Help my car is messed up top speed of 45 mph!

[bchslax99]

Hey so my 1974 2002tii is running horrible...Everyone says its my fuel injectors need to be rebuilt, but a Mechanic at BMW who worked on 2002tii new said they jsut need cleaning?

Symptoms-

Wont go over 3000 RPM

Wont go over 45-50MPH in 4th gear

Runs horrible, seems to be missing

Spark Plugs are constantly fouling and need to be replaced, when i take them out they're as black as coal

Horrible horrible gas mileage maybe 90 miles out of a tank...

Any tips? PLease help

[bchslax99]

17 views no help?

[BLUNT]

tii's are a little more technical and the right knowledgable guy will answer. unless you just want any old info. i can give you some of that

[rho]

I had 2 tii's and if I remember correctly the linkages had to be set up first. That includes the valve on the pump that gives it extra fuel when cold (if that is malfunctioning you can be driving rich).

If you suspect it is the injectors, those are easily removable and you can either clean them yourself of have a shop do it (spray pattern test, cheap).

The fact that you are getting 90mpg per tank tells me you are running stinky rich.

I'm not a mechanic, but there are only 3 things involved here..

Fuel

Spark

Air

How clean is your throttle plate? is it openning 100% at full throttle? another easy thing to check.

Have you run it w/o the air intake ? Maybe something is clogging one of the 2 filters...

Good luck,

Robert

edit.. one other thing.. if the timing is too retarded you will experience those top end problems, and overheating as well.

last note... Ignition wires... check the resistance and make sure they are all within spec. (replace cap and rotor to get those out of the equation)

[_z_]

Have a look at this handy PDF

http://www.thetiiregister.com/pump/index.htm

You should verify that the linkages are in spec and that your warm up transmitter is extending the full 10mm when fully warm. If it isn't your car will run waay to rich and you'll get crappy mileage and crappy plugs.

Check the timing and all the usual tune up stuff too

It could be other things, but if you follow the troubleshooting guide at the back you might get it figured out.

If nothing else print this sucker out and bring it to your mechanic .. it'll help a lot -

best of luck!

PS: running too rich doesn't usually mean it won't go fast or top out ..hmm. It could be running too rich AND have something simple like a plugged fuel filter. So check the fuel filter and screens as well.. those are waaay cheaper than replacing injectors.

[Zenon]

Have a look at this handy PDF

http://www.thetiiregister.com/pump/index.htm

You should verify that the linkages are in spec and that your warm up transmitter is extending the full 10mm when fully warm. If it isn't your car will run waay to rich and you'll get crappy mileage and crappy plugs.

Check the timing and all the usual tune up stuff too

It could be other things, but if you follow the troubleshooting guide at the back you might get it figured out.

If nothing else print this sucker out and bring it to your mechanic .. it'll help a lot -

best of luck!

PS: running too rich doesn't usually mean it won't go fast or top out ..hmm. It could be running too rich AND have something simple like a plugged fuel filter. So check the fuel filter and screens as well.. those are waaay cheaper than replacing injectors.

Listen to _z_!

I'll add that super-rich running could be because the electric cold-start injector may be stuck on (either the thermo-time-switch, control untit, or injector could be at fault) and that is easy to check.

I think it is highly unlikely that the four main fuel injectors are the problem. They would have to be extremely screwed to cause this, even if it made sense that they could (which it doesn't really). In fact the injectors themselves are one of the most reliable parts of the system. Don't even think of blaming the injection pump itself, either, until all other setup and tuning stuff has been checked, re-checked, and tweaked.

Like _z_, if it ran fine but rich before and the onset of problems was fairly sudden (and not after some work being done), I would also suspect a clogged fuel filter or ignition problem. Then maybe a failing fuel pump (not to be confused with the injection pump itself). A quick compression test can help rule out an internal engine problem.

Whatever you do, don't allow yourself to jump to (or accept) expensive conclusions before finding real hard evidence of the problem. Also, if your mechanic is not specifically a BMW 2002tii expert, then I most emphatically suggest finding a mechanic that is! Tiis are not like many other cars ever made, have almost nothing in common with electronic fuel injection from a throubleshooting/repair standpoint, and there is a lot of very specific knowledge required. A "general purpose" professional mechanic, even one specializing in "imports", is probably more dangerous than helpful.

Good luck!

regards,

Zenon

(Edited cause I did not carefully read the problem the first time and jumped to conclusions...)

[Guest Anonymous]

Need more info. Is this problem new or have you been running the car like this for months? Was there any work that was performed on or around the time that your car started running like this?

Without knowing more details all that can be suggested is basics. It would appear that you are running rich therefore you don't have a partially blocked fuel filter however I'd start with general stuff:

Fuel Filter, Fuel Filter, Fuel Filter (I had an E21 that ran like you describe and all it needed was a fuel filter, Check your points - they could be jumping or just off, cap, rotor, plug wires.... Also your cold start/idle valves should be checked. I'm sure someone with a tii can chime in after more details are provided but if something is clogged, stuck open, or has failed it may do that.

you're getting 90 miles per tank? That's like 8mpg!!! WHERE'S IT ALL GOING??? that's like a crappy V-8, you're either running on about 3 to 4 times the fuel or you've got something stuck on all the time. Look at your cold start stuff because something must be stuck on. Do you smell fuel anywhere? Out the exhaust?

Finally, change your oil because if you're running that rich you've smoked your oil. Don't push the car until your fuel milage goes back up to something more reasonable.

[dubois]

and see what happens. Next make sure your car actually achieves normal running temperature, this is important because if it is running cold your warm up regulator is telling the injection pump to run rich. Watch the warmup regulator as the car gets warm, you should be able to see the big washer separate from the lever, if not then you have to correct that. Run those test and report back. Also please post the solution once you solved the problem, most of the time we are left on the dark. Note that the injection system is usually NOT the problem. Something usually precipitated the change, you need to backtrack and think what has taken place recently. Good luck

Also pull the air filter and watch your throtle plate open while you move the gas pedal linkage, watch the entire linkage as it also pulls the lever on the injection pump, it should all be one syncronous movement.

[BillWilliams]

I find tii guys look at and respond to posts with tii in the subject line and visa versa with the carb guys, if neither is in the subject line, take your chances.

Now, all of the post above are spot on. Get the tii tune up manual, available on the tii website, print it out, read it, and follow to the T.

Run through your ignition, points, condensor, plugs, timing.

You will find it. You are really dumping some fuel somewhere but I do not suspect the fuel filter, that usually causes fuel starvation, and a lean condition. However, change that annually.

If this started suddenly, my money is on one of three things:

cold start valve stuck on

warm-up regulator not coming off of warm-up

linkage is binding somewhere on the fuel side

Please report back so all of can learn

[robdelk]

Cold start? stuck open/on

that will do her

[_z_]

I always forget about the cold start injector cos mine is only turned on by a switch !

But none of those rich running problems easily account for the 45mph limit.. thats kind of strange.

anyway, like everyone says check all that stuff and report back!

[Marty]

You should be getting about 1 liter of fuel returned to the tank every 30 seconds. If your fuel presure regulator is plugged you'll get between 80 and 100 psi at the pump and you'll be running way rich, also the cold start injector comes unseated at about 60 psi and will dribble fuel even with the electrical part unplugged. As stated before down load the manual and follow it don't assume anything and you'll find your trouble for sure. You might want to check the air filter also if its clogged up that might acount for your problems also.

[dubois]

I am curious, finding myself learning still everyday. Is that in the injection pump internals?

[BillWilliams]

of the K-pump. I believe it is the piece that the hose, coming out of the K-pump, connects to, I am out on a limb here but I think that is correct.

[Mike Self]

check your fuel filter...when did you last change it? Way back when these cars were new(ish) there were lots of Tech Tips questions in the Roundel with the same problem, and many times it was a clogged fuel filter that simply wasn't letting enough gas flow to the injector pump. The tii filter is a much finer mesh than the filters used on carbed cars as the injector nozzles are much smaller and therefore clog more easily. So if you don't know when last the filter was changed, do so and see if that helps.

cheers

mike