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Hits wall at 4000 rpm/limited performance - ref sensors?
http://forums.tipec.net/viewtopic.php?f=25&t=23443		 Page 2 of 6
Author:  mikseymono [ Tue Jul 31, 2018 1:31 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
Update.....so all the washers and sensors arrived today.

Spaced everything up. 0.8mm washer on end of old sensor as a guide to set the bracket and 0.3mm 'S' washer under top of sensor and bracket. Plugged in new sensor and NO difference.

Really running out of options here. Someone has suggested the main DME, (as in ECU).

For me, going back to basics I was just looking through the recent bill of works and the last thing the garage I bought from had done was the timing. I checked the balance shafts and they were out by 7 teeth..circa 90 degree degrees....the TDC and line on camshaft sprocket looked OK...but having read more and more on our little beauties if it were one tooth off would this create this problem? What are the symptoms of it being say one whole tooth out?

Thanks,

M
Author:  broady_6 [ Wed Aug 01, 2018 9:56 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
If the cam is 1 tooth out then youre getting the spark at the wrong time and the rotor arm is on the end of the camshaft. i havent a cam to had but lets guess at 40 teeth on it. So get that 1 tooth out 360/40=9 degrees.

Always worth going back to basics, check the belt alignment. Have you checked the airfilter and full air in take path? Tried running wiht out it?

Have you checked for air leaks in the intake system after the AFM? Split hose, or manifold not sealing on the head?

Is that lack of reving while driving, or when the car is parked? Or both?
Author:  mikseymono [ Wed Aug 01, 2018 9:59 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
Thanks...lack of reving is all situations. Have changed air filter and checked for leaks. It is a real headscratcher....
Author:  broady_6 [ Wed Aug 01, 2018 10:02 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
mikseymono wrote:
Thanks...lack of reving is all situations. Have changed air filter and checked for leaks. It is a real headscratcher....


How did you leak check? spray a light oil at joints? id say have a close check of you cam timing. Slow to accelerate and no top on can be a result of retarded ignition, and also with the belt a tooth out you cam timing is a mess and youll not be getting air in or exhaust out when you need too. Further choking the engine
Author:  j.c [ Thu Aug 02, 2018 7:28 am ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
I think that (in basic terms) when the AFM gets wide open then the DME sees the RPM and controls the fuel required, Have you checked that you have the correct injectors? weak coil? ignition module?
Author:  mikseymono [ Thu Aug 02, 2018 7:57 am ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
I have checked the coil and it is good. Not sure what you mean about the ignition module. What and where is this?! Mine is a 924S. As for the injectors, these have not been checked. But will go back to basics and look at the timing again.

Thanks,

M
Author:  mikseymono [ Thu Aug 02, 2018 8:04 am ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
broady_6 wrote:
mikseymono wrote:
Thanks...lack of reving is all situations. Have changed air filter and checked for leaks. It is a real headscratcher....


How did you leak check? spray a light oil at joints? id say have a close check of you cam timing. Slow to accelerate and no top on can be a result of retarded ignition, and also with the belt a tooth out you cam timing is a mess and youll not be getting air in or exhaust out when you need too. Further choking the engine


Leaks checked by spraying Carb spray at all joints whilst engine running and listening for any change in engine noise. But will have a closer look at timing. Hoping for at least one tooth off..... :albino:

Cheers,

M
Author:  broady_6 [ Thu Aug 02, 2018 8:18 am ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
Keep us posted!
Author:  j.c [ Thu Aug 02, 2018 8:24 am ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
mikseymono wrote:
I have checked the coil and it is good. Not sure what you mean about the ignition module. What and where is this?! Mine is a 924S. As for the injectors, these have not been checked. But will go back to basics and look at the timing again.

Thanks,

M

It's by the righthand headlight as you look at the engine, when you say it wont rev passed 4000, doe that include when going down hill, if so then sounds like more electrical than fuel, try swapping dme if you can find on to borrow, if the timing belt has slipped a tooth, it could possibly rotate the rotor enough that when ignition timing increases, the gap between rotor and dizzy contact is too big for the spark to jump
Author:  mikseymono [ Thu Aug 02, 2018 8:34 am ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
j.c wrote:
mikseymono wrote:
I have checked the coil and it is good. Not sure what you mean about the ignition module. What and where is this?! Mine is a 924S. As for the injectors, these have not been checked. But will go back to basics and look at the timing again.

Thanks,

M

It's by the righthand headlight as you look at the engine, when you say it wont rev passed 4000, doe that include when going down hill, if so then sounds like more electrical than fuel, try swapping dme if you can find on to borrow, if the timing belt has slipped a tooth, it could possibly rotate the rotor enough that when ignition timing increases, the gap between rotor and dizzy contact is too big for the spark to jump


It can just about get to 4000 rpm....but quite slowly......includes uphill....but feels really strained. When you say swap DME do you mean the small relay in the passenger footwell next to the fuses or the ECU brain in drivers footwell (RHD) ?
Thanks,

M
Author:  broady_6 [ Thu Aug 02, 2018 10:19 am ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
DME is the ECU in this world. ive got an early 944, I assume its in the same place at the 924S which is drivers side under the dash, Itll look like this

Image
Author:  mikseymono [ Thu Aug 02, 2018 12:27 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
Yes...DME this is mine:

Attachments:
ECU.jpg
ECU.jpg [ 31.38 KiB | Viewed 5242 times ]
ECU.jpg
ECU.jpg [ 31.38 KiB | Viewed 5242 times ]
Author:  mikseymono [ Thu Aug 02, 2018 6:20 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
Have just found out the speed sensor female plug is intermittent. This is the plug that goes back to the DME (ECU) It is the wires just behind the plug....certain bending produces no tach bounce/start and another way starts straight away......probable my fault as I have pulled these apart 20 times or more in setting various sensor gap combos....

So, finally, a problem that I can solve....HOORAY.

So, what are the options please to repair this lead.....not much room or length in the lead to splice much.

Would this have an impact on my rev issue or am I being over optimistic?!

M
Author:  Prophead [ Thu Aug 02, 2018 10:00 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
mikseymono wrote:
Have just found out the speed sensor female plug is intermittent. This is the plug that goes back to the DME (ECU) It is the wires just behind the plug....certain bending produces no tach bounce/start and another way starts straight away......probable my fault as I have pulled these apart 20 times or more in setting various sensor gap combos....

So, finally, a problem that I can solve....HOORAY.

So, what are the options please to repair this lead.....not much room or length in the lead to splice much.

Would this have an impact on my rev issue or am I being over optimistic?!

M

It cant have helped, that's for sure. It could have been getting brittle before hand. Fortunately (for me) I've not had to deal with these sensors or their wiring - yet - so I cant offer much advice. Other than it might be worth giving your local OPC a call to find out the cost of that section of loom although I would suspect it would be the whole sensor loom for the DME. Failing that, they might be able to supply a replacement plug that you can splice in some new wires with.

Hope you get it sorted.
Author:  j.c [ Thu Aug 02, 2018 10:13 pm ]
Post subject:  Re: Hits wall at 4000 rpm/limited performance - ref sensors?
mikseymono wrote:
Have just found out the speed sensor female plug is intermittent. This is the plug that goes back to the DME (ECU) It is the wires just behind the plug....certain bending produces no tach bounce/start and another way starts straight away......probable my fault as I have pulled these apart 20 times or more in setting various sensor gap combos....

So, finally, a problem that I can solve....HOORAY.

So, what are the options please to repair this lead.....not much room or length in the lead to splice much.

Would this have an impact on my rev issue or am I being over optimistic?!

M

Yes, it definitely could have a bearing on your symptoms,
pull each individual wire until one or more stretch, pull on the ones that stretch until the insulation breaks, if it breaks right at the plug (most likely) the plug should be able to be dismantled unless it is molded (I'm on holiday and no Porkas in Crete that I can see) the best 2 options are, if you can dismantle the plug to each individual pin, do so, bend the tabs which crimps the bit of insulation left on the pin open, snip off the remains of wire, strip back 3mm of insulation off the wire going into the loom, place wire back in the pin, bend tabs back over wire leaving the exposed 3mm of wire resting on top of the original undisturbed crimp, solder the wire on to the connector, try to keep the amount of solder to a minimum as too much will not allow the re-assembly of the connector, re-assemble connector.
One potential problem is that the copper wire might be oxidised, if this is the case, if you have "Bakers" flux or similar, use it, if you don't you can scrap the copper wire thoroughly with a stanley blade or sandpaper.
The second way is to get a complete connector with wires attached and solder the connector (with wires) to the loom, try and used heatshrink to insulate solder joints, there is also liquid vinyl tape if space is tight
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