BayAreaZT Posted April 1, 2003 Share Posted April 1, 2003 I was driving to the store last night and all of a sudden I get a really big backfire. I pulled over to check things out and it would idle fine but if I would give it any gas it would just stumble and backfire alot. If I turned the engine off, it would started up again fine but eventually it would not start anymore. I didn't have a flashlight so I didn't get to check everything out. I'm going to check if I'm getting any spark today. I don't think it's the fuel pump cause I can hear it turn on. What else should I check for? Could it be an AFM problem or TPS? Is it possible for the timing to get thown off all of a sudden? Quote Link to comment Share on other sites More sharing options...
Tim240z Posted April 1, 2003 Share Posted April 1, 2003 Maybe a sticky EGR valve? Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 1, 2003 Share Posted April 1, 2003 there are so many things this could be, i've been chasing these gremlins for months. Have you checked your coil? The coil could be goin bad. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted April 2, 2003 Author Share Posted April 2, 2003 Checked the coil and I'm getting spark. It may be a fuel delivery problem but I doubt its the filter cause this happened all of a sudden. I'm thinking it's some kind of electrical gremlin. Is there any way to test if the ECU is bad? Quote Link to comment Share on other sites More sharing options...
72zcar Posted April 2, 2003 Share Posted April 2, 2003 vacuum leak perhaps Quote Link to comment Share on other sites More sharing options...
Tim240z Posted April 2, 2003 Share Posted April 2, 2003 Dale, Don't rule out the EGR valve. i had a very similar problem recently with my 83 ZXT. Went out and pulled it into the driveway....everything cool. Came back an hour later and fired it up again to do a tune up, and it started hard, and idled very low, almost stalling. I was convinced it was a vacuum leak. Spent an hour tracing vaccum lines. I finally pulled off the vacuum line from the EGR valve and closed it with my thumb. The idle tone changed! (huh???) So then I replaced the line on the valve and tapped the top of it with a wrench. The idle cleared up and the car has run smoother that ever before since. Tim Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 2, 2003 Share Posted April 2, 2003 just cuz you're gettin spark doesnt mean the coil is good. I get spark, but i still think my coil is bad. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted April 4, 2003 Author Share Posted April 4, 2003 Finally got to work on the car today and I found the problem. I took the distributer cap off hoping it was something simple and sure enough it was the rotor. The screw holding the rotor came off so the rotor wasn't spinning. There was also a problem with the fuel pump that I traced back to a bad ground. Seems to be running fine now but I havn't ran it hard yet. Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 4, 2003 Share Posted April 4, 2003 where'd you find the bad ground? how'd you know it was the fuel pump? You coming to rio vista? Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted April 4, 2003 Author Share Posted April 4, 2003 I knew it was the fuel pump cause I couldn't hear it turn on when I turned the ignition on. I cleaned the connectors and noticed the ground wire coming out of the harness from the fuel pump was was loose where it was attached to the frame. So I tightened it and kind of wiggled it back and forth so it would get good contact. I'm probably gonna change my coil anyways and rewire the fuel pump with a thicker gauge wire. I'm gonna try and make it to Rio Vista around 1:00. I'm going to check out a car with one of my buddies in the morning. Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 4, 2003 Share Posted April 4, 2003 well, Ill be headed out there early, so I'll probably be leaving around 2. Ill check out my fuel pump ground as soon as i get downstairs. perhaps sand off the area for better contact. Although Im sure its coming on. Quote Link to comment Share on other sites More sharing options...
MAYHEM Posted April 26, 2003 Share Posted April 26, 2003 Ill check out my fuel pump ground as soon as i get downstairs. perhaps sand off the area for better contact. Although Im sure its coming on. Hey livewire23, did you find out what was causing you grief ? Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 26, 2003 Share Posted April 26, 2003 ah, forgot to follow up, I took off the fuel pump and regulator, cleaned them all out, and then I blew compressed air through the lines to the tank. Basically I think the fuel pickup in the tank was clogged, because after some careful cleaning of everything, when I reassembled it all, It fired up and ran all the way to redline no problem. Quote Link to comment Share on other sites More sharing options...
MAYHEM Posted April 27, 2003 Share Posted April 27, 2003 I'm in the same boat, fuel pump works fine, but it's not pushing any gas. When I removed the fuel line from the filter only fuel foam came out when the pump was running. Most likely I'm going to drop the tank and go thru everything and clean itr out. Since this was the first time my '77 has been cranked since '99. Thanks for your response. Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 27, 2003 Share Posted April 27, 2003 I managed to get by without dropping the tank. Thanks to the miracles of compressed air. Although my pump was pumping a bit of something, it just wasnt flowing enough to keep up the pressure at high RPMs. You might want to clean out the pump too. The gas can get gunked up in there too. If this is your first cleaning since 99, you should probably drain the tank and clean anything that the fuel goes through. I'd even go so far as to pull the injectors and give them a alchohol and propane flame bath. g'luck. oh, one more thing. Something that I found helps, I went to home depot and got some clear vinyl hose to use as fuel line while Im trying to fix the problem. They will corrode out eventually, but so far I've had them on for two months, and they are a great help because I can see where the fuel is, how much of it there is, and what else is in it. Just be sure to clamp em on real tight. They're also a bit hard to fit on, but its well worth it. Quote Link to comment Share on other sites More sharing options...
MAYHEM Posted April 27, 2003 Share Posted April 27, 2003 Thanks you very much, livewire23 for that info. I'll give it shot. If you see a huge mushroom cloud, due east from were you are. I did something wrong. I do have a compressor too. alchohol and propane flame bath. Explain further please Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 27, 2003 Share Posted April 27, 2003 haha. don't drain the tank and use the propane all at once. What I did with the injectors was to pull them all off the fuel rail, and soak the tips in some rubbing alchohol. and then after i dried them off, I took a propane torch and just flamed the end for a little while. Then I hooked them back up to the fuel rail, and they sprayed much better. more even flow. careful if you hook em up to the fuel rail and watch em spray though, you'll get fuel all over. Quote Link to comment Share on other sites More sharing options...
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