voodoogsx
20+ Year Contributor
- 334
- 23
- Jun 2, 2004
-
Sherman Oaks,
California
Let me start with that I had this issue about 2 weeks ago and thought that I had solved it.
The issue:
I was driving home a couple weeks back and was at a stop light. The light changed and I acceled as normal but as I was going I heard what appeared to be a backfire(that was a first). It happened once or twice when I pushed the rpms up to around 4500, so I kept it under that range till I got home. I parked the car and let it ilde, nothing seemed odd. I later went to a friends house and the same thing occured...just once. I figure if it's only like that when I hit high rpms, I can drive it to work no prob, just drive on low rpms. Yeah, slap me a coulpe times for thinking that was a smart move.
Next day I'm heading in and I start going up "the hill", I start noticing the backfiring a bit more and at lower rpms. It starts getting really bad so I pull over and check the idle, seems to be a bit jumpy. I can't make it up the hill, I've lost a lot of power somehow. I'm able turn around and start heading back home, but now It's getting the backfiring more often and rpms are getting jumpy at 1.5-2k while just coasting down the hill. I manage to drive a few blocks more and get off of main streets. At this point the car is sputtering and almost all power is gone, I pull it onto a side street ,coast to a stop and watch the idle, it's hovering over 200rpms sputtering and spiking....wtf?
I get it towed and start working on finding out what the issue is. I first look for any vac leaks, I check all of the lines and don't find any issues. I check all of the piping, everything is secure, no cuts or anything on the connectors. I check all connections on the car, everything appears to be secure. I go to check the codes(I have dsmlink) and see random misfire
I start the car and it starts fine.....after warming up, idle starts going crazy,
I check the spark plugs, they're old so I replace those. I do a bit of reading on here and looks like it's either my coil pack or transistor. I have some cash for just such a time(dsm piggy bank)and buy the coil pack. nothing changes. I call a friend and borrow his transitor, problem seemes to be solved. I buy the power transistor and install it. car runs fine again. I check for any new codes, since I had pulled lot of stuff off, I note one, manifold differential pressure sensor malfunction. I pull the wire, for the mdps and reinsert it, just in case I might have bumped it. I check all other connections, clear the code and start up. everything is great again....I do however notice that there seems to be a subtle but still noticable increase in vibration at idle. I test it for the next couple days and weekend, with longer drives and harder pulls....the car feels great...mostly. The idle still bothers me, but I don't have any error codes and it's within the range that I had logged before.
I check the dtc's once again and note that the mdps error is on again....strange....I might have bumped it when I was putting the strut bar on, I fiddle with it again and clear the code. drive it again, no cels everything is fine.
Flash forward to yesterday. driving home, halfway point, I've been on the road for 20 mins so the car is warmed up. feels fine. Again at a light. I start to accell...and the car stuters, then I coast it to the side of the road. The idle is going crazy, but settles at just above 0.....it doesn't even look like it's getting a reading, just spiking to 100-300 rpm every couple of seconds.....I start smelling something, sort of sulfuric, but not quite sure....I try to see if the car can move, but when I hit the gas it's a slow rev, just doesn't want to go. At this point it's sounding like I've got motorcycle with the way the idle is goin. I've got my computer with me since I logged my drive to work that day...I should have logged it on the way back. Anyway, I look at the dtcs and note Random misfire detected and the MDP error again. I kill the engine and and wait a minute, then start it, it starts but still crazy idle. at least it starts. Another note, is that even with the low rpm, it doesn't die, it just hovers above a complete stall.
I kill the engine again and starting looking under the hood, I check all vac lines, sensors, everything that I can with a mini mag at night with a hot engine. I call a tow service and get the car towed. While waiting, I check the spark plug lines, the transistor and the coilpack, they are all secure and connections are on securly. I bust out the toolbox and make sure that the spark plugs are still in securly, they are. 2 hours later and I'm home. With the car in the driveway and now cool, I start it. Starts up fine, but a few mintues later as it warms up, the rpms start going crazy again....
I guess the first thing is to look at the mdp, but has anyone had this happen when their mdp has gone out, are there other things that I should check? EGR??
I tried to find info on the mdp, but there wasn't much in the way of issues related, just questions on blocking the egr and where the thing is located.
Anyway, things that I've changed so far that have wires connected.
The isc and fiav are less than a year old. I have a bored tb that's been on the car since February. As stated above, I changed out the spark plugs(NGKs got them at rre one day when I was getting other parts and had them gapped), the power transistor and coil packs. DSMlink. New starter.
EGT gauge(I checked that the temp sensor was still secure).
I installed a new stereo in the car about two weeks prior to having the first problem. When I had the rear seat out I fiddled with the fuel pump just to make sure it was secure and that all wires were okay. I didn't unplug anything though. I checked the grounds for the stereo and all were secure to the chasis. The amp that I installed has a fused hotwire directly to the battery. This was the last thing that I had done with the car prior to the issue coming up. I've checked the wiring, made sure that everything was wrapped and nothing exposed. I did this twice.
Any ideas or insight would be appreciated...
The issue:
I was driving home a couple weeks back and was at a stop light. The light changed and I acceled as normal but as I was going I heard what appeared to be a backfire(that was a first). It happened once or twice when I pushed the rpms up to around 4500, so I kept it under that range till I got home. I parked the car and let it ilde, nothing seemed odd. I later went to a friends house and the same thing occured...just once. I figure if it's only like that when I hit high rpms, I can drive it to work no prob, just drive on low rpms. Yeah, slap me a coulpe times for thinking that was a smart move.
Next day I'm heading in and I start going up "the hill", I start noticing the backfiring a bit more and at lower rpms. It starts getting really bad so I pull over and check the idle, seems to be a bit jumpy. I can't make it up the hill, I've lost a lot of power somehow. I'm able turn around and start heading back home, but now It's getting the backfiring more often and rpms are getting jumpy at 1.5-2k while just coasting down the hill. I manage to drive a few blocks more and get off of main streets. At this point the car is sputtering and almost all power is gone, I pull it onto a side street ,coast to a stop and watch the idle, it's hovering over 200rpms sputtering and spiking....wtf?
I get it towed and start working on finding out what the issue is. I first look for any vac leaks, I check all of the lines and don't find any issues. I check all of the piping, everything is secure, no cuts or anything on the connectors. I check all connections on the car, everything appears to be secure. I go to check the codes(I have dsmlink) and see random misfire
I start the car and it starts fine.....after warming up, idle starts going crazy,
I check the spark plugs, they're old so I replace those. I do a bit of reading on here and looks like it's either my coil pack or transistor. I have some cash for just such a time(dsm piggy bank)and buy the coil pack. nothing changes. I call a friend and borrow his transitor, problem seemes to be solved. I buy the power transistor and install it. car runs fine again. I check for any new codes, since I had pulled lot of stuff off, I note one, manifold differential pressure sensor malfunction. I pull the wire, for the mdps and reinsert it, just in case I might have bumped it. I check all other connections, clear the code and start up. everything is great again....I do however notice that there seems to be a subtle but still noticable increase in vibration at idle. I test it for the next couple days and weekend, with longer drives and harder pulls....the car feels great...mostly. The idle still bothers me, but I don't have any error codes and it's within the range that I had logged before.
I check the dtc's once again and note that the mdps error is on again....strange....I might have bumped it when I was putting the strut bar on, I fiddle with it again and clear the code. drive it again, no cels everything is fine.
Flash forward to yesterday. driving home, halfway point, I've been on the road for 20 mins so the car is warmed up. feels fine. Again at a light. I start to accell...and the car stuters, then I coast it to the side of the road. The idle is going crazy, but settles at just above 0.....it doesn't even look like it's getting a reading, just spiking to 100-300 rpm every couple of seconds.....I start smelling something, sort of sulfuric, but not quite sure....I try to see if the car can move, but when I hit the gas it's a slow rev, just doesn't want to go. At this point it's sounding like I've got motorcycle with the way the idle is goin. I've got my computer with me since I logged my drive to work that day...I should have logged it on the way back. Anyway, I look at the dtcs and note Random misfire detected and the MDP error again. I kill the engine and and wait a minute, then start it, it starts but still crazy idle. at least it starts. Another note, is that even with the low rpm, it doesn't die, it just hovers above a complete stall.
I kill the engine again and starting looking under the hood, I check all vac lines, sensors, everything that I can with a mini mag at night with a hot engine. I call a tow service and get the car towed. While waiting, I check the spark plug lines, the transistor and the coilpack, they are all secure and connections are on securly. I bust out the toolbox and make sure that the spark plugs are still in securly, they are. 2 hours later and I'm home. With the car in the driveway and now cool, I start it. Starts up fine, but a few mintues later as it warms up, the rpms start going crazy again....
I guess the first thing is to look at the mdp, but has anyone had this happen when their mdp has gone out, are there other things that I should check? EGR??
I tried to find info on the mdp, but there wasn't much in the way of issues related, just questions on blocking the egr and where the thing is located.
Anyway, things that I've changed so far that have wires connected.
The isc and fiav are less than a year old. I have a bored tb that's been on the car since February. As stated above, I changed out the spark plugs(NGKs got them at rre one day when I was getting other parts and had them gapped), the power transistor and coil packs. DSMlink. New starter.
EGT gauge(I checked that the temp sensor was still secure).
I installed a new stereo in the car about two weeks prior to having the first problem. When I had the rear seat out I fiddled with the fuel pump just to make sure it was secure and that all wires were okay. I didn't unplug anything though. I checked the grounds for the stereo and all were secure to the chasis. The amp that I installed has a fused hotwire directly to the battery. This was the last thing that I had done with the car prior to the issue coming up. I've checked the wiring, made sure that everything was wrapped and nothing exposed. I did this twice.
Any ideas or insight would be appreciated...
(thank goodness for a backup car!)
