stumbles for some reason? (Page 2/4) katie80 AUG 29, 12:41 AM I've also been having another issue. it seems to be a more recent one. when I start the engine and it's hot and it dies immediately unless I rev it. once I start driving it's fine again. it doesn't do that when it's cold. not a huge deal but if anyone would know off the top of their head. Xenoblast AUG 29, 03:04 AM quote Originally posted by katie80: I've also been having another issue. it seems to be a more recent one. when I start the engine and it's hot and it dies immediately unless I rev it. once I start driving it's fine again. it doesn't do that when it's cold. not a huge deal but if anyone would know off the top of their head. You should check the ignition timing of the engine. katie80 AUG 29, 03:35 AM quote Originally posted by Xenoblast: You should check the ignition timing of the engine. did that a couple weeks ago. it's right on the money. (did it in service mode or whatever as described on the sticker.) Xenoblast AUG 29, 12:40 PM quote Originally posted by katie80: did that a couple weeks ago. it's right on the money. (did it in service mode or whatever as described on the sticker.) What did you replace 2 weeks ago that fixed the problem? Perhaps you bought cheap components and they broke already, that has happened to me a lot. It never has happened with my ac delco parts however katie80 AUG 29, 02:08 PM quote Originally posted by Xenoblast: What did you replace 2 weeks ago that fixed the problem? Perhaps you bought cheap components and they broke already, that has happened to me a lot. It never has happened with my ac delco parts however I meant I set the timing with a timing light. never done it before but it was pretty easy. I replaced the fuel pump, injector, filter, regulator, breather filter and pcv valve, and cleaned the gas tank. the issue only started earlier this week. it was totally fine until earlier this week. like I said earlier I drove the same highway I was on (to the same destination even) and it was fine. I drove home and didn't do anything and drove that highway again when it did the thing. I have a feeling it's the ignition coil. its sorta beat up looking and is certainly the original. I read somewhere that those are prone to failing on fieros. It really only died for what felt like a few revolutions of the engine, just kept doing it every few seconds til I let it idle down. Xenoblast AUG 30, 04:00 PM Yea id replace all the ignition components either way, like the coil, icm, pickup coil, maybe even the sparkplugs and wires. Also i may be blind, but I dont think you said you checked the fuel pressure yet. check it while its primed but off, and also when its running. perhaps because it only happens while cruising it has something to do with the egr or even the ecu. this probably isnt your problem but i remember once my engine would shut off for 1/2 a second whenever i pressed on the breaks or turned up the radio. i fixed it by cleaning the battery terminals and putting some dielectric grease on it. perhaps do the same with your battery and ground. You could also try adding an new ground strap, alongside the stock one somewhere on the engine sorry for suggesting a shotgun approach lol katie80 AUG 31, 12:01 PM quote Originally posted by Xenoblast: Yea id replace all the ignition components either way, like the coil, icm, pickup coil, maybe even the sparkplugs and wires. Also i may be blind, but I dont think you said you checked the fuel pressure yet. check it while its primed but off, and also when its running. perhaps because it only happens while cruising it has something to do with the egr or even the ecu. this probably isnt your problem but i remember once my engine would shut off for 1/2 a second whenever i pressed on the breaks or turned up the radio. i fixed it by cleaning the battery terminals and putting some dielectric grease on it. perhaps do the same with your battery and ground. You could also try adding an new ground strap, alongside the stock one somewhere on the engine sorry for suggesting a shotgun approach lol I've replaced the plug wires and plugs, they have less than 2.5k miles on them. I didn't check the fuel pressure with the new pump, as it is a brand new pump. I don't think it's fuel pressure in the slightest as I was just experiencing a fuel pressure issue and it was TOTALLY different. if I accelerated hard it would stumble a whole lot til it got it together and if I was cruising it would start to stumble and wouldn't stop til I lowered the revs (same fix, different issue). it would also throw a check engine light after the 50 seconds for lean fuel condition, not so with my current issue. the battery terminals are also very clean, the positive is kinda janky because it must've been broken at one point (previous owner was an idiot) but the ground is clean and the strap is fresh (I replaced it when the engine was out). it was one of the things I didn't skip (skipped the AC compressor and the oil pan gasket, both bit me in the ass. ac because I am actually a tiny little baby and it gets up to 95 here in summer. it's fine though because my other ac evaporator popped and needs to be replaced so now neither of my cars have ac.) I'm really sick of fixing my fiero, I'm just gonna replace the ignition coil and see if it helps. it's cheap enough and mine looks pretty old and ratty. katie80 SEP 03, 10:24 AM quote Originally posted by Xenoblast: Yea id replace all the ignition components either way, like the coil, icm, pickup coil, maybe even the sparkplugs and wires. Also i may be blind, but I dont think you said you checked the fuel pressure yet. check it while its primed but off, and also when its running. perhaps because it only happens while cruising it has something to do with the egr or even the ecu. this probably isnt your problem but i remember once my engine would shut off for 1/2 a second whenever i pressed on the breaks or turned up the radio. i fixed it by cleaning the battery terminals and putting some dielectric grease on it. perhaps do the same with your battery and ground. You could also try adding an new ground strap, alongside the stock one somewhere on the engine sorry for suggesting a shotgun approach lol I replaced the ignition coil and it did not fix the problem. how would I actually diagnose it. katie80 SEP 03, 01:06 PM quote Originally posted by Xenoblast: Yea id replace all the ignition components either way, like the coil, icm, pickup coil, maybe even the sparkplugs and wires. Also i may be blind, but I dont think you said you checked the fuel pressure yet. check it while its primed but off, and also when its running. perhaps because it only happens while cruising it has something to do with the egr or even the ecu. this probably isnt your problem but i remember once my engine would shut off for 1/2 a second whenever i pressed on the breaks or turned up the radio. i fixed it by cleaning the battery terminals and putting some dielectric grease on it. perhaps do the same with your battery and ground. You could also try adding an new ground strap, alongside the stock one somewhere on the engine sorry for suggesting a shotgun approach lol I'll start replacing ignition components if this video doesn't help with anything. https://youtu.be/MjsGA54mvT4 I just took this, it lurches when I let off the throttle while I'm cruising. it started doing it at low speeds too. Xenoblast SEP 03, 01:23 PM quote Originally posted by katie80: I replaced the ignition coil and it did not fix the problem. how would I actually diagnose it. For the pickup coil, test the resistance between the two contacts, it should be between 500-1500 ohms. if not, replace. also make the the magnet is in good condition. I couldnt find out how to test the icm for the 84 i4, seems to be specific for that year. if its the pickup coil unfortunately youll have to pull the distributor out to replace it. oh and also check the sparkplugs to see if they have any clues to whats going on, and also check the gap.