Been having an issue with an intermittent studder. Good response to acceleration in 1st, 3rd and UP. 2nd however is where I occasionally get a studder. It's not everytime, seems only to happen during warm up, and only when I'm in low speed environment (neighborhood or parking lots) and only between 2 and 3k rpm.
Plugs and Wires are new
Crank Pulley is tight - I've reached down there and cannot feel any give at all - no identifiable wobble or shimmy through full range of throttle - It's a '90 with SNC and I've run the list of symptoms but the studder seems to be the only one that I can find associated with the problem.
Installed CAI with open cone filter -Wanted to do it anyway and figured it might help. Definitely sounds better, but it's had no effect +/- on the studder issue. Had chance to check AFM and it's nice and clean.
New PCV valve - figured while I was in there + it's a cheap fix
New O2 sensor - Bosch universal crimped in a vise and soldered
Flushed Radiator, Replaced Thermostat
I've run a couple bottles of gas treatment to clean injectors
I didn't notice the issue until after car had been to body shop for 3 weeks
(Old lady in a Deville couldn't see my red sports car sitting by itself in the middle of an empty parking lot) All she did was wipe out the front fender so I don't think she did anything to cause the studder
Clutch is less than a year old, and tight
I want to address it, hate the idea that something isn't right, I'm just getting tired of replacing parts that don't need replacing yet trying to find it, and I'm not sure what to look at next.
As a follow up, I've spent a lot of time looking at the SNC issue posts. Is the issue something that's inevitable with all '90's or just one that '90's are susceptible to? It's hard to tell by the posts.
Originally Posted by bluerdg
Been having an issue with an intermittent studder. Good response to acceleration in 1st, 3rd and UP. 2nd however is where I occasionally get a studder. It's not everytime, seems only to happen during warm up, and only when I'm in low speed environment (neighborhood or parking lots) and only between 2 and 3k rpm.
Plugs and Wires are new
Crank Pulley is tight - I've reached down there and cannot feel any give at all - no identifiable wobble or shimmy through full range of throttle - It's a '90 with SNC and I've run the list of symptoms but the studder seems to be the only one that I can find associated with the problem.
Installed CAI with open cone filter -Wanted to do it anyway and figured it might help. Definitely sounds better, but it's had no effect +/- on the studder issue. Had chance to check AFM and it's nice and clean.
New PCV valve - figured while I was in there + it's a cheap fix
New O2 sensor - Bosch universal crimped in a vise and soldered
Flushed Radiator, Replaced Thermostat
I've run a couple bottles of gas treatment to clean injectors
I didn't notice the issue until after car had been to body shop for 3 weeks
(Old lady in a Deville couldn't see my red sports car sitting by itself in the middle of an empty parking lot) All she did was wipe out the front fender so I don't think she did anything to cause the studder
Clutch is less than a year old, and tight
I want to address it, hate the idea that something isn't right, I'm just getting tired of replacing parts that don't need replacing yet trying to find it, and I'm not sure what to look at next.
As a follow up, I've spent a lot of time looking at the SNC issue posts. Is the issue something that's inevitable with all '90's or just one that '90's are susceptible to? It's hard to tell by the posts.
Plugs and wires quot;newquot; as in....I've cleaned the engine bay with water AFTER the plug/wire install new? Just asking because, I've had a similar studder on what I would consider new plugs and wires, but we had cleaned the engine bay and got a tiny bit of water down a cylinder and had a plug wire arcing.
The motor has no idea which gear the transmission is in. So if there is actually a difference in 2nd, it would have to be from something really off the wall, like a different resonant vibration only happing in 2nd. Or a wire the shifter is hitting in 2nd, which I've never seen one anywhere close to the shifter.
Sorry I can't be of much help. If the problem just started, maybe it just hasn't reared it's ugly head yet in the other gears.
Originally Posted by Gr8Wite
Plugs and wires quot;newquot; as in....I've cleaned the engine bay with water AFTER the plug/wire install new? Just asking because, I've had a similar studder on what I would consider new plugs and wires, but we had cleaned the engine bay and got a tiny bit of water down a cylinder and had a plug wire arcing.
New as in I picked up a set of each on the way home the first time I noticed it. been there before.
Originally Posted by bluerdg
New as in I picked up a set of each on the way home the first time I noticed it. been there before.
Good luck buddy. Hope you get it figured out
Originally Posted by RADOne
The motor has no idea which gear the transmission is in. So if there is actually a difference in 2nd, it would have to be from something really off the wall, like a different resonant vibration only happing in 2nd. Or a wire the shifter is hitting in 2nd, which I've never seen one anywhere close to the shifter.
Sorry I can't be of much help. If the problem just started, maybe it just hasn't reared it's ugly head yet in the other gears.
I've been dealing with it since late May, what's wierd is I can pull off from a dead stop in 2nd and I don't get it, I've tried to find it in the other gears and the only time it happens is low RPM accelerating out of the shift to 2nd. I'm about ready to swap out the fuel filter. Tach seems to hang tight through the studder which is leading me the think it's a fuel issue. It's not getting any worse (frequency or duration) which makes me think it's not a SNC issue, I'd think that would have gotten worse over time.
Any oil down in the plug wells?
(FYI, it's quot;stutter,quot; not quot;studder,quot; which sounds like a bull teat.)
Your post #1, Seems only to happens during warm-up (your words) . bluerdg , you do not have an issue . It is just an old car warming up . Wait untill it is warmed up before you expect it to run as it should.......
bluerdg: the only thing you have not replaced is the coil pack? have you tried to duplicate same rpm range shift to 3rd or 4th. very wierd issue. a trick i like to use to check coil output is to use a ST-125 spark tester in series with the plug wire at the coil tower, check at each plug wire, start and watch the spark. if the spark stutter/studder or just plain misses you might have a bad coil unless you can duplicate it with regularity it may be difficult to find
I have the same problem. Nobody can pin point it. I might just have to start changing things hoping I find it in the first few tries. I've done a complete tune up and filter changes and nothing. I'm changing the MAS, CAS, and coil pack over the next few months and hopefully one of those is it. Aside from that I'm clueless.
i would suspect the coil-pack. sounds like its starting to go. might have gotten cracked when the car got hit. check for arcing when its dark.
Originally Posted by Bill Strohm
Any oil down in the plug wells?
(FYI, it's quot;stutter,quot; not quot;studder,quot; which sounds like a bull teat.)
I did notice just a bit in well #1 when I pulled the plugs. Maybe it's time to grab a gasket set and pull the valve cover, probably can't hurt. I found some stuff last night searching around about the water temp sensor on the back of the block under the coil pack(green cap) and it sending bad signals to the ECU, causing the car to run rich (my STUTTER is almost like a choking out), might explain the warm up issue. Another issue I had when I got her back from the shop was a coolant smell. I noticed a rusty colored stain developing at the firewall around the heater hoses but never could find a leak until one evening I shined a light back there. I had a pin hole in a hose that was spraying a fine vapor over the area. I pulled the coil pack and cleaned it thoroughly, wiped down all the connections I found but I don't recall seeing a green connector. If it's where I think it is, it would have been in the direct path of the vapor spray, Maybe I'll get lucky and find a dirty connector. |
Post at 2-7 06:13 AM
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