86 RX EFI issues .

Gannon · Post by **Gannon** » Wed Jan 06, 2010 8:28 pm

You mentioned resistors in the relays, are you sure they arent diodes. Reverse bias diodes are used to prevent damage to integrated circuits from voltage spikes caused by the collapsing magnetic field when power is removed from the coil.

steptoe · Post by **steptoe** » Wed Jan 06, 2010 8:29 pm

all you want then is a diode protected relay. Bosch do them, as do OEX? thru Ingrams/Repco. Even your local LPG conversion workshop may likely stock them as they are used to protect ECU's in conversions and are a bit like your big bore thermostats - twice the price of a normal one. The only downside is that they have a different terminal configuration to the factory relays,

steptoe · Post by **steptoe** » Wed Jan 06, 2010 8:30 pm

SNAP!! You beat me Gannon, by a minute!

steptoe · Post by **steptoe** » Wed Jan 06, 2010 8:37 pm

The glovebox has ben the traditional useles space to tie up with new relays and computers and stuff. I am planning a water ingestion system ala autospeed using an inverter - thinking inverter will live in glovebox. Got my little Ulka vibrating espresso machine pump before Xmas. 220V 48W. Need to quiz autospeed on the finished plans, can't find good detail,

discopotato03 · Post by **discopotato03** » Thu Jan 07, 2010 6:27 am

My mechanic friend said its a resister and showed me the symbol for it on the relays shell . He did speak about resisters and diodes and how mobs like Bosch do both as well as their generic ones . He mentioned that the resistor is there to prevent surge damage .

BTW has anyone had any issues with their ECUs water temp sensor probe ?
Are they the same for 3 and 4 ECU plug cars ?

A .

steptoe · Post by **steptoe** » Thu Jan 07, 2010 8:30 am

I'd be asking FROG on last question

discopotato03 · Post by **discopotato03** » Thu Jan 07, 2010 1:38 pm

Loom aside the ECU and its water temp probe are the only things that are original EFI system wise . Injectors cleaned/cheched a while back .

Might price that probe anyway because if its telling the computer major lies it wouldn't be happy .

Cheers A .

discopotato03 · Post by **discopotato03** » Thu Jan 07, 2010 6:16 pm

The local Ripco outlet has an ECU temp probe but the listing is for 87 on .
I had a look in the 86 and 87 WSM EFI sections because they have small graphs of the resistance vs temperature scale , exactly the same graphs in both so I'm reasonably sure they are the same .
I'll ask my mechanic friend tonight and take an old sample from one of my pile of EA82 manifolds to make sure they are the same thread and length .

If it gets changed I'll ask him to change the injector style plug over to a later finger spring clip type so its easy to unplug without tools .

Cheers A .

discopotato03 · Post by **discopotato03** » Fri Jan 08, 2010 7:34 pm

Latest update is that I got my friend to change the computers water temp probe over to the Bosch one that came with the new computer .
Jeezus those spider inlet manifolds are a PITA to do anything with . The temp probe is is in the back of the water log right underneath one of the FPR's lines so awkward to get at . Plug was changed to an AMP injector one but its a real PITA to get on and off because of the lack of space around it .

I was hoping to lose the mad mode and EGR code but the mongrels still there .
I got the impression that the engine ran a little cooler from the temp gauge but have to see over time .

I'm running out of things to check , I think I have a spare flap AFM to try but not a 3 plug turbo computer .
I don't suppose anyone has a good 85 or 86 Manual RX Turbo L Series Computer up for grabs ?

Will try the AFM in the near future , cheers A .

steptoe · Post by **steptoe** » Fri Jan 08, 2010 10:25 pm

What has Checkers got left over from his EJ swap in?? A redundant ECU 3 plugger perhaps??

And why not an auto ECU? Mine has a pin to be earthed or switched between manual or auto. I did not alter mine when I went from auto to manual. But then I am on the lpg and ECU fuel side not in use (other two plugs are in), but when I did switch to petrol , things were not in the best of tune for some of the time. I was chasing what ended up being a dud coil and later the corroded fusible link

phillatdarwin · Post by **phillatdarwin** » Fri Jan 08, 2010 11:33 pm

I might have one in about 3 month's time. ecu

discopotato03 · Post by **discopotato03** » Sat Jan 09, 2010 3:49 am

I do have another coil I can try from an 85 auto Vortex EA82T .

What coil did you end up using ?

A .

Checkers · Post by **Checkers** » Sat Jan 09, 2010 7:52 am

Checkers wrote:
If you need test bits I might be able to help you out as my RX was running sweet without any fault codes or issues when I pulled it so it would be fair to guess all its sensors etc are in good nick.

steptoe wrote:What has Checkers got left over from his EJ swap in?? A redundant ECU 3 plugger perhaps??

I offered my stuff up a few posts back and got no response, so didn't bother offering again.

steptoe · Post by **steptoe** » Sat Jan 09, 2010 11:02 am

Bosch MEC 717 in use with my 3 plug ECU, sep knock box combo 86 model auto EA82T. I don't think it was my coil now after they way the corroding fusible link killed things, and after the autopsy on the coil giving no indication of anything wrong, burnt , broken

Checkers tried and responding - NOTED

discopotato03 · Post by **discopotato03** » Sat Jan 09, 2010 11:27 am

Sorry Checkers I must have missed your offer .

The bits I'd like to try are an AFM and another computer , do you have them and are you in NSW ?

Cheers , Adrian .

steptoe · Post by **steptoe** » Sat Jan 09, 2010 1:21 pm

Says he is in QLD. They have Aussie Post up there too Disco. The pics in Checkers EJ conversion shoot depict a flapper AFM .

proquip.com.au have some nice collectio of spike protected relays, from a pic they look like the same config of our subie relays hook up. DIAC SAFE brand

discopotato03 · Post by **discopotato03** » Sat Jan 09, 2010 5:43 pm

I had to go out earlier and thought what have I got to lose by disconnecting the $#@&* EGR solenoid valve . It didn't go into mad lean mode though co pilot said the ECU light came on briefly .

It seems old mate is going to break my Multimeter over my head if I don't learn to use it so had a poke around to see what voltages were like in the system . Surprisingly the battery only read ~ 13.9v and I thought it would have been in the low 14's . Alternator out put was a bit higher and the feed to the fusable link box a little less than alternator output . The positive side of the coil was down a tad on those figures .

Since the computers ignition power relay and fuel pump relays are now within reach I probed the backs of the connectors and the FPR was a little lower than the computers IGN one .
My mechanic friend always reckoned any voltage drop was a bad thing so I guess I'm going to have to try and renew some wiring and terminals .
He suspects mad mode is something to do with fuel pressure but no ones betting their life on it .
I need to ask him if its practical to make new power feeds , which the other computer needs anyway , and use the existing FP relay to switch the new relay/feed .
I also need to know what L Series Alternators are supposed to pump out as 14.2 to 14.4v would be nicer IMO . Must check out its reg .

Later , cheers A .

discopotato03 · Post by **discopotato03** » Sat Jan 09, 2010 10:15 pm

A change of alternator has the voltage up to ~ 14.1 - 14.2 so better around the fusable links/coil/FPR/ECU Ign Rly .
Mild mad mode still there and more testing to do tomorrow arvo .

A .

Dug out spare coil and will try that too .

steptoe · Post by **steptoe** » Sun Jan 10, 2010 8:37 am

I'd like you to source a fuel pressure gauge and tap into fuel pressure anywhere you see fit, tape gauge to windscreen outside, check that connections are pressure tight and safe and take your co pilot for a drive until you see or not see a relayionship between fuel pressure and MAD mode. It is one of the best diagnostic tools I have used time and time again to prove a mechanic mate also needs to keep his gauge in his back pocket and USE IT TOO! I used a gauge that read high pressure so 36psi was low on its scale but good enough to see that it dropped to ten or less when dramas occured.

discopotato03 · Post by **discopotato03** » Sun Jan 10, 2010 3:15 pm

I don't have access to one but will look into it .
I had the miltimeter probes between the FPR's power out and of all things the lighter socket for earth to see if there was a voltage drop in mad mode . I don't think there is . 13.85-13.96v .
Someone mentioned a water leak and computer probs so may pull it out and see if the cover can be removed to spot water damage . I get a small pool of water on the drivers side mat after heavy rain .

Cheers A .