts from the Fireo Store if fixing the gauge is not going to correct the problem, anyone else suffer from this issue?
Save your money. The pegging temperature gauge problem is a GM wiring design error, and fixing the wiring will cure it ... guaranteed. There are at least two different ways to perform the fix, and there are numerous threads in the PFF archives that describe how to do it. Sorry, I don't have time to find them for you right now. You can use the PFF search (or Google) to search on "pegging temperature gauge."
Actual rich running could be 02 sensor. Cold start injector not stopping?
Make sure no one put in some sort of performance computer chip thingamabob when they did the cold air intake.
Sorry I dont have alot fo how to fix ideas, just starting ideas
I think the timing is ok and the is no check engine lights, it just is loading up at bit and running very rich. I am trying to avoid just throwing parts at it.
I think the chip is located in the console, correct? I can check to see if so, but I'm thinking no. The only mods are K/N air filter and no CAT.
My temp gauge is in celcius, so I got a Fahrenheit one. I took apart the dash and replaced the gauge but it would peg (unlike the other one) and it would remain at the same temp throughout a few drives. So I took it out and compared it with the celcius gauge. Turns out that the new gauge would move around violently when I touched it or gave it power. The old gauge would smoothly return to the off position. And yes, my father and I did change the wires. Sometimes, the gauge may be bad.
Might want to check for vacuum leaks. With car sitting that long original lines may need replacing. Leaks may be causing some of the problems you describe.
For the "running rich", it would be a good idea to find someone with an old scan tool (or WinALDL on a laptop) and look to see what the coolant and intake air temp sensors are seeing. (This is not to be confused with the gauge, which uses a different sender.) If either of those sensors is reading colder than actual, it can cause the engine to run rich. The O2 sensor can do the same thing, but it's less obvious when you scan it.
I'm guessing you have a stuck or leaking injector. It's a common problem for injectors that have "sat" for a while. If you have a fuel pressure gauge, connect it to the shrader valve fitting on the fuel rail where the fuel lines connect. (It'll be under a metal cap.) When you turn on the key, the system should pressurize to about 40 lbs. If you then turn off the key, it should hold pressure pretty steadily. If it bleeds off right away, there is a problem. The quick and dirty way to check this is to turn on the key to pressurize the system. Don't start the engine. Then turn the key off. Wait a minute or two, then depress the shrader valve with a small screwdriver or key. Gas should squirt up several feet. (Obviously, you don't want to do this with a hot engine or around any sparks or flame. Don't get your face in the way of the "squirt".) If it just dribbles out, there is a problem.
Always check the vacuum lines first in the case you describe. You'll save a lot of money on sensors, etc., since the vacuum system runs right next to the highest heat components in the engine. bb
I'm guessing you have a stuck or leaking injector.
This the next idea I was thinking about to, it seems to makes sense. I do not have the tools, so it going to mechanic on Tuesday.
Can a bad injector make the car have a bit of "roughness" to it, as stated in post, in the low RPM range (idle), when you just start to step on gas the car just sounds a little rough (almost like a miss) but it not missing, just sounds like it choaking, only for a second, then as soon as the RPM hit 3,000 or so, it off as smooth as could be. If i drive the car around at Wide Open Throttle all the time it great!....just have cops behind me.
I will keep you posted. I so want this car to run right!
I'm guessing you have a stuck or leaking injector. It's a common problem for injectors that have "sat" for a while.
I concur.
quote
Originally posted by st88fiero:
Can a bad injector make the car have a bit of "roughness" to it, as stated in post, in the low RPM range (idle), when you just start to step on gas the car just sounds a little rough (almost like a miss) but it not missing, just sounds like it choaking, only for a second, then as soon as the RPM hit 3,000 or so, it off as smooth as could be.
Those are exactly the symptoms you would expect from one or more injectors that are leaking or stuck partially open. Running a tank of fresh gasoline with a fuel system cleaner like Techron (recommended) through the engine might be enough to fix the problem, and it's not likely to hurt anything. I'd certainly try that before tearing into the engine.
In the V6 in your '88 GT there are a total of seven fuel injectors, one per cylinder plus the cold-start injector. You noted that your mechanic found two spark plugs wet with gasoline. If only those two plugs were wet, that tends to confirm the leaking-injector hypothesis, likely just the injectors for those two cylinders.
[This message has been edited by Marvin McInnis (edited 07-27-2013).]
[/quote]Those are exactly the symptoms you would expect from one or more injectors that are leaking or stuck partially open. Running a tank of fresh gasoline with a fuel system cleaner like Techron (recommended) through the engine might be enough to fix the problem, and it's not likely to hurt anything. I'd certainly try that before tearing into the engine.
Thank you for confirmation, and that is exactly what I have done, I have run techron first, and with last gas fill up I ran an octane boost...it has gotten slightly better but still stinks and have that little roughness to it. Going to have to have the shop look over the injectors.
Did the PO install the air temp sensor? It would have been in the side of the air filter canister, but since you don't have that anymore it should probably be in the snorkel near the filter end.
Did the PO install the air temp sensor? It would have been in the side of the air filter canister, but since you don't have that anymore it should probably be in the snorkel near the filter end.
I do have the air filter canister installed, the only thing missing on my car is the CAT. All else is stock except for K+N air filter
Yes i did install new temp sensor when the gauge first pinned, it did nothing to fix the problem.
[/QUOTE] Save your money. The pegging temperature gauge problem is a GM wiring design error, and fixing the wiring will cure it ... guaranteed. There are at least two different ways to perform the fix, and there are numerous threads in the PFF archives that describe how to do it. Sorry, I don't have time to find them for you right now. You can use the PFF search (or Google) to search on "pegging temperature gauge."I have now driven the car 7 times and it seems that the gauge is not doing it every time now. It is as if the needle gets stuck, and when i hit the console it drops back down. if that is the case, should be changing the gauge or is it still considered a wiring problem?[/QUOTE]
I have now driven the car 10 times and it seems the problem is intermittent, it had occurred 6 out of ten times, and if i just tap on the console it drops back down. Is it possible it is not the wiring and maybe changing the gauge will fix this?
I have now driven the car 10 times and it seems the problem is intermittent, it had occurred 6 out of ten times, and if i just tap on the console it drops back down. Is it possible it is not the wiring and maybe changing the gauge will fix this?
The wiring defect is what causes the gauge to peg during the bulb-test cycle when you start the car. What causes the pointer to stick there is that it sometimes hangs up on the edge of the foam gasket that surrounds the gauge itself, and whacking the aux gauge housing is usually enough to shake the pointer loose. Fix the wiring problem; that will stop the gauge from pegging, which will stop the pointer from getting stuck.
[This message has been edited by Marvin McInnis (edited 07-28-2013).]
I just recently acquired an 1988 GT 5speed with 38,000 miles.
As far as I can tell the car is mostly stock with the exception of K+N air filter and the cat had been eliminated. The car, according to the last owner had only been driven 2000 miles in the past 10 years, and it mostly sat in storage over the past 3-4 years with the exception of a few short trips. 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.
I am trying to see what other issues can be causing the running rich, slight hesitation issue. It's as if the car, at lower RPMs just runs a little rough and is not exhibiting full power unless I am really on it, (It will lay wheels if I launch it) but it's just not "happy" otherwise.
Also i have the dreaded pegging tempeture gauge issue. I have changed the thermostat and the temp. sending unit, and have confirmed the car is in fact running at proper temp., but when the car starts, and the gauge does the sweep, it just locks at the top and I have to bang on the top of cluster to get it to go back down. Does any body know for sure the fix for this? I have read multiple fixes from changing the wiring or swapping out the gauges, but I'm not sure which way to go and don't want to waste $160 on parts from the Fireo Store if fixing the gauge is not going to correct the problem, anyone else suffer from this issue?
And on last item (for now!), has anyone used West Coast Fiero front license plate mount?
I live in NY so i will have to put plate on front and do not want to damage the nose, this car is almost show quality and do not want to harm it.
Thank you for all replies.
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!
