Runs Rough when WARM... Ideas?
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
Runs Rough when WARM... Ideas?
Hi,
I'm looking for some advice on what to try to solve my issue.
I have a 1990, all stock, with ONLY 21,000 miles. Over the last
few months, the car seems to run fun for the first 20min. Then
it starts to run rough...you can feel it most when at idle and in DRIVE,
but you can still tell it is running rough when moving as well.
This weekend, it got to 85 here in Baltimore, and after about 35min,
the car almost just quit while I was going 70mph. I was low on
gas (reserve with only 1 bar on the display), so I was able to
limp it to a gas station. I got gas, the problem was still there. No
power, could barely get it above 25mph. I let it sit for 2-3hrs, it
got me home, but still ran rough. Any ideas on steps to fix this?
Like I said, it is 18yrs old with the original wires/plugs/cap/rotor/etc.
Should I attack there first? What about fuel? New filter? Should
I mess with the idle air bypass stuff?. Being that it is worse when
it heats up, I'm thinking it isn't fuel related.
Any thoughts and ideas would be great. Thanks!
90 White Lightninghttp:
I'm looking for some advice on what to try to solve my issue.
I have a 1990, all stock, with ONLY 21,000 miles. Over the last
few months, the car seems to run fun for the first 20min. Then
it starts to run rough...you can feel it most when at idle and in DRIVE,
but you can still tell it is running rough when moving as well.
This weekend, it got to 85 here in Baltimore, and after about 35min,
the car almost just quit while I was going 70mph. I was low on
gas (reserve with only 1 bar on the display), so I was able to
limp it to a gas station. I got gas, the problem was still there. No
power, could barely get it above 25mph. I let it sit for 2-3hrs, it
got me home, but still ran rough. Any ideas on steps to fix this?
Like I said, it is 18yrs old with the original wires/plugs/cap/rotor/etc.
Should I attack there first? What about fuel? New filter? Should
I mess with the idle air bypass stuff?. Being that it is worse when
it heats up, I'm thinking it isn't fuel related.
Any thoughts and ideas would be great. Thanks!
90 White Lightninghttp:
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
I'm going to have the codes checked this week. Looking over some of these other threads brings other ideas in...Coolant Sensor :>). I'll see what codes pop up. Do I need a scan tool or can I short some pins and count flashes?
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
I just tried shorting out A&B to read the codes...All I got were the
"1" "2" handshaking code...nothing after the "1" "2" code (even after 3 times flashing the "1" "2" code. Should I try to read the codes just after the car is running poorly?...I was assuming it stored them, etc.
"1" "2" handshaking code...nothing after the "1" "2" code (even after 3 times flashing the "1" "2" code. Should I try to read the codes just after the car is running poorly?...I was assuming it stored them, etc.
Safety Car
Joined: Jan 2006
Posts: 3,566
Likes: 4
From: Mt Laurel NJ
St. Jude Donor '06-'07
Welcome to the Forum from another Maryland guy.
First thing that I would do is to change out the fuel filter. Low miles are nice, but it does not mean you don't need to change the filters. And tuning the car up would also be a great idea. Remember, your car is still 18 years old. Have you ever changed to transmission fluid, or the brake fluid? rear differential? You still need to do this stuff.
Let us know it you need any help.
Randy
First thing that I would do is to change out the fuel filter. Low miles are nice, but it does not mean you don't need to change the filters. And tuning the car up would also be a great idea. Remember, your car is still 18 years old. Have you ever changed to transmission fluid, or the brake fluid? rear differential? You still need to do this stuff.
Let us know it you need any help.
Randy
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
Thanks for the note Randy...I'll look into getting the fuel filter changed. I have not done anything to the car....No Tranny fluid, brake, differential, etc....I would have guessed that those would be OK unless they break down over time as well as usage. Frostbite Falls MD....never heard of it...and I'm a born/raised MD guy....sounds cold though :>)..maybe near Frostburg :>)
Burning Brakes
Joined: Aug 2006
Posts: 1,061
Likes: 99
From: Seattle WA
Check your injectors with an ohm meter. Pull each lead off and put an ohm meter across the two terminals on the injector and look for 16 ohms. I suspect you have a few that are going to be more than a few ohms less than 16.
Time kills the type of injectors on your car, not miles. The coils are bathed in gas, and the insulators break down in all the emissions additives in today's gas causing them to short out and not fire correctly.
Time kills the type of injectors on your car, not miles. The coils are bathed in gas, and the insulators break down in all the emissions additives in today's gas causing them to short out and not fire correctly.
Safety Car
Joined: Jan 2006
Posts: 3,566
Likes: 4
From: Mt Laurel NJ
St. Jude Donor '06-'07
Thanks for the note Randy...I'll look into getting the fuel filter changed. I have not done anything to the car....No Tranny fluid, brake, differential, etc....I would have guessed that those would be OK unless they break down over time as well as usage. Frostbite Falls MD....never heard of it...and I'm a born/raised MD guy....sounds cold though :>)..maybe near Frostburg :>)
It's a good idea to change out those fluids every couple of years, cars are made to be driven, and sitting does not always agree with them.
Randy
BTW, if you used Seafoam in the gas, the injectors are now toast, I have first hand experance on that.
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Melting Slicks
Joined: Jan 2001
Posts: 2,940
Likes: 5
From: Chesapeake VA
You say it starts to act up after the first 20 minutes. Can you explain the circumstances of the 20 minutes? Are you starting the car, then driving it for 20 minutes, and then coming to a stop and noticing that the car runs rough? Have you started it and let it run for 20 minutes to note the time, enigine temp, etc, when the car starts to run rough?
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
I essentially have just started it up, start to drive it, and after about 20min you can feel the "roughness", especially at ideal while in "D". This evening, I went ahead and got a new cap/rotor, something I was going to do anyway, and put them on. I took the car out COLD this time, and it is dog...no power...I floor it and at low RPMs it is OK, but it starts to bog down after the first few seconds when floored...RPMs probably never get above 2500...when I let up on the gas, it helps some. When I'm in PARK (ie - not under any load), and give it gas, it seems to run pretty well.....I don't know...I was going to take it to a guy on Wed to have a look....
So...is it true.....If I used Seafoam in the gas tank for 1 tankfull, my injectors are history?
So...is it true.....If I used Seafoam in the gas tank for 1 tankfull, my injectors are history?
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 28
Likes: 0
From: Eldersburg Maryland
Hey...I just ohm'd my injectors...this is what they read....
7.3, 15.5, 16.4, 11.3, 5.1, 2.5, 16.7, and 7.5
I'm guessing that all but about three of them (the 16.4, 16.7, and 15.5) are history???
I'm assuming just go ahead and replace all eight of them, correct?
How hard a job is this?.....It may be more than I want to tackle right now. I may have the mechanic down the street do it.....
7.3, 15.5, 16.4, 11.3, 5.1, 2.5, 16.7, and 7.5
I'm guessing that all but about three of them (the 16.4, 16.7, and 15.5) are history???
I'm assuming just go ahead and replace all eight of them, correct?
How hard a job is this?.....It may be more than I want to tackle right now. I may have the mechanic down the street do it.....
Safety Car
Joined: Jan 2006
Posts: 3,566
Likes: 4
From: Mt Laurel NJ
St. Jude Donor '06-'07
Hey...I just ohm'd my injectors...this is what they read....
7.3, 15.5, 16.4, 11.3, 5.1, 2.5, 16.7, and 7.5
I'm guessing that all but about three of them (the 16.4, 16.7, and 15.5) are history???
I'm assuming just go ahead and replace all eight of them, correct?
How hard a job is this?.....It may be more than I want to tackle right now. I may have the mechanic down the street do it.....
7.3, 15.5, 16.4, 11.3, 5.1, 2.5, 16.7, and 7.5
I'm guessing that all but about three of them (the 16.4, 16.7, and 15.5) are history???
I'm assuming just go ahead and replace all eight of them, correct?
How hard a job is this?.....It may be more than I want to tackle right now. I may have the mechanic down the street do it.....
If you have any other questions, just let us know.
I did it to my car, not that hard. If you send me your email, I'll send the writeup to you.
Randy
Last edited by RandyJ75; Apr 22, 2008 at 03:51 AM.
