Guest Anonymous Posted December 20, 2002 Share Posted December 20, 2002 Oddly enough, it wasn't the connectors. I cleaned them off as well as the prongs on the sensors, connected them, and nothing. I experimented with taking the plugs off all together.. the larger center one would make my car run like **** when it was disconnected while the smaller one to the left (more towards the drivers side, right next to it) had no affect when I disconnected it. I'm thinking it could be the temp sensor in the AFM (?) as my car runs perfect when it's immediately cold. As I said, I'm really getting frustrated because something has come up and it's about time for me to start daily driving this car. Any more thoughts? Your guess is as good as mine. Could those sensors just be bad all together? At this point it almost seems like something eletrical is borked, I couldn't find any vacuum leaks. EGR maybe? Chris Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted December 21, 2002 Share Posted December 21, 2002 Its why I go with a standalone... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 22, 2002 Share Posted December 22, 2002 Today I was outside further messing around, looking for vacuum leaks and checking connections. I took out the spark plugs, and guess what, they were black (not oily though). Could this be causing the backfiring through the intake? They certainly didn't look normal. I have a feeling that maybe I could have fouled them when I had the AFM adjusted to way rich during those few days. Could I be getting a weak spark? Perhaps I have fixed the problem but the spark plugs are holding me back now. I will go get a new set tommorow morning and put them in. Edit: I found a chart on the net, they look like this: http://www.verrill.com/moto/sellingguide/sparkplugs/plug_carbon.jpg that chart seems to indicate carbon build up. Chris Quote Link to comment Share on other sites More sharing options...
JKDGabe Posted December 22, 2002 Share Posted December 22, 2002 If you've replaced them recently you shouldn't need to buy new ones, just clean them and see how that does. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 22, 2002 Share Posted December 22, 2002 I went out and bought new spark plugs, just to be safe. Stuck them in, still have the problem. I am confident that I can say the following about how the car runs: 1. Runs awesome when it's cold. 2. After warm up, the car seems to go lean, I get the hesitation, sputtering, and backfiring through the intake. 3. That hesitation seems to occur between 1500-3500 rpms, before or after that range it revs fine. 4. If you try and take it for a drive when it's warm, it bucks, kicks, hesitates, and backfires through the intake between that rpm range, after that it pulls fine. But when it's cold, like I said, it drives like a new car. 5. The fuel pressure and fuel flow are perfect. That's about all I can gather, the problem seems electrical, I just don't know where else to look. I did notice that after I scraped the corrosion off of the two temp sensors on the thermostat it takes a longer time to start, I am not sure if any of those sensors could cause this type of a problem though. Too bad I am sick as a dog, I could have tested another AFM on it last night, although the AFM seems to be doing its job as when you richen it up, the car runs great.. that causes me to fail emissions though. I'm about ready give up. Chris Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted December 23, 2002 Share Posted December 23, 2002 FWIW: Dont give up-The problem is right in front of you, it is just a matter of going thru the process. 1) have you checked your new plugs yet, are they black also?) 2) your engine runs great when it is cold: does it run great when cold through the entire rpm band and under a load? 3) how do you know your engine is going lean? Dont forget the backfiring, spitting, sputtering can also be caused by an excessive rich condition (black spark plugs?). Do you have a spark plug tester? You can check the color of your spark w/a spark plug tester; you may be getting spark but may not be getting enough spark at the correct time hence the black spark plugs. Do you have a factory service manual; it will walk you thru the tesing procedure...step by step. Dont forget to ensure your air filter is clean and your fuel filters (filters as in plural-front fuel filter & rear fuel filter) are clean/new. Unfortunately, not much can be done over the net; you will have to diagnose it according to the factory service manual. Dont give up & keep at it; then once you figure it out you can tell us what your problem was. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 23, 2002 Share Posted December 23, 2002 While I haven't checked the new plugs, I can say that the rest of the engine had a major tune up. Cap, wires, plugs, the fuel system almost totally redone, valve adjustment, and more. The reason I believe it's lean is because when I adjusted the AFM by 16 notches on the loose side (counter clock wise, richer) it ran like a charm, I took it in for emissions and I failed the idle test but passed the revving test. Someone I talk to thinks it could be the temp sensor, I will replace this tommorow as it's only 15 bucks at my local shop here, I'll get a new connctor for it too. I'll keep you informed. Chris Quote Link to comment Share on other sites More sharing options...
Mudge Posted December 23, 2002 Share Posted December 23, 2002 What does the temp look like with your gauges? Could also be an O2 sensor (or multiple), anything that could affect closed loop operation can be suspect. Its almost always cheaper to get a scan tool rented or even bought, unless you really know what your doing, or are lucky. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 23, 2002 Share Posted December 23, 2002 Well, chances are I will be able to test a AFM in good shape on my car tommorow. My buddy that grew up on the L-Jet FI system is 90% sure it's the AFM. Some people grew up with carbs and some L-Jet, he grew up on L-Jet. Will keep you posted. Chris Quote Link to comment Share on other sites More sharing options...
GAZRNR Posted December 23, 2002 Share Posted December 23, 2002 Chr{i}s I chased an AFM problem for a long time too. I could get the car to idle terrible but pull hard or idle good and run like a lame dog. I later found that the vacume hoses going to canister were reversed. Fixed that and got idle & drive ability back. If you have already gone through the process of checking hoses/connections/sensors then it's time for a trip to the Pull-A-Part yard for an AFM. One more thing to check is the cold start sensor on the intake - the shutoff may be bad allowing fuel to drip into the intake causing your low speed rich condition when the engine is warmed up. The pull a part yards are cheap and an afm out of a donor car should be close to where it will run in your car - just pull the cover to verify everything is as it should be under there. Good luck! Quote Link to comment Share on other sites More sharing options...
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