Jump to content
  • When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Rough start and violent engine shaking after exhaust...


BDB

Recommended Posts

Hi guys,

Looks like my follow up question in my original thread here is getting buried: http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/t,383328/

So after I installed a replacement exhaust manifold and re-installed my old downpipe, I made sure that I reinstalled all my vacuum hoses that I temporarily unhooked. Now she doesn't start. But doesn't start is a mild statement. What's happening is this:

- I fully depress the clutch. I turn the key and it doesn't turn over. It makes that sound like as if you cranked the ignition when the engine is actually running (you know you've all done it once in your life ;) )

- after trying to turn the engine over the first time, the second time it turns over but then the engine shakes to all hell and cuts off.

- there is some residual fuel spillage, not much but enough to notice.

- I triple checked to make sure that all the vac hoses I unplugged were correctly plugged in. I even removed my vac gauge hose just in case.

Note: my 02 did run well prior to removing the busted exhaust manifold.

Possible causes: could any of these be it?

- Is it possible that the exhaust manifold is not properly tightened down, causing this rough stumbling? same too with the downpipe tightening?

- Could I have done some damage somewhere by improperly installing the exhaust studs? Man that would not be good. The replacement studs I had did not have the middle shoulder that keeps the stud from stopping. what would happen if I tightened them down too far with the nut? Would it puncture anything and that is the cause of this non-starting?

Thanks gents, I'm mildly freaking out. I'm going to remove the air filter and poke around again.

Link to comment
Share on other sites

Truth is that an engine will run well enough, although loudly (without violently shaking), even without a header installed. I suspect your problem is unrelated to the exhaust and that you accidentally knocked something out of adjustment. Thinking about the passenger side of the engine, is it possible your distributor wasn't tightened properly and you knocked it out of adjustment? did you happen to disconnect a spark plug lead that you forgot to reattach or did you possibly connect them incorrectly? How are your points? rotor? or is the ignition non-stock?

No chance of damage from improperly inserting studs unless if you were trying to torque them in with an impact driver, and then even then you'd likely just have pulled thread or broken stud... nothing that would alter the way the engine runs.

Double check all ignition stuff first. then double check intake and fueling... perhaps the old header was so clogged up that the newly increased flow meant the carb settings are all off; unlikely but not unheard of.

Post back... work through it systematically.

1974 Grey European Market BMW 2002 

1976 Yellow BMW 2002 "GOLDENROD" SOLD

1972 Yellow Austin Mini 1000

A bunch of Bikes...

Link to comment
Share on other sites

Check and see if the starter worked itself loose. Suggest you disconnect the battery cable first.

And then look closely at the distributor and firing order/timing.

GL,

Ray

Stop reading this! Don't you have anything better to do?? :P
Two running things. Two broken things.

 

Link to comment
Share on other sites

Hi,

if you removed the distributor cap it may be

installed 180 degrees off. i think that if you used

replacement exhaust studs, you may have run them

in so far that they are hitting the exhaust springs

or the retainers for the valves. remove the head cover

and look at the exhaust valves. if the studs are holding

the valves down you may have more problems in

the from of piston to valve interference. the reason the

motor may be shaking is that the pressure in side

the cylinders is fighting the pistons. check that and post

your info.

good luck

stone

stone racing co

phila pa 19123

Link to comment
Share on other sites

Truth is that an engine will run well enough, although loudly (without violently shaking), even without a header installed. I suspect your problem is unrelated to the exhaust and that you accidentally knocked something out of adjustment.

Oh this is good news. I will check though to see if the studs went too far as another member mentioned below

Thinking about the passenger side of the engine, is it possible your distributor wasn't tightened properly and you knocked it out of adjustment?

when i removed the plugs from the pass side of the engine, i am pretty confident I put them back in the right order. I have a Petronix ignitor (came with the car) and I didn't remove the cap. It is entirely possible that I knocked the hell out of it while trying to remove the exhaust manifold itself. I read a post here on FAQ about the order of the plugs coming out of the top of the cap and I believe I got it right. Man I wish i saved the url! But there was reference to the mark on the housing that indicates how you should position the cap properly to determine what is plug wire #1, 2, 3 and 4. I'll post up a pic tonight

did you happen to disconnect a spark plug lead that you forgot to reattach or did you possibly connect them incorrectly? How are your points? rotor? or is the ignition non-stock?

I did remove and reattach them. I will post up a pic soon. I am really unfamiliar w/ the ignition system on this car other than to say I have a Petronix. Not even sure the model #.

No chance of damage from improperly inserting studs unless if you were trying to torque them in with an impact driver, and then even then you'd likely just have pulled thread or broken stud... nothing that would alter the way the engine runs.

I loctited the studs first. I kept most of the studs intact as they did not come out and those had shoulders. The replacement ones I got did not have shoulders. I believe 2 of them started to turn with the nut, but I compensated for that. I will remove the valve cover and look inside as one member suggested to see if any of them went too far. But ignition system first!

Double check all ignition stuff first. then double check intake and fueling... perhaps the old header was so clogged up that the newly increased flow meant the carb settings are all off; unlikely but not unheard of.

Post back... work through it systematically.

I'll check ignition first and then fueling. Thanks for the great advice

Link to comment
Share on other sites

The cap only goes on one way. If you are starting from scratch, get the motor to TDC, and the rotor will be pointing more or less at where the number one plug wire goes (or should go) on the cap. From there, follow the firing order (usually clockwise). Pertronix doesn't enter into this process.

Link to comment
Share on other sites

Thinking about the passenger side of the engine, is it possible your distributor wasn't tightened properly and you knocked it out of adjustment? did you happen to disconnect a spark plug lead that you forgot to reattach or did you possibly connect them incorrectly? How are your points? rotor? or is the ignition non-stock?

Ok, I had a little time today to check the ignition system. I think I found one boo boo. But first, I wanted to make sure nothing was loose on the top of the distributor cap and wires. Everything was tight. The clips were both fastened down tight. All 5 wires on top of the dist cap were pushed down tight. Just to be 100% sure, I did a little homework to make sure I got the plug order right off the dist cap and to the plugs themselves. They were all correctly plugged in.

What I did find off is I may have switched two wires on the coil (corrected, thanks guys). See the pic attached. There's a double ground (I believe its ground) coming from somewhere and I attached it to the positive male spade connector. I believe that one should be going to the "15" connector. Can someone confirm?

Double check all ignition stuff first. then double check intake and fueling... perhaps the old header was so clogged up that the newly increased flow meant the carb settings are all off; unlikely but not unheard of.

Post back... work through it systematically.

Didn't get around to checking the intake or the fueling. I did notice though that the butterfly valve in the carburetor was not flat or pointing vertically. it was in a 45 deg position. could that be a cause too? i dont recall ever knocking it.

i'm so bad with this car, its ridiculous. thanks guys for all your help.

post-19655-13667671514583_thumb.jpg

post-19655-13667671523449_thumb.jpg

Link to comment
Share on other sites

Check and see if the starter worked itself loose. Suggest you disconnect the battery cable first.

And then look closely at the distributor and firing order/timing.

Ray,

The starter is fixed very tight to the body. the only thing i found that was a problem was i believe i incorrectly switched two wires. also, the center cable was so loose. I think the inner connector part needs to be tightened up or else I'll just buy a new cable.

As far as the firing order, I have a Pertronix Ignitor, I am not sure how to check firing order/timing.

Link to comment
Share on other sites

The part you are referring to is the COIL not the STARTER. Absolutely the main lead being loose and those wires being switched could cause the issues your describing.

1974 Grey European Market BMW 2002 

1976 Yellow BMW 2002 "GOLDENROD" SOLD

1972 Yellow Austin Mini 1000

A bunch of Bikes...

Link to comment
Share on other sites

And number 1 wire position on the cap has to be roughly over the copper tip on the rotor at TDC. If you are in any doubt as to where the #1 wire was on the cap before, get engine to TDC and check. You may wish to invest in a shop manual.

Link to comment
Share on other sites

The part you are referring to is the COIL not the STARTER. Absolutely the main lead being loose and those wires being switched could cause the issues your describing.

Yikes. Yes, looks like i should buy a manual asap. I'll give it a go, see what happens.

Thanks,

Bob

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • BMW Neue Klasse - a birth of a Sports Sedan

    BMW Neue Klasse - a birth of a Sports Sedan

    Unveiling of the Neue Klasse Unveiled in 1961, BMW 1500 sedan was a revolutionary concept at the outset of the '60s. No tail fins or chrome fountains. Instead, what you got was understated and elegant, in a modern sense, exciting to drive as nearly any sports car, and yet still comfortable for four.   The elegant little sedan was an instant sensation. In the 1500, BMW not only found the long-term solution to its dire business straits but, more importantly, created an entirely new
    History of the BMW 2002 and the 02 Series

    History of the BMW 2002 and the 02 Series

    In 1966, BMW was practically unknown in the US unless you were a touring motorcycle enthusiast or had seen an Isetta given away on a quiz show.  BMW’s sales in the US that year were just 1253 cars.  Then BMW 1600-2 came to America’s shores, tripling US sales to 4564 the following year, boosted by favorable articles in the Buff Books. Car and Driver called it “the best $2500 sedan anywhere.”  Road & Track’s road test was equally enthusiastic.  Then, BMW took a cue from American manufacturers,
    The BMW 2002 Production Run

    The BMW 2002 Production Run

    BMW 02 series are like the original Volkswagen Beetles in one way (besides both being German classic cars)—throughout their long production, they all essentially look alike—at least to the uninitiated:  small, boxy, rear-wheel drive, two-door sedan.  Aficionados know better.   Not only were there three other body styles—none, unfortunately, exported to the US—but there were some significant visual and mechanical changes over their eleven-year production run.   I’ve extracted t
  • Upcoming Events

  • Supporting Vendors

×
×
  • Create New...