efi flapper running probs

Seight-V8 · Post by **Seight-V8** » Sun Jul 01, 2007 10:21 am

hello all,

can anyone help me with the following problem on a 3.5 efi flapper.

Had all of the injectors recond (new filters & pintle caps), then ultrasonically cleaned.

Mean while i had my inlet maifold machined back to 90deg, as it had warped.

On engine re-assembly the engine struggles to run, when it runs its very lumpy and wont idle at all.

When it gets up to temperature and i disconnect the coolant sensor, the engine will smooth out and run pefectly, although its not correct.

Tested all the efi system yesterday from info on here, and it all checks out.

Even the coolant sender checks out to the info, and i even put it in some boiling water to check.

So what does removing the coolant sender do, rich or lean the mixture.

I'm off the land rover tomorrow to get a new one.

Any help appreciated

scott richmond

Post by **katanaman** » Sun Jul 01, 2007 11:06 am

Have you checked for air leaks around the manifold and between manifold and flapper?

ramon alban · Post by **ramon alban** » Sun Jul 01, 2007 11:33 am

Seight-V8 wrote: So what does removing the coolant sender do, rich or lean the mixture.

scott richmond

Scott,
The coolant sensor operates in a range from approx 5000 ohms cold to approx 250 ohms hot.

When you remove the lead from the sensor the ECU sees infinitely high resistance (open circuit) so it will assume the engine is very cold and causes the mixture to run at its richest setting.

When the engine is cold it would seem to run ok, but because the ECU is expecting to see approx 5000 ohm, not an O C, I would be surprised if it ran at all well and would get progressively worse as it got hotter.

I expect you've seen the stuff on my website which I am adding to it all the time.

Seight-V8 · Post by **Seight-V8** » Sun Jul 01, 2007 1:25 pm

hiya all,

i have checked for all the leaks i can.

i have blocked off all the vacuum pipes, and the extra air valve pipes, when its hot and used wd40 along all the joint lines...nothing.

Doesn't make any difference to the problem i have, so dont think its an air leak.

I have fitted a composite inlet gasket this time, unless the leak is under the manifold, which i cannot check, but my manifold has just been skimmed back to 90deg.

If the new coolant sensor doesnt work tomorrow...what are my options???

Maybe only the ecu left, and that was recond a few years ago now, by lucas.

thanks again

scott richmond

Post by **katanaman** » Sun Jul 01, 2007 1:32 pm

when you checked all the sensors did you check them at the sensor itself or at the ECU plug? These looms are old now and the actual wiring can give loads of problems.

Seight-V8 · Post by **Seight-V8** » Sun Jul 01, 2007 1:42 pm

hiya,

no i havent checked the readings at the ecu yet, as its difficult to get to in my westie.

Will do that after tomorrow when i fit a new coolant sender...as i last resort type thing.

thanks

scott

Seight-V8 · Post by **Seight-V8** » Wed Jul 04, 2007 4:46 pm

hello again,

well a new coolant sensor and guess what....yep no difference what so ever....

Dont know where to look next....only the ecu left....

dont think its a air leak, as when it does run with the coolant wire off...its rock solid running at 1000rpm no surging at all..

can anyone else suggest something.

thanks

scott

ramon alban · Post by **ramon alban** » Wed Jul 04, 2007 6:18 pm

Seight-V8 wrote: Dont know where to look next....only the ecu left.... dont think its a air leak, as when it does run with the coolant wire off...its rock solid running at 1000rpm no surging at all..

can anyone else suggest something.

Because its probably not an original "Rover" installation in your Westie it is likely that there is something non-standard about your set-up, which makes our guessing pretty dodgy.

The only thing I can suggest is to go through the test program again with initial attention to wiring faults and air leaks. Then test all the components again, for faults.

If you could come back with more symptoms it might help.

Also dont forget to check the ignition system again, the ign amplifier for example has a finite life, and they always play up before failing.

ChrisJC · Post by **ChrisJC** » Thu Jul 05, 2007 6:55 am

I can't see you say that you've done all the tests at the ECU connector?

That would be my suggestion as well.

Chris.

Seight-V8 · Post by **Seight-V8** » Fri Jul 06, 2007 3:18 pm

hello all,

Well i've tested all the connections at the ecu plug and everything is correct to the wiring diagram.

Put my colourtune in each cylinder and some are running rich and some are running lean.

Could this be the flow rate of the injectors causing this....soon as you connect the temperature sender the mixture goes lean then engine stops

Maybe the injectors are just not flowing the same amount.

Anyone suggest a test that can be done on the engine...other than the resistance which is fine.

thanks again

scott

ChrisJC · Post by **ChrisJC** » Fri Jul 06, 2007 3:27 pm

Ooh, interesting.
Could be injectors. But before taking them out for independent test, I would check that the resistor pack is OK, and the plug that goes into it.

Chris.

ramon alban · Post by **ramon alban** » Fri Jul 06, 2007 4:34 pm

Seight-V8 wrote:Put my colourtune in each cylinder and some are running rich and some are running lean.Could this be the flow rate of the injectors causing this....soon as you connect the temperature sender the mixture goes lean then engine stops. scott

Lets be clear about one thing, the temp sensor has to be connected but the symptoms mentioned give some clues.

When its disconnected the ECU says let get RICH.

So clearly the engine is running much too lean and the removal of the sensor richens some of the injectors enough to get some life from the engine. Buts its not life as we know it, JIM.

Reconnecting the sensor it all goes TOO Lean again

As Chris says, the The Injector resistor pack looks like prime suspect because an open circuit situation could cause - ZERO fuel from 4 of the injectors, and normal fuel for the other 4.

Temp sensor off adds sufficient fuel for the engine to run on 4 pots. Temp sensor on and the engine cant run on 4 pots.

Check both injector and resistor pack according to the following:

http://www.vintagemodelairplane.com/pag ... tor01.html

To read all about the AFM go here:

http://www.vintagemodelairplane.com/pag ... ter01.html

but dont get too ambitious with it.

Seight-V8 · Post by **Seight-V8** » Sat Jul 07, 2007 3:56 pm

hello again,

Well removed the injectors today and set the fuel pressure at 36PSI.

Using a very crude method i ran the injectors for 1 minute and measured the results in a container.

hhhmmm and i found the following

cylinder 1 - 140ml cylinder 2 - 145ml
cylinder 3 - 122ml cylinder 4 - 155ml
cylinder 5 - 125ml cylinder 6 - 110ml
cylinder 7 - 170ml cylinder 8 - 133ml

None of them near the require 185cc/min as quoted for my injectors.

Could this my my problem, as looks like the engine would be running lean...maybe why it needs the coolant sender removing to run.

Thats a 35% difference when i think a 5% would be alot.

scott

ChrisJC · Post by **ChrisJC** » Mon Jul 09, 2007 8:03 am

Have you checked fuel pressure?, it should be between 25 & 32psi.

Chris.

Seight-V8 · Post by **Seight-V8** » Sun Jul 15, 2007 2:15 pm

hello all,

just to let everyone know i finally sorted it today and found out what the problem has been.

As from my previous post about the injectors, took them back to the place that supposed to have ultrasonically cleaned them.

Had them done again...and took 4 days.

And flowed them again....readings were 175-202cc/min.

So popped them back in and re-assembled everything.

Now it runs & revs fine, just like it should....

Only took 3 weeks to go back to where i started....the injectors...

So thanks for everyones help.

When the weather gets better, i think a trip to ray at V8D, who has been very helpful might be the best thing, to finally sort it once and for all.

scott richmond

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