tc101

Hi all,

I have been recently trying to get a 1988 3.2 Carrera running again after sitting for around 10 years.

Here's everything I've done so far:

1. Pulled and cleaned fuel tank. Reinstalled.
2. Installed fresh battery.
3. Replaced fuel pump (as it wouldn't run when jumping 30 & 87b on DME relay plug).
4. Ran fuel pump and diluted out old fuel in fuel lines.
5. Replaced fuel filter.
6. Replaced spark plugs.
7. Replaced oil and oil filter.
8. Removed DME relay and cranked engine. Cranked fine.

Now's where we have issues...

9. Plugged in DME relay and tried to fire up engine. Still only cranked.
10. Replaced DME relay (hoping for an easy fix). No luck. DME relay clicks once when turn on ignition and again when crank engine.
11. Tested spark plug while cranking and sparked fine.
12. Was unsure if the fuel pump was running when cranking so thought perhaps flywheel sensor is not triggering it to run. Tried jumping 30, 87 & 87b on DME relay plug to get fuel pump running then cranked engine. No luck.

Any ideas where to go from here? My next thought would be clogged injectors.

Any help would be greatly appreciated.

Thanks heaps in advance

500

Clogged injectors are a definite possibility. First though, I would try and verify that you are:

a) Getting power to the injectors (~12V with ignition key on)
b) That the injector is receiving a pulsed voltage when the starter is being operated (use a digital multimeter ideally... Alternatively, you could try - with a helper - the old screwdriver on the side of the injector trick while the starter is being operated, but not sure how easy that is to discern)

If it appears that the injectors are not getting power and signal, check the injector harness connector at the back (front?) of the engine. It is the one circled here and should be located at the top of the shock absorber support cross member:



All that said, I do think clogged injectors are a strong possibility too. Probably the best thing is to take them to a professional for cleaning. Another option is to do it yourself with a home-made apparatus where pressurized air is used to push carb cleaner through the injector while the injector is pulsed. I used a basic $30 pulsing unit I picked up off of Amazon and some hose and fittings to make this unit to clean injectors for a Subaru WRX:

Important to note though that I borrowed the TGV housing and fuel rail from the car temporarily to use as part of the apparatus.

emac911

My 3.2 sat for a very long time. I did most of the things you did. I took the injectors to a shop and had them cleaned and checked. He said they were pretty gunked up. She fired right up.

Not hard to pull them out, and blow out the rails and lines at the motor.

You may want to check the crank reference sensors, all the insulation had dry rotted on mine. I replaced them as well

oldskewel

Some other easier ideas before doing surgery ...

(I assume you are getting NOTHING regarding combustion, right?)

Put your hand on the fuel pump when it is supposed to be running, to confirm you feel some vibration. If you do, it is fair to assume that the injectors are seeing upstream pressure. However, and unlikely, something else in the path may be a problem.

Remove a spark plug and see if there is any smell of gas after cranking. If you do, that suggests some gas is getting through, although maybe not enough to fire. If no gas smell, likely to have a fuel problem such as clogged injectors.

You should be able to rent a "noid light" kit from PepBoys (etc.) - that clips onto the injector control wire and flashes an LED each time you get a pulse command. Very simple, non-invasive, can check on one of your other cars if needed.

If you do proceed to injector cleaning, I'll say that it is not rocket science, and that you may be able to do some good using brake cleaner, carb cleaner, compressed air, 9V battery and alligator clips, or just one of those and some youtube. If you see any change following that, you can decide on whether to do the rest of them, send them all in for professional cleaning, or keep searching for a different problem.

If you do decide the injectors need cleaning, ... just an idea ... I've seen some reports on here about an injector upgrade that is reported to be an improvement. So consider upgrade rather than cleaning.

tc101

Thanks so much for all the advice. You've all been a huge help.

I tested power to the injectors and all are getting around 12V. I also tried the screwdriver trick and I think it's vibrating - although it is difficult to ascertain if that is due to the cranking of the injectors pulsing. Hooking up a NOID light test kit is an awesome idea but unfortunately didn't see this reply until I had already removed the fuel rail.

I was able to remove three of the injectors fairly easily (relatively) but the other three are very tight. I am giving WD-40 some time to work on them.

So my new plan of attack is:
1. Have a go at cleaning the three injectors.
2. Reinstalling the three injectors.
3. Seeing if there is any improvement:My only concern is whether it's worth buying the pulsing kit + cleaning stuff if I am probably going to need to get them professionally cleaned anyway. I guess it's weighing up the probability of clogged injectors being the issue (i.e. if it's an 80% chance of being the issue I might as well just go straight to professional). Also I'm in Australia and there doesn't seem to be anyone renting NOID light test kits so I would need to buy one if I go down that path (although they don't seem too expensive).

tc101

Thanks heaps for that point.




From memory reading somewhere else, these are the sensor plugs right. Same here, insulation seems to be dry rotten. Could this be the cause of it not firing up? I assumed that since the fuel pump is running fine then the DME is getting enough information from the sensors to also trigger the injectors.

Is there a way that dodgy crank reference sensors could be stopping the fuel injectors from pulsing but not the fuel pump?

Vane

The insulation can be bad in engine bay as there is hot. Here is one way to verify these sensors:

https://www.ecudoctors.com/pages/por...ce-sensor-test
Check the net, lots of info about this.

If you plan to replace them, be careful not to disturb the air gap between sensors and flywheel.
When you are there, check also the cyl head temp sensor, here:

http://forums.pelicanparts.com/porsc...nsor-test.html

Highly recommend that you purchase the Bentley manual.

If you end up buying the crankshaft sensors, shop around. Same sensors are used in many cars, I ended
up to buy BMW sensors as they was cheaper. The crankshaft sensors can be changed with engine in place,
most difficult is to get the rubber grommet in place.

Remember to check the fuel hoses in engine bay, try to rotate the rubber hose in steel pipe, if turn > replace
or repair. Your car might catch fire.

My 3.2 did not start when one of the sensors was bad. Recently I had to had the injector to be cleaned and 2 was
corroded bad. The fuel with ethanol absorb moisture and this corrode the fuel injectors if the car is not regularly used.

Porsche 911.606.215.01 (Bosch 0 261 210 005) can be replaced with BMW 12 14 1 708 619 (Bosch 0 261 210 002)

emac911

I cant speak to how the insulation being gone would affect their performance as I replaced them prior to trying to start the motor. Mark them, take lots of pitcures, to make sure you dont mix them up. As @Vane mentioned they are a bit tricky to get in place. You may have found your problem.

I got mine from FCP.