Hesitation/turning Off

[govich]

Hey guys,

Recently the Skyline has been playing up a bit. The story goes - filled up BP Ultimate at the servo i don't usually fill go to. That afternoon, driving home the engine starts popping, farting and in general being very grumpy, and eventually dies. Try to turn it back on and it fires but only gets up to about 500rpm and dies again. Waited a bit, about 30 minutes, it started perfectly and i drove it home 10km without a hiccup.

Now a few days later i'm trying to get it to repeat the problem, drive 20km to a mate's place without a single bit of hesitation anywhere. Pick up mate, showboat through 1st and 2nd, keep driving up the road and it starts struggling and popping all over the place, eventually dies again. Managed to fire it up 10min later and took my mate home.

From here, things got interesting (this was last night). After waiting 30min i was able to drive for about 5 minutes before it spat the dummy and turned off. From there it was a game of waiting, babying along with hazards on and basically trying to get it home. It took about 3 hours to get it from eastwood to baulkham hills, including probably about 20 attempts to start it (glad i spent up on the battery....).

Today i checked the fuel pump, everything seems fine. It drove OK when i went up to a highway to give it a fang, but then on easy driving on the way back it crapped itself. It seems like it will only do it after the car is 'warm', or after about 20-30min of driving. That is if it hasn't been turned on for an extended period. If it's already warm (just been driven) it's prone to doing it at any time. I drained the fuel too and it doesn't seem like a bad batch from looking at it.

Cliff notes: fuel pump fine, fuel filter fine, car hesitates and turns off constantly when warm.

Any ideas are appreciated guys!

Edited April 9, 2007 by govich

[fford1386]

I'm not sure but sounds electrical most random/intermitting problems are. But I've had similar symptoms and speedworks picked up it was my AFM. I've replaced it but its doing it again - (maybe a break somewhere along the circuit or lose pins). Could it be igniter? Best bet is to have it on a dyno to try and simulate problem with fuel pressure gauge, scope on your ignition, or a scanner to read engine faults.

Good luck mines giving me a headache although I've resoldered the pins on my old AFM and it seems to be fine (so far....)

[sapsR33]

Hey guys i had the exact problem with mine

i had no injector signal, sourced it out to be a faulty cam angle sensor, this could be your problem, get the mechanics to do a test on all signal faults and hopefully you should find the problem

[Jdfnq]

how old is your fuel filter???

Could be a piece of shit in the tank that is every now and again stopping flow.....

[govich]

how old is your fuel filter???

Could be a piece of shit in the tank that is every now and again stopping flow.....

Got most of the fuel out of the tank and it looks fine. Fuel filter is about 5000km max old (changed it myself) and is fine. I can blow through it.

Currently thinking the fuel pump's had it after 13 years of service, my recent upgrade to >200rwkW and thrashing at eastern creek drags. Bosch 040 is going in very soon.

Thanks for all the suggestions guys.

[govich]

Installed a new Walbro pump tonight, which didn't fix the problem. Tomorrow i'm going to try a new batch of fuel and if that fails, i guess i have to start looking electrical.

Suggestions welcome

[Cubes]

Look at the CAS & AFM. Not really much else to them.

[govich]

Cheers Cubes. Just found this:

Engine cuts-out with tachometer dropping to zero. Attempting to restart the car immediately is futile, with no spark. After a wait of 5 seconds to 20 minutes the car can be restarted. However, once the failure has occurred it will repeat unpredictably & increasingly repeatedly.

on this site.

Couldn't have described it better myself. I guess it would apply to Skylines too. Looks like i have to hunt down a second hand CAS.

An alternative failure can be the Crank Angle Sensor,

Edited April 11, 2007 by govich

[Cubes]

Borrow a mates if possible.

Nothing worse than wasting money on items that don't fix the problem.

[govich]

Are these difficult to remove? Where abouts are they on RBs? Honestly i've never even looked at one (knowingly).

edit: LOL, never mind. Found it after looking really hard

Edited April 11, 2007 by govich

[govich]

Just for closure, the problem ended up being a stuffed AFM. One new AFM later and it's purring again.

Thanks Cubes and everyone that helped, and the guys at UAS for helping out.

Edited April 12, 2007 by govich

[mad082]

do you know what was wrong with the AFM. my mate had troubles with his AFM. i just opened it up and resoldered the 3 prongs and it worked like a charm.

[DaveO74]

Just for closure, the problem ended up being a stuffed AFM. One new AFM later and it's purring again.

Govich I was just wondering, did your "engine overheat light" come on during these hicups trying to limp home? The reason I ask is mine did exactly the same as yours today after not being started for about 6-months (Doing a couple of Mods) but made a "POP" noise before the hesitation started. I was only about 10mins from home but it feel hot when I felt the engine around 45mins after I got home. But it will still start but wont idle.

Reckon I could have the same prob????

[govich]

Govich I was just wondering, did your "engine overheat light" come on during these hicups trying to limp home? The reason I ask is mine did exactly the same as yours today after not being started for about 6-months (Doing a couple of Mods) but made a "POP" noise before the hesitation started. I was only about 10mins from home but it feel hot when I felt the engine around 45mins after I got home. But it will still start but wont idle.

Reckon I could have the same prob????

Nope, no warning lights for me. Doesn't really sound like the same problem unfortunately.

mad082, not entirely sure what the problem was with the actual AFM, just know that the car works fine after it was replaced. Might open it later but i cant see myself being bothered..