What is wrong with my e30?!

[ashton]

I have an 88 325i, 5 speed. It will run fine one minute and then ill turn on to a road or stop at a stop sign or stop light and ill take off and it'll sputter and not have any throttle position. Ill turn the car off and back on and it'll go fine just not for long and it'll do it again. I've replaced the ecu, coil, spark plug wires, spark plugs, rotor button, all new gaskets, coolant temp sensor, afm, fuel pump, fuel filter, o2 sensor, adjusted my valves, 6 new exhaust valves cause I put different head on car cause I broke rocker arms and stuff in old one, new oil filter, new oil, and more stuff. Just can't remember all off the top of my head. I have my exhaust unbolted from the catalytic converter back(im about to bolt it back up) and im so lost on what to do to make my car run right. It took me 4 months to rebuild it and now I've been replacing everything I know. Now im lost and I miss driving my e30 sooooooo much. If you can help me get my car back on the road please help me.

Thanks,
Ashton.

[sweet6e30]

seems to me that once it gets warmed up, it then misbehaves. Im thinking vacuum leaks (rubber expands when warm), but also you have throttle issues, perhapes TPS. If u replaced the head, is your timing correct? Perhaps the bitch tube isnt sealed and seated properly?

i would start by taking some brake cleaner and do some targeted spraying at joints for the intake whilst it idles starting after the AFM, including all around the throttlebody, check out all the little vacuum hoses too for leaks, if your idle increases or dies when u spray a specific place then there is a leak there.

do u get a MIL when it sputters? (stomp test??) misfire? check all your spark plugs for correct gap, and see if they all match with the same electrode color, a light chocolat color is puuurfect. if there is a mismatch on one or two of them check the plugwire and/or injector for that particular cyl

the m20 is a fairly simple motor and more or less bulletproof, there are very little places for things to go wrong in terms of running. 99.9% of the time if its not running right is because of old decreped failed parts, or vaccum leaks. or even "slip of the mind" re-installation ( no offence);)

keep trouble shooting, the fact that u've replaced all these parts is good, keep running down the list.

[ashton]

seems to me that once it gets warmed up, it then misbehaves. Im thinking vacuum leaks (rubber expands when warm), but also you have throttle issues, perhapes TPS. If u replaced the head, is your timing correct? Perhaps the bitch tube isnt sealed and seated properly?

i would start by taking some brake cleaner and do some targeted spraying at joints for the intake whilst it idles starting after the AFM, including all around the throttlebody, check out all the little vacuum hoses too for leaks, if your idle increases or dies when u spray a specific place then there is a leak there.

do u get a MIL when it sputters? (stomp test??) misfire? check all your spark plugs for correct gap, and see if they all match with the same electrode color, a light chocolat color is puuurfect. if there is a mismatch on one or two of them check the plugwire and/or injector for that particular cyl

the m20 is a fairly simple motor and more or less bulletproof, there are very little places for things to go wrong in terms of running. 99.9% of the time if its not running right is because of old decreped failed parts, or vaccum leaks. or even "slip of the mind" re-installation ( no offence);)

keep trouble shooting, the fact that u've replaced all these parts is good, keep running down the list.

What's the bitch tube? Lol. And thanks for all the info. I unplugged the tps while it was running and nothing changed. Is that a problem? And also im gonna check my timing and re adjust my valves. Thanks again.

[matt0300]

Check ur eccentrics, had the same symptoms turned out that 2 of my eccentrics snapped off but didn't break the rocker arm.

[ashton]

Check ur eccentrics, had the same symptoms turned out that 2 of my eccentrics snapped off but didn't break the rocker arm.

How do you check them? Like what do I need to look for? Thanks.

[matt0300]

When u pull ur valve cover ull see ur 12 rocker arms, at the tip of those is a circle piece of metal. Those are ur eccentrics

[ashton]

When u pull ur valve cover ull see ur 12 rocker arms, at the tip of those is a circle piece of metal. Those are ur eccentrics

What do i need to look for that could be wrong?

[sweet6e30]

if they r still there solidly held in place and not missing or snapped. BUT you said you adjusted ur valves so your fine in that department!

[jlevie]

Pull the fuel pump and check to see if there is a layer of rust in the bottom of the tank. Rust being stirred up by sloshing fuel and collecting on the pump inlet screen (and thus starving the pump) would be consistent with the problem description. When you shut the car off, the suction holding the rust on the screen goes away and the rust falls off.

[ashton]

Pull the fuel pump and check to see if there is a layer of rust in the bottom of the tank. Rust being stirred up by sloshing fuel and collecting on the pump inlet screen (and thus starving the pump) would be consistent with the problem description. When you shut the car off, the suction holding the rust on the screen goes away and the rust falls off.

How do I get rid of the rust without replacing/removing the tank? And thanks for the info.

[jlevie]

How do I get rid of the rust without replacing/removing the tank? And thanks for the info.

If the tank has rust your choices are to replace the tank or acid clean and seal it. Either way the tank has to come off the car.

[ashton]

If the tank has rust your choices are to replace the tank or acid clean and seal it. Either way the tank has to come off the car.

Dang that sucks.

[jlevie]

Well, it sounds worse than it actually is. The entire job or cleaning and sealing the tank can be done over a weekend if you drop the tank Friday evening and clean seal it on Saturday. It will be ready to go back in the car Sunday evening. If you replace the tank it will take less time, though the tank will cost a fair bit more than what it will cost to clean and seal it ($60-70 in materials).

[matt0300]

Not really I thought the same thing cause it happened right after I adjusted them (0.010)