Need help in Cape Town- AFS

[Steve Irwin]

Hi

I have a 1986 Starion 2L with 90000 km on the clock. I wrote to the UK club website and only got a reply from Oscar-the-Grouch in the USA, he suggested I contact you guys as my car is most probably the same as yours (only a handfull were specially imported to SA). As the poms don't seem to want to talk to us guys in the colonies, maybe you guys may have some ideas.

My car intermittently starts misfiring/dying. The boost gauge jumps to max reading and the engine starts misfiring. Then it will clear and run trouble free for hours then start again. :?

As I understand it, the boost gauge is electrical and is driven by integrating the pulses from the igniter and the Air Flow Sensor. I
suspect it is either the AFS, the Igniter or the ECU.

I strongly suspect the AFS, as after I do anything around that area it appears to change the severity of the problem.

Also I get no reading on pin 16 of the ECU (zero volts-no constant 12V or
pulsing)

Igniter E2T151171 (MDO66844)
ECU E2T30471 (MDO41933)

Any help or info will be appreciated :D

Regards

[SpidersWeb]

If you factory boost gauge is moving to max, then your ECU is probably also seeing that same figure and activating the boost cut.

The signal to both is provided by the MAP sensor, its the golden box mounted to the firewall on the turbo side of the engine bay. Try disconnecting it, if the car starts and seems fine, then thats the problem. You'll need to repair it because having no MAP sensor can cause other problems.

The AFM/Ignitor signal method of boost measurement was only used on some of the American Starions I beleive (??).

Ours (the 2 litre) have proper MAP sensors, which are unfortunately prone to failure, and I imagine you have the same thing.

[toysrus]

Just to clarify for the others when they answer, when you are driving normally around and then go into 'Boost' the car then at some point starts to misfire right ?

If so, firstly install a Boost gauge to make sure that Boost isn't more then 7/9psi in any gear otherwise that means you have a leak in the Vacuum line from the Wastegate actuator to the or/and the wastegate rod/arm has been extended by twisting the bolt on the thread end of it generally.

[Junkers]

Sounds like a electrical problem to me, I would be inclined to follow spidersweb's advice first :)



Welcome to the forum!

[honest_jim]

That UK owners club forum is rubbish you were lucky to even get a reply on there! :x

This place is loads better :)

[Steve Irwin]

Hi

There is life out there after all!!! Many thanks to all who repied.

Special thanks to Spidersweb's- spot on- it ran fine without the MAP sensor.

Not to complicate my first e-mail, I should now tell you I bought the car with the turbo removed by the previous owner( wastegate chamber cracked in many places, bearings shot and vanes rubbing against housing).

I run a Porsche 928 on track days in Cape Town, my son is about to get his drivers licence and it suits me fine to let him run un-turbo'd for a year and then upgrade it so he can then also run on the track (when he can handle it), maybe I will then sell the Porsche and have fun with the Starion instead.

What else does the MAP sensor do? Can I continue to run without it if i am not running a turbo?

I was told by the PO that he fitted high compression pistons when he removed the turbo, but I doubt it by the slack performance, what PSI should I be getting at cranking on then normal (low) compession pistons?

If I need a MAP sensor prior to going back to turbo who should I contact, what do they cost?

It's a great feeling to know I am not alone :D


Many Thanks and Regards

Steve Irwin

[flav]

Hey Steve, if you need anything at all you can contact me.

Email me for any information or parts.

Cheers
Flav.

[TD05]

also check all the vacc hoses leading to and from the map sensor to the TBI I had similar issued and found one of them collapsed, others leaked so it pays to check those...

[flav]

YES