psv Posted January 7, 2021 Share Posted January 7, 2021 Hey, i recently picked up my first Subaru, its a Subaru Impreza WRX STI V-Limited 555 1997. When I picked it up, it had been sitting for almost 2 years. When running, I hear a misfire and it smells of gas. When the engine is running, I can pull the back two coil wires from the coilpack and it has no effect on the engine. When I pull either front ones, the car eventually dies. Is this a common problem? Car has only done 50000km (Japan import). I've changed the coilpack, but the problem is still the same. I also have a code for TPS and O2 sensor if thats relevant. Quote Link to comment Share on other sites More sharing options...
Rampage Posted January 8, 2021 Share Posted January 8, 2021 (edited) Sorry, wrong engine. Edited January 8, 2021 by Rampage wrong engine 1 Quote Link to comment Share on other sites More sharing options...
el_freddo Posted January 8, 2021 Share Posted January 8, 2021 No ignitor on the DOHC turbos @Rampage - they’re coil on plug. Ensure you have the coils plugged in/placed correctly. Cheers Bennie 1 1 Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 8, 2021 Share Posted January 8, 2021 ??? if this engine has a coil and PLUG wires, could easily be a bad coil-pack. Due to waste spark ignition design, a bad coil will kill 2 cylinders. 1&2 OR 3&4 . 1 Quote Link to comment Share on other sites More sharing options...
psv Posted January 8, 2021 Author Share Posted January 8, 2021 12 hours ago, el_freddo said: No ignitor on the DOHC turbos @Rampage - they’re coil on plug. Ensure you have the coils plugged in/placed correctly. Cheers Bennie 1 hour ago, 1 Lucky Texan said: ??? if this engine has a coil and PLUG wires, could easily be a bad coil-pack. Due to waste spark ignition design, a bad coil will kill 2 cylinders. 1&2 OR 3&4 . Thanks for the suggestions guys, going to check the plug wires and spark plugs this weekend. Will update the thread when I've checked them. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 8, 2021 Share Posted January 8, 2021 do you have misfire codes? If you have 2 that are bank specific (P0301 and P0303 for example) you may have a cam sprocket that has slipped it's timing. Quote Link to comment Share on other sites More sharing options...
psv Posted January 8, 2021 Author Share Posted January 8, 2021 30 minutes ago, 1 Lucky Texan said: do you have misfire codes? If you have 2 that are bank specific (P0301 and P0303 for example) you may have a cam sprocket that has slipped it's timing. I only have the O2 sensor code and the TPS. Quote Link to comment Share on other sites More sharing options...
Rampage Posted January 9, 2021 Share Posted January 9, 2021 You said you replaced the coil pack. Is it mounted on top of the intake? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 9, 2021 Share Posted January 9, 2021 Could be a bad external ignitor. The 97 and 98 turbo engines were wasted spark - they typically have an external ignitor mounted on the firewall. GD 1 2 Quote Link to comment Share on other sites More sharing options...
el_freddo Posted January 9, 2021 Share Posted January 9, 2021 Scratch what I said then - only applicable for the early stuff in the RS turbo and early WRX (V1/2). Must be V3/4 onwards that are wasted spark. Cheers Bennie Quote Link to comment Share on other sites More sharing options...
psv Posted January 9, 2021 Author Share Posted January 9, 2021 14 hours ago, Rampage said: You said you replaced the coil pack. Is it mounted on top of the intake? Yes. 9 hours ago, GeneralDisorder said: Could be a bad external ignitor. The 97 and 98 turbo engines were wasted spark - they typically have an external ignitor mounted on the firewall. GD Could the piece saying Diamond on it be the ignitor? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 9, 2021 Share Posted January 9, 2021 Yes that is the igniter. GD 1 Quote Link to comment Share on other sites More sharing options...
Rampage Posted January 9, 2021 Share Posted January 9, 2021 That is it. Upper left corner in photo. The ECU sends signals to it and it controls the coil. There are two power transistors inside of it that act like high speed switches. One transistor controls the front coil in the coil pack (cyl 1 and 2) and the other one controls the rear coil (cyl 3 and 4). They seldom go bad, but 95% chance it is your problem. 1 Quote Link to comment Share on other sites More sharing options...
Rampage Posted January 10, 2021 Share Posted January 10, 2021 Check out this VIDEO from scannerdanner.com on how to check the coil and Igniter with a test light and volt meter and a scope for input and output pluses. Scroll down the page and look at the drawing of how it is wired. If there are no pulses into the Igniter on one of the wires, you will have to trace it back to the ECU. 1 1 Quote Link to comment Share on other sites More sharing options...
psv Posted January 19, 2021 Author Share Posted January 19, 2021 Update: I bought the igniter and the TPS, i got them both in the mail today and tried changing the igniter, still no difference. Any thoughts? Havent changed the TPS yet, but that couldnt be the reason for the misfire, right? Could both the coilpacks I've tried be bad? Quote Link to comment Share on other sites More sharing options...
Rampage Posted January 20, 2021 Share Posted January 20, 2021 Pull the fuel pump fuse so the engine will not run. Start the engine and run it until it dies. Crank it and check for spark out of the coil front and rear. If there is no spark on the rear coil, then follow the video I posted and use a test light to check for pulses into the coil pack and input and output at the igniter. Some of the checks require that the test light clip lead be hooked to battery positive and others connected to the negative. Example: 12 volts is fed into both of the coils in the coil pack on one wire and the igniter will switch a ground to the other end of each coil. Testing those wires plugged into the coil with a test light connected to ground the light will be bright and flicker a little dimmer. If the connector is disconnected from the coil then you move the test light lead to battery positive and then the light will be off and flicker on when there is a pulse. Quote Link to comment Share on other sites More sharing options...
psv Posted January 21, 2021 Author Share Posted January 21, 2021 On 1/20/2021 at 3:11 AM, Rampage said: Pull the fuel pump fuse so the engine will not run. Start the engine and run it until it dies. Crank it and check for spark out of the coil front and rear. If there is no spark on the rear coil, then follow the video I posted and use a test light to check for pulses into the coil pack and input and output at the igniter. Some of the checks require that the test light clip lead be hooked to battery positive and others connected to the negative. Example: 12 volts is fed into both of the coils in the coil pack on one wire and the igniter will switch a ground to the other end of each coil. Testing those wires plugged into the coil with a test light connected to ground the light will be bright and flicker a little dimmer. If the connector is disconnected from the coil then you move the test light lead to battery positive and then the light will be off and flicker on when there is a pulse. Doing this on monday when I get my multimeter in the mail, thanks! Quote Link to comment Share on other sites More sharing options...
psv Posted January 21, 2021 Author Share Posted January 21, 2021 Okay, so I checked the timing today and it looks like its skipped a tooth, but only on one side. See picture below. Could this cause the no spark on two cylinders? And can anyone confirm that it is out of timing? Quote Link to comment Share on other sites More sharing options...
nvu Posted January 21, 2021 Share Posted January 21, 2021 Could be normal with a loose belt or tensioner. Either way, if it's off by one tooth won't cause misfires you're seeing. Get a marker and count the teeth, if it all matches the belt is set correctly. 2 1 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 22, 2021 Share Posted January 22, 2021 No that is no the cause of your problem. GD 1 Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 23, 2021 Share Posted January 23, 2021 does this car have a MAF ? how does it run with the MAF unplugged? 1 Quote Link to comment Share on other sites More sharing options...
psv Posted January 24, 2021 Author Share Posted January 24, 2021 On 1/23/2021 at 8:44 AM, 1 Lucky Texan said: does this car have a MAF ? how does it run with the MAF unplugged? Car came with a brand new MAF which I tried and made no difference from the one that was already on it. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 24, 2021 Share Posted January 24, 2021 (edited) I asked because some cars will revert to 'base' parameters stored in the ECU's memeory if the MAF is unplugged. The idea was this, if the car runs better on the base map, it kinda points to a sensor or sensor wiring/grounding type of problem. if not, then it could be something more 'physical' like a burned valve or .....? GD could explain better. Edited January 24, 2021 by 1 Lucky Texan 1 Quote Link to comment Share on other sites More sharing options...
psv Posted January 24, 2021 Author Share Posted January 24, 2021 2 hours ago, 1 Lucky Texan said: I asked because some cars will revert to 'base' parameters stored in the ECU's memeory if the MAF is unplugged. The idea was this, if the car runs better on the base map, it kinda points to a sensor or sensor wiring/grounding type of problem. if not, then it could be something more 'physical' like a burned valve or .....? GD could explain better. Okay, I dont think I tried running it without the MAF. I don't think it could be a physical fault, because it does not have any spark on two of the cylinders. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 25, 2021 Share Posted January 25, 2021 17 hours ago, psv said: Okay, I dont think I tried running it without the MAF. I don't think it could be a physical fault, because it does not have any spark on two of the cylinders. oh, yeah. Well, if it works like I think, it's easy to try. But, everything now is pointing more to a bad ECU or maybe some odd issue with cam/crank sensor....say, any idea if the engine has had cam or crank sprockets changed? Differences in those from year-to-year can cause problems because the ECU is expecting certain signal 'trains' from cam and crank sprockets. That is, ECU and cam/crank signals must match. Quote Link to comment Share on other sites More sharing options...
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