Mystery Problem With Injectors+spark

[RB20_ZED]

A few days ago i took off from a set of lights pretty hard, spun the wheels a bit and all of a sudden the car spluttered, hesitated and nearly stalled when i took it out of gear.... but i got it home and took it to the mechanic who did some tests and said its running super rich and missing etc.

He looked around and eventually called me and said it was the cold air idle valve (he unplugged it and suddenly the car ran perfect)... which made sense coz its been running badly when cold for a long time.

When i came to have a look, he tried to start the car and it wouldnt start at all... so he kept it and said that there was no spark and no power to the injectors...

So we get the ignitor and CAS checked and they are both working fine... and after putting them both back on he now said that there is "a little bit of power" going to the spark plugs and said he is going to pull them out and have a look...

im starting to get the shits with the way things are going and wanna know if anyone has any ideas or suggestions as to what the prob may be???

(Its an RB20det)

[RB20_ZED]

update:

The reason there was no spark was bcoz the spark plugs were fouled... cleaned them and the car now stumbles and hesitates like before...

WHat could be causing it to run SO rich???

[sky-017]

could be spark plug gap . that can cause misfire = also check your coil packs arent cracked . you loose spark through cracks

[WazR32GTSt]

AFM not plugged in properly, or just simply shagged?

[RB20_ZED]

Thanks for your help guys.

could be spark plug gap . that can cause misfire = also check your coil packs arent cracked . you loose spark through cracks

Nah mate - its running super rich which fouled the spark plugs... cleaned them and its definately getting spark (and power to the injectors) - i think the mechanic was stupid/didnt know what he was checking.

AFM not plugged in properly, or just simply shagged?

Yeh i thought that but ive checked it and cleaned it with electronic cleaner and still the same - and all the little wires seem intact with the afm... guess it could be screwed- how could i diagnoise a faulty AFM besides swapping it?

Could a faulty O2 sensor cause this kind of rediculous over-fueling? ive been reading a ton of posts and hearing a lot about ecu's in limp mode but cant seem to find an explanation of what that means...???

its so rich that its un-driveable... idles irratically at around 400 or so and the engine stalls very easily... revvs like a pig and blows plenty of smoke... way too rich. Any more suggestions would be very much appreciated.

[WazR32GTSt]

can you get your hands on a cumputer with nissan datascan? that can do a diagnostics check and look at a variety of sensors to check things out...

[WazR32GTSt]

or what about an intercooler pipe that has worked loose somewhere? check behind the front bumper etc. could account for the over-fueling but not really for he "no power to injectors etc" argument.. worth a look anyway

[cheez]

sounds like the same issue that i had some time ago.

check your afm properly, it may look like the contacts are ok but skyline standard afm's have a case or getting dry solder cracks.

check out this post for the simple fix, its just a matter of adding more solder, if it dun work well at least you know ur afm wont falter any more under heat with new solder in play.

hope it helps

http://www.skylinesaustralia.com/forums/in...p;hl=afm+repair

daniel

[RB20_ZED]

thanks heaps for your help guys.

WazR32GTSt:

I checked the intercooler piping and took the joints apart and connected them all real tight and no change.

The injectors do work - the mechanic was just dumb - the sparkies just get fouled real quick. Had to clean the black off the spark plugs again today so that it would at least start.

cheez:

I can get it to rev over 3000rpm so does that rule out the afm issue? it doesnt rev nicely... but i can still get it over 3000 (smokes out the neighbourhood tho!)

Im starting to think its the ECU...

[cheez]

doesnt rule it out actually rules it IN!

if the afm doesnt get a clear signal, it send the car into wats called limp mode where it doesnt allow the car to rev above 2500-3000rpm. try the dry cracking solder repair and it should fix ur prob by the sounds of it.

the smoking issue is also part ot the problem, the afm doesnt have any idea of air going into the engine so either over compensates or runs lean. try it. only takes about 30mins to do.

hope it helps

Edited March 14, 2007 by cheez

[WazR32GTSt]

maybe just try another AFM from someone else's car... takes 5 mins to change

at least then you will know if that's the root of your problem

[RB20_ZED]

Update:

Took the AFM off and did the re-solder job as well as cleaning it out with electronic cleaner again.

To be honest the solder looked fine but still thought id do it...

There was no change. Car still runs super rich and is undriveable. Maybe the AFM circuitry is fried but cant get hold of another to test this theory (its the red top AFM - different to the silvertop)...

Thanks for your help again guys... and if anyone else has any suggestions (or knows where i can buy a AFM for a red top rb20) - lemme know!

I spose theres a chance the AFM is fine and ECU mite be fried instead...?

[Devils_Advocate21]

Vacuum or air leak. Have you checked the O2 sensor?