BayAreaZT Posted February 20, 2007 Share Posted February 20, 2007 I started having problems with my car recently. I’ve been getting what feel like a fuel cut at full throttle. The car will lose power instantly throwing me forward, then resume driving normal when I back off. Sometimes I get a loud backfire too. Afterwards I get the RPM err displayed. When I reset it by pressing +10, the RPMs read normal. The car runs fine at partial and ¾ throttle under boost but not at full throttle. Any ideas what could be going on? Quote Link to comment Share on other sites More sharing options...
Warren Posted February 20, 2007 Share Posted February 20, 2007 RPM Errors are usually caused by hall sensor vibrations. Check to make sure it's still rigidly mounted and not loose. You should be able to lift the motor by it if it's installed securely enough. It'll cause all kinds of wierd stuff to happen if it's loose or vibrating at all. Hope it helps, Warren Quote Link to comment Share on other sites More sharing options...
240hoke Posted February 20, 2007 Share Posted February 20, 2007 I second that, its likely the cause. Also need to make sure its adjusted so you see all the magnets for as long as possible. Not jsut a flash when you are setting them up, play with it until you can see then for a couple degrees or it can break up at higher rpms. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted February 20, 2007 Author Share Posted February 20, 2007 I'll check it out but this happens at lower RPMs too. If it's vibrating, wouldn't I get an error message other time besides just WOT? Quote Link to comment Share on other sites More sharing options...
240hoke Posted February 20, 2007 Share Posted February 20, 2007 Have you double checked you fuel maps, and acc pump settings? make sure you dont have any skew numbers in your fuel curve, a instant rich setting can make your car behave like that. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted February 20, 2007 Share Posted February 20, 2007 Check your crankshaft pulley bolt.... The dampers are known for coming loose and causing the symptoms you are seeing. Quote Link to comment Share on other sites More sharing options...
Warren Posted February 20, 2007 Share Posted February 20, 2007 There are really too many things it could be, without knowing exactly which SDS system you are running...there are some minor differences between them. Quote Link to comment Share on other sites More sharing options...
vashonz Posted February 20, 2007 Share Posted February 20, 2007 I had a problem where spark would break up ~3500 rpms due to a bad set of sparkplug wires. I replaced them with an oem set (the kind recommended by SDS) and it fixed my problem. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted February 20, 2007 Author Share Posted February 20, 2007 I have the EM3-F. Hopefully I'll have a chance to take a closer look at everything this week. Quote Link to comment Share on other sites More sharing options...
pallnet Posted March 7, 2007 Share Posted March 7, 2007 I had this problem but it came on at 3500 rpms. The mount was the problem and this is why with the help of Warren my problem was solved by remaking the mount. You can buy one from my site if you don't have the means of making your own. After changing my mount to the new one I made, I could sling my motor up so fast and hold the RPMs at any time with no RPM ERR issues. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted March 7, 2007 Author Share Posted March 7, 2007 Thanks for the suggestion. I actually thought about switching to your mount already. I still haven't had the time yet to fully check thing out though. I planning on switching to magnecor wires too. Hopefully I can go through the engine in the next week or two. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted August 15, 2007 Author Share Posted August 15, 2007 Just to follow up on this thread in case anyone needs the info in the future. This is what I have done so far to eliminate this problem. I switched to Magnecor wires from Taylor and went one step colder on the plugs (BPR7ES). Lowered timing 1* from 26* to 25* at boost levels greater than 9psi. These changes seemed to have cleaned up the stumble but I have not taken the car past 5500rpm yet. The problem used to occur anywhere between 3000 and 4500 rpm. I still plan on changing the mount eventually since I still get the RPM err once in a while but it hasn't affected drivability. Quote Link to comment Share on other sites More sharing options...
Warren Posted August 15, 2007 Share Posted August 15, 2007 Makes total sense, and thanks for the update. It IS, however, noted on the SDS site FAQ's http://www.sdsefi.com/tech.html#Technical%20Updates that Taylor wires are known to cause RPM ERR's... 08/13/02 Ignition Wires We have at least 7 reported cases of ECU ignition interference problems from people using Taylor ignition wire sets. Once replaced with a differrent brand, all these problems disappeared. As such, we cannot recommend the use of these wires with our systems. One user also reported severe RPM ERR codes and stumbling upon fitting replacement Bosch 7mm wires. The problems disappeared when the Accel wires were refitted. This info is also in the Troubleshooting section of their Supplemental manual. http://www.sdsefi.com/em4f16.pdf Spark plug wires, and Interference ProblemsAlways use radio suppression type spark plug wires. NEVER use solid core wires. Recommended wires: Magnecor, MSD superconductor, NGK, OEM or factory carbon string, Accel 8.8 yellow. Important! Wires which have caused interference problems in the past are Nology, Mallory and Taylor, so we do not recommend these. If you have these wires and are having problems try a different brand of wires. Ignition interference problems usually show up as strange characters in the programmer screen, rough running, misfiring or an RPM ERR code in gauge1 mode. Not trying to be a smartass or anything, just putting the reference materials in the thread for future "searchers". Glad you're seeing a difference since you got rid of the Taylors...those, were probably 95% of the issue you're dealing with. Again, thanks for the followup. Warren Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted August 15, 2007 Author Share Posted August 15, 2007 Warren I did read that on the SDS website months before my problem popped up and I planned on changing to Magnecor eventually. I put it off because I had no problems with the Taylors at 8psi when I was tunning. At 10 psi I started having problems however, the problem did not go away by just changing to Magnecor wires. I agree the wires were probably a big part of the problem but the plugs and timing made a difference too. Quote Link to comment Share on other sites More sharing options...
Warren Posted August 15, 2007 Share Posted August 15, 2007 Like I said Dale, I was only putting the reference materials into the post for future searchers... I'm sure the plugs and timing change made a difference as well. Warren Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted August 15, 2007 Author Share Posted August 15, 2007 Thanks for putting it in there. Definitely valuable info. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.