Back fire, hard start, possible over heating?

[Dsobes]

Okay so I swapped out my injectors for smaller ones (since the chip I have isn't tuned for bigger injectors), cleaned the icv and cold start injector, and a new wiring harness for the engine as well and a new fuel pump. Car won't turn over very well, I have to use starter fluid to get it to run sometimes. It's idle is irratic, pedal response isn't always accurate. I'll floor it and it will slowly accelerate. It started back firing today , and stalling...I think the valves are out of adjustment as well. Any idea's?

[jlevie]

I'm thinking that you have intake leaks and/or a possible fuel system problem. A smoke test will quickly tell if there are any intake leaks and were they are. The Bentley manual has a suite of fuel system tests.

[Dsobes]

Thank you, I'll check that out. Your always helpful jlevie!

[Dsobes]

Okay. I also had a different battery in the car, I'm charging the old one...I'm afraid to start the car after how it ran. There has also been injector cleaner sitting in the gas tank since i haven't been able to drive it, along with dry gas. Would this ruin some of the engine components possibly. Also is there a way to smoke test at my house as I know how vacuum sensitive these engines are and DO NOT want to fuck my car up even more.

[tonywonder]

i dont think the fuel additive will harm the engine. are you sure that switching the injectors was the right idea? how much bigger were they than stock?

[Dsobes]

Lol the previous owner had 19lb ford shit in there. I put in 17lb ones from my old 325is... And actually it literally does nothing tony, the computer will re figure out how much gas to squirt out after 500ish miles so it's as if there are 14lb ones in there. The only way to make this "harmful" is if I were to tune the engine to use larger ones and forced way too much gas in. This is actually making the car run worse (lean) but these injectors are higher quality, and have less flow so technically I'm helping my car get back to stock more. It has a Dinan chip which isn't tuned for larger then stock injectors as well. The 19's were pooping out. I don't know much about these engines per say but I do understand the way the DME works. I read up on it, it's either the stuff jlevie said, or my 02 sensor/valves needing adjustment/water temp sensor/ water temp switch. I also noticed today, after turning up the ICV a few weeks ago (when weather was warmer) that it's trying to idle 200rpm's lower then previous. I'm going to assume that's a side effect of the sensors being bad. I'm going to adjust the valves and put in the new sensors. I really hope the o2 isn't dead seeing as there rather expensive...

[Dsobes]

Okay I adjusted the valves, my temp sender unit is on its way. I don't have access to a smoke machine close enough to my house and don't want to pay for that (There is one at my auto tech school) My spark plugs looked kinda oily when I pulled them out...awesome...I'm going to attempt to test it for leaks using starter fluid, I found a large crack in the breather hose from the top of the valve cover to the intake manifold. Would this cause a vacuum leak or is it just a vent?

[jlevie]

There are plenty of possible intake leaks that can't be detected visually or with carb cleaner. And it doesn't take much of a leak to cause problems. The alternative to a smoke test is to replace every hose, seal, and gasket that cause an intake leak. The complete list
of possible causes of an intake leak is:

Intake boot
Throttle body gasket
ICV hoses & connections
Brake booster, hoses, and connections
Crank case breather hose
Evaporative control hoses, valve, and expansion tank
Fuel pressure regulator & hose
Injector seals
Valve cover gaskets & bungs
Oil filler cap
Dip stick o-rings
Oil return tube o-rings

[Dsobes]

Alright, only reason I won't drive it to school is because my license plate light needs to be rewired. I just fixed my brakes today as well. It isn't inspected so I don't want po po at me. I'll get that smoke test as soon as I figure out what two wired go into the license plate lamp...

[Dsobes]

Smoke testing commences on Thursday. I can't even get it to turn over now or run...I moved the position sensor for the flywheel. It didn't look like it was installed properly. I think that's what the sensor was? It went from my drive pulley right into the diagnostics plug...I put on a new o2 sensor, old one was hella bent so I'm almost certian that is why I wasn't getting any fuel at full throttle... Next I'm going to check the fuel pressure. I checked and re tightened many of the vacuum lines and it seems to turn over a little easier now. So either I have a horrible vacuum leak, my piston rings are shot, my fuel system is fucked, or my head is bad...Either way there shouldn't be oil on the spark plugs. It also appears there is a lot of oil built up on the front of the engine. I may just put the car up for the winter, and rebuild the engine or take it to the local independent bmw shop via flat bed to get it looked at... I tried starting it with starter fluid and it would kick over then stall...

[KenC]

Tps?