Half second ignition cuts and stalling

[billythekid]

You would be a fool to not take the advice of me and Forced Firebird, as we have worked on and fixed many hundreds of E30s and have been participating on this forum for over a decade.. If you believe the AFM will not cause violent non stop bucking after both he and I explained it to you, then its probably best you pay a professional mechanic to fix your car or sell your car.

See my article on the topic of AFM's, as you can clearly see. When the signal output has a huge voltage drop, the DME thinks the amount of air entering the combustion chamber to be significantly less, thus the fuel is cut off significantly. This will result in sudden and brief power loss, or bucking. https://www.r3vlimited.com/board/for...afm-s-for-sale

I think what I'm going to do from here is just convert it to a single pump and just not let the tank run low anymore. It's just difficult cuz on top of going to school I have to drive to work almost every day and gas is getting more and more expensive

[ForcedFirebird]

Gregs///M Not sure he wasn't taking the advice, but is frustrated. It's so difficult to grasp emotions via text on a forum lol. Based on the lack of punctuation, sentences and run-on paragraph, it's frustration in the car. Thanks for the kind words :)

billythekid Since you swapped the AFM for the old one with no change, the AFM doesn't sound like the MAIN culprit. There are two more items that drastically change fuel delivery. You ddn't state what year your car is, but the later ones have a round plug under the throttle body for the injectors and coolant sensor. (easily identified if there's a long plastic rail that plugs all 6 injectors at once). This plug catches all the oil drippings from the TB, is susceptible to moisture intrusion, so the pins get very green/dirty and that corrosion travels along the copper wire strands. The plug acts like the o2 plug, it twists off - pull it apart and check the pins, the female side usually is the worst (engine side of harness). This connector carried the signals for the injectors to fire, as well as relay the engine temp to the ECU and dash gauge. when they go bad, all kinds of weird things happen. If the pins looks good, don't dismiss the wiring, the rubber boots peel off the connectors and expose the wires where they are crimped into the pins. If you see green/white chalky residue there, I would bet it's the favorite c191 connector symptoms

[ForcedFirebird]

It's not the air flow meter. After that whole shit show I ended up putting gas in the tank and poof works perfectly. Now putting more gas in it had never made anything better before. And I doubt it was bad gas. But now it's just whenever the tank gets low I have the issue. I was going to buy a afm money was tight but I had to do the alternator first. I'm pretty sure the symptoms of when it's low it seems to starve means fuel pump

You posted at the same time as me. After this post, I will say your tank is rusted on the inside, clogging the fuel pump sock, fuel filter, injector screens, and probably even ruined your fuel regulator if it's been running like this for any length of time.

[billythekid]

You posted at the same time as me. After this post, I will say your tank is rusted on the inside, clogging the fuel pump sock, fuel filter, injector screens, and probably even ruined your fuel regulator if it's been running like this for any length of time.

Well I'm ordering the single pump kit this friday along with a few misc. Things I guess I'll drain it and see if I can't vacuum a bunch of junk out. There definitely has been water in the fuel in the past which I've gotten past so maybe it is pretty nasty in there. Thanks for the responses from both of you guys along the way though it means a lot. I've been having this issue for about a year but never worried so much about it until it seemed to progress to something worse. When it has a good amount of gas in it it runs amazing. After it cutting out for the past year it really teaches you to appreciate being able to put your foot in it and the car doing what it's supposed to

[ForcedFirebird]

Well I'm ordering the single pump kit this friday along with a few misc. Things I guess I'll drain it and see if I can't vacuum a bunch of junk out. There definitely has been water in the fuel in the past which I've gotten past so maybe it is pretty nasty in there. Thanks for the responses from both of you guys along the way though it means a lot. I've been having this issue for about a year but never worried so much about it until it seemed to progress to something worse. When it has a good amount of gas in it it runs amazing. After it cutting out for the past year it really teaches you to appreciate being able to put your foot in it and the car doing what it's supposed to

New tanks are like 200 clams. The dual pump system works fine, but the in-tank portion is expansive since you need to purchase the entire basket (low pressure, high volume). Not sure which kit you purchased, but make sure the line that replaces the 12mm from tank to current pump is rated for fuel injection - the stock hose is NOT, it's just carburetor fuel line.

If you have the late model with the plastic rail connector like I mentioned earlier, will also mean the return and supply are on the same side of your fuel rail. That being said, rust tends to collect in these type of fuel rails, near #6 cyl, so be sure to clean all the hard/soft lines, fuel rail, regulator, and even pull injectors and at least blow out the supply side as there will be collected sediment there. Ask me how I know? lol BTDT

[ForcedFirebird]

Oh, to add. There may have not been water in your tank to start, but today's fuel is up to 10% ethanol, which is hygroscopic - which means it will collect moisture from the atmospheric conditions and deposit them in your fuel tank until there's more water than alcohol - both of which speedily rusts raw steel (what the e30 tank is made of). With the e36, BMW started with plastic tanks and SS lines, so they were already prepared for e10, the e30 was not - and in fact, if you read your owner's manual, it warns against anything more than e10. If you have the ability, use rec90 in your e30 (pure gasoline).

[billythekid]

Oh, to add. There may have not been water in your tank to start, but today's fuel is up to 10% ethanol, which is hygroscopic - which means it will collect moisture from the atmospheric conditions and deposit them in your fuel tank until there's more water than alcohol - both of which speedily rusts raw steel (what the e30 tank is made of). With the e36, BMW started with plastic tanks and SS lines, so they were already prepared for e10, the e30 was not - and in fact, if you read your owner's manual, it warns against anything more than e10. If you have the ability, use rec90 in your e30 (pure gasoline).

Thanks for the advice. I've read a few write ups about the tre340 kit I was just going to go with that. Only reason being is because I can't find the low pressure pump sold by itself. So 70 dollars seems like a much better way to spend my money. Which I don't have a lot of. Otherwise I would have gone and bought the afm just like you guys suggested. And on the fuel thing I've never put ethanol mixed gas or whatever you want to call it. There's always a chance there's water in it but unlikely. But with the extreme temperature changes it's entirely possible there was some condensation. If the tank is rusted I'll look at buying a clean used one but it all depends on whether I can or can't afford it at that time. If I had another car or if my bike was street legal I wouldn't mind waiting but my parents won't let me get another car and trying to get a old yamaha dirtbike street legal has proven difficult simply because the registering process. I'm just happy I fixed a few major issues along the way of finding the main culprit. I'm going to order a new fuel pump relay too because the contacts are charred and I'm gonna put some dielectric grease on the pins. Should be good for as long as I need it to be

[billythekid]

Update. Fuel pump isn't issue it's the sparkilator leads arcing out. I guess the sensors an relays etc didn't like it and it went haywire. Saw the arcs but electrical tape is working as a temporary bandaid for now