1983 320i, having warm start problem; have put new rotor, cap, wires, plugs, air filter, fuel filter, oil change, timing, new rear muffler system, new rear fuel pump with filter, new fuel line. Still having warm start problem, seems like it's starved when trying to start; this morning, small backfire. Could it be the oxygen sensor, or injector problem? Only had car 2 months and prior owner owned since new and she sat in a garage for 5 years. Absolute beauty - HELP ...doing all the research I can. Thanks.
Losing fuel pressure-warm start probs
- Thread starter Maggie9898
- Start date
I left my car with my mechanic for TWO weeks - he finally - I guess through process of elimination, and removing hoses, and working his way backwards, was finally able to "guess" I was losing fuel pressure because the fuel pump wasn't pushing out enough fuel. When he replaced the pump the fuel line went.....but NOW, it's STARVING and I mean STARVING for fuel........I'm going back to my other mechanic tonight......I'm SICK of not knowing and being danced around. I bought a CD with diagnostic/repair capabilities and get it in about a week - I'm sick of these mechanics second guessing........I had wondered if I was getting some kind of vapor lock, or bubbles or air being trapped....when you start her up, she fires, but it's sounds like it's missing, like there's nothing pushing the fuel through the line to stay going. She finally catches, sounds ROUGH, and then clears herself out - like she needed a good cough or couple hard pumps on the accelerator to clear herself out. Will have the bypass valve checked tonight.........I'm so frustrated....
)) thank you
)) thank youAs a fellow owner of an 83 320i that sat for years before I got her running again, I would say thta the single most important reference for troubleshooting fuel problems is the bosch fuel injection book, I forget the exact title. I had the same problems, most of my problems with mine was fuel related. I hate to say it, but you may have to drop the gas tanks. Mine sat for 5 years as well. If there is rust in the tank (probable), then the in tank pump is probably covered in it and not able to suck the fuel out. Thats right, there are 2 fuel pumps. On outside of the tank accesable from underneath the car, the other in the passenger side tank. You should also have a haynes manual or similar. To check for rust with out dropping the tank, you have to remove the bottom seat cushion. Simple, two 10mm socket to remove the two bolts that hold it in place. You should see a flap of insulation covering the access hole. Use a phillips head screw driver to remove the four screws. You should see three hoses and some electrical connections. The hoses have fuel, disconnect them, as well as the electrical (disconnect the batt first!, then elec., then fuel). Then you with need two straight screwdrivers, corss them and place the tips on a tab, use it to un-screw the pump/sender assembly. Carefully remove the assembly, turning it 90 deg. (parallel to the ground) as you pull it up. It has been a while since I have done it, but I have many times, just dont drop anything in the hole. Take a flash light and look into the tank. If you see ANY red/orange at the bottom, you have rust. Hard to tell through gas, but it will not be smooth, also, the pump you just pulled out should have it on the small screen at the bottom of the pump. If it is rusty, you can either drop the tank, clean and rust proof it using chemical from J.C. Whitney, or replace the tanks w/ reman. ones. I did this on my daily driver two years ago and it is still fine. Also, check the voltage going to the external pump. If it is not 12V, have the wiring checked out. This is just one of many possible solutions, however, if this is your problem, and you do not address it now, you will waste tons of $ on new parts, more frequently than you think. Also, if you connect the internal pump to the electrical leads, and turn the ignition to thr run position, you should hear the pump prime itself by running for a few seconds. Then try to start the car (it obviously wont with fuel lines disconnected) and hear/feel if it is working. if it doesn't you may need a new internal pump, esp. if it has been sucking up rust! good luck, I have been restoring/fixing mine since '97, and have a fair amount of knowledge about these problems, they are usually either fuel or electrical.
Thanks for your help
I'm taking her to a BMW import specialist Friday morning; I keep leaning toward it being the FPR or the accumulator, and my last thought was the fuel tank relay in the main tank. I agree there may be an accumulation of rust - so let's see what he comes up with. I buy all my own parts, as that is the most efficient way to restore her but only two of my mechanics will install them. She's running slightly rough - which tells me it's bogging down somewhere between the back pump and the injectors. So let's see what he comes up with tomorrow. Thank you SO much for taking time. I'm going to ask him tomorrow about rust build-up in the tank and you have given me food for thought. Oh BTW, I have a Haynes manual on its way as we speak. Just bought her on Ebay....and Bavarian auto also suggested I buy their manual, specifically addressing the injection issues on the 300 series. Believe it or not, I love the car and just wanna figure out what's going on....I drive my mechanics crazy with questions....they don't like "girls" throwing mechanical terms at them....maybe I should just stand there and play blonde....
NAH!!!!!!!!!!!!!!! Will keep you updated. Thank you again.
I'm taking her to a BMW import specialist Friday morning; I keep leaning toward it being the FPR or the accumulator, and my last thought was the fuel tank relay in the main tank. I agree there may be an accumulation of rust - so let's see what he comes up with. I buy all my own parts, as that is the most efficient way to restore her but only two of my mechanics will install them. She's running slightly rough - which tells me it's bogging down somewhere between the back pump and the injectors. So let's see what he comes up with tomorrow. Thank you SO much for taking time. I'm going to ask him tomorrow about rust build-up in the tank and you have given me food for thought. Oh BTW, I have a Haynes manual on its way as we speak. Just bought her on Ebay....and Bavarian auto also suggested I buy their manual, specifically addressing the injection issues on the 300 series. Believe it or not, I love the car and just wanna figure out what's going on....I drive my mechanics crazy with questions....they don't like "girls" throwing mechanical terms at them....maybe I should just stand there and play blonde....
NAH!!!!!!!!!!!!!!! Will keep you updated. Thank you again.
For anyone with fuel pressure problems
After doing some research and learning more about the 300 series of Beemer, my first concern was that my fuel pump in the main tank may have died putting undue pressure on my exterior pump. First mechanic said, no way....finally found out Friday the main pump IS dead, my prior mechanic put the wrong pump in her, so replacing both today. Also having fuel pressure check done to see if that resolves the warm start, but I still think the FPR and accumulator may be the culprits as well. Three mechanics and I'M the one who had to say - check my main pump.....which is why research is GREAT.....the more you know, the less they like you, but educated is better than broke.
Wish there were more girls on this forum - women need to be more informed about their cars and their engines.......it's a gas!
After doing some research and learning more about the 300 series of Beemer, my first concern was that my fuel pump in the main tank may have died putting undue pressure on my exterior pump. First mechanic said, no way....finally found out Friday the main pump IS dead, my prior mechanic put the wrong pump in her, so replacing both today. Also having fuel pressure check done to see if that resolves the warm start, but I still think the FPR and accumulator may be the culprits as well. Three mechanics and I'M the one who had to say - check my main pump.....which is why research is GREAT.....the more you know, the less they like you, but educated is better than broke.
Wish there were more girls on this forum - women need to be more informed about their cars and their engines.......it's a gas!
okay - now I KNOW I've lost my mind....I took my 320i to three mechanics with the warm start problem - one of whom was an import specialist - yeah, right....two fuel pumps and fuel line later - my warm start problem is still there. I asked if the accumulator may be the culprit - NOPE he said....paid $1100 for new pumps, lines, vacuum hoses and timing. Well, I said ENUF is ENUF this weekend.....went to a beemer specialist this morning and said, PLEASE check the accumulator - my prior three guys said it's not the problem..YUP YUP
he pulls the line, crimps her off, and lo and BEHOLD people.....we have fuel spurting out - obviously the diaphragm is shot..............gee.........YA think.............the guy even knows my other mechanic - and tried to keep his mouth shut - so, NOW - $2000 later - FINALLY I found a mechanic who agreed with me, took me under the rear end and showed me how the accumulator was bleeding off fuel.........what sickened me is, of course, the accumulator is right NEXT to the NEW fuel pump just installed last week........
amazing........utterly amazing!!!!! I need to write a book about women and cars.....I'd be wealthy................
he pulls the line, crimps her off, and lo and BEHOLD people.....we have fuel spurting out - obviously the diaphragm is shot..............gee.........YA think.............the guy even knows my other mechanic - and tried to keep his mouth shut - so, NOW - $2000 later - FINALLY I found a mechanic who agreed with me, took me under the rear end and showed me how the accumulator was bleeding off fuel.........what sickened me is, of course, the accumulator is right NEXT to the NEW fuel pump just installed last week........
amazing........utterly amazing!!!!! I need to write a book about women and cars.....I'd be wealthy................