engine and drivetrain Lacking Power In Tii

[billjecks]

since I bought this car 3 years ago I have always though it had some power issue. It does not seem to have the grunt my last one had. I have cleaned the tank , cleaned or replaced all fuel filters, replaced fuel pump, 

run fuel system cleaner through, changed plugs, new plug leads,new ireland distributer, adjusted timing bang on, put on new linkages, rebuilt head, ( leaking head gasket), and have seen a marginal improvement. It starts and runs great but just does not have that torque in the midrange my last one had. Short of rebuilding injectors and or injection pump, anyone have a suggestion? Who is the guy to do the injectors and or pump?

 

Bill

vancouver BC

73 tii

[FB73tii]

Do a dyno run to quantify the issue. Does the dyno show a flat spot? Is this car identical to the last one? A lot of things can make a difference--cam, piston CR, exhaust system, diff ratio, tire circumference, overall weight, elevation (did you move up to or down from the mountains?)

 

Sorry this is not a prescription for more midrange power, but it will take more sleuthing to figure out what, if anything is the issue. Getting the injector spray pattern checked is not a bad idea. Adding a wideband O2 sensor will give you info, as well.

 

Fred '74tii & '69

Edited August 11, 2013 by FB73tii

[jgerock]

Do a dyno run to quantify the issue. Does the dyno show a flat spot? Is this car identical to the last one? A lot of things can make a difference--cam, piston CR, exhaust system, diff ratio, tire circumference, overall weight, elevation (did you move up to or down from the mountains?)

 

Sorry this is not a prescription for more midrange power, but it will take more sleuthing to figure out what, if anything is the issue. Getting the injector spray pattern checked is not a bad idea. Adding a wideband O2 sensor will give you info, as well.

 

Fred '74tii & '69

+1 on Fred's advice.   WIthout a wideband 02 sensor, you will be doing lots of guesswork.   You can take the injectors partially apart and clean them either by soaking them in a cleaning solution or using an ultrasonic cleaning device.  There are other ignition timing procedures which may help tune your car.

 

Was your last tii the same year as this 73?  Did someone swap out the ring and pinion for more torque (on the other tii)?   I have driven several tii's  - even one with a CR 5-speed.  They all seem to have different personalities.

[pilotnbr1]

Leak down or compression check would be a good place to start if you heven't already.....

[ray_]

I didn't see where you mentioned valve adjustment :-)

 

Not sure where this went on the new site, but a good read and list of pump/injector rebuilders:

 

http://web.archive.org/web/20120113082041/http://www.bmw2002faq.com/content/view/66/32/

 

GL,

[PaulTWinterton]

Hi Bill, 

 

I've probably told you most of this, and I'm not a pro, but maybe you'll find some value in the details.

 

Static testing of injectors can be performed by Fred Holmes in Richmond BC.  Burst (that's my word) testing can ONLY be done by a pump rebuilder on their bench. Wes Ingram in NW Washington does that while setting up a rebuilt pump.

 

FWIW, I had Holmes rebuild mine, $25-$40ea, and did a static test. They were all indentical and had the correct spray pattern, with no leaking.

 

I must say that when I started your car I was AMAZED at how well it started.  Forget about 6 cranks.  Yours started at the turn of the key, reved up to 1500rpm, and dropped to a comfortable idle quickly.  That tells me that your fuel flow, timing, coldstart, and KF pump (at idle) are all working as they should.

 

What's left?  Valve adjustment (again even though they were adjusted during head rebuild), KF pump adjustment, compression test.

 

Without an 02 sensor, you can only check your mileage to see how much fuel you're using. That will give you some indication of how well your system is set up. 

 

Wes Ingram can do the KF 02 analysis on his Sun machine.  He spent 2 hours with me and charged me $120.  Well worth it.

 

Cheers,

 

Paul

[ray_]

You might also revisit the linkage adjustment. The tiiregister.com site has the FI manual and video on case you've not looked.

 

Cheers,

[billjecks]

Paul,

     I would think that you would have bigger fish to fry( recent body altercation) than responding to my whining about lack of power. But i do appreciate your input and maybe a drive down to ingrams shop on a sunny day may be what I need to shut me up. If he thinks your car is running well and ours are now very similar in performance, maybe I am chasing ghosts. What I do know is my valves are adjusted correctly, as is my linkage and when I had the head off 300 kms ago the pistons where very clean and the cylinder walls looked like new. As you know my timing is bang on and the beast starts like new and idles smooth. I really think if there are any issues remaining it is either injectors or the pump. Just what does ingrams do in his process to check the pump and injectors?

 

Bill

Edited August 11, 2013 by stuck on bmw