Fix your hesitation

[bignate]

thats awesome, i learned something today. But if i did replace mine id go for splitfires anyways

[Sky_Davision]

q45

Q45 V8 coils are the same, they're around $100 a piece locally, or you can try ebay.

Can anyone second this?

[rockcrete]

Seeing as I have bought and installed one, I can confirm it........ there are two different coils on the Q45's the front one on each bank and the other six, you want the kind there are six of, not the kind there is only two of.

[scred_gts4]

Hi, I'm new here and glad to meet you.

I also have a dead cylinder on my RB20. I know which one it is (the third one)

So I changed the coil and the plug under this one because it was drowned. The problem was still there. Then I checked all my coils with a multimeter and they were all on 0.9 when the engine was warm.

I also tried another Igniter, did nothing.
My girl friend father's is a mechanic and listened to the injectors, he told me that they all have the same sound, so I guess its good!

THe compression is 130, you think its too low?

Well, give me a clue I'm kinda out of ressources

[hks_gtr]

Refering to fuel pump testing, I can test fuel pump dwell time w/ a scan tool, find a repair facility w/ a MODIS snap-on scan tool, and that tool can test fuel pump dwell times and can determin if your pump is good, going, or bad.

[hks_gtr]

Hi, I'm new here and glad to meet you.

I also have a dead cylinder on my RB20. I know which one it is (the third one)

So I changed the coil and the plug under this one because it was drowned. The problem was still there. Then I checked all my coils with a multimeter and they were all on 0.9 when the engine was warm.

I also tried another Igniter, did nothing.
My girl friend father's is a mechanic and listened to the injectors, he told me that they all have the same sound, so I guess its good!

THe compression is 130, you think its too low?

Well, give me a clue I'm kinda out of ressources

Check wiring from coil too igniter, take the #3 coil swap it w/ any other cyl. if #3 miss fire, and coil you swapped with, that cyl fires, re-wire too igniter

[superdaveosbourne]

Could also be a dead injector, same symptoms on my GTR, thoguht it was a coil, turned out to be a sticky injector which has been replaced now.

[Chris_RB]

I would also recommend cleaning your AAC valve. I had a hunting idle...among other things and a clean AAC does wonders.

Here is what I used as a little help

http://www.skylinesaustralia.com/forums/Diy-Aac-Valve-Cleaning-and-t110431.html&hl=auxiliary+air+control

From my research it is one of the most common problems of a hunting idle. After doing this, just reset your idle to 900-1000RPM. I set mine on the higher side just because I think it is a bit smoother...Its all in that link

I also replaced my fuel filter...it was quite bunged up. Car has had a relatively smooth idle, and has not stalled once since these changes.

[RB25DET]

Could also be a dead injector, same symptoms on my GTR, thoguht it was a coil, turned out to be a sticky injector which has been replaced now.

I changed Coils to Splitfire and was an amazing difference and helped my original problem of hesitation. Car ran great for a while with no problems other than a rear hub that was making weird noises like rolling on marbles or something and bought one from the Skyline shop (very helpful). I ended up changing both rear hub seals (Skyline Specific unlike 300zx tt brakes that can be used on the car). I also got a truss dump pipe and downpipe to free up some back presssure the car had and worked brilliantly. Now I decided to get retarted and buy a front mount intercooler and I'm back witht he hesitation. I cleaned the MAF today and worked pretty good in low range. I still have some hesitation at like .4 bar but breaks loose and takes off once it gets past the stubborn point. I don't want to just go changing parts and stuff

[kelaog]

You might be leaning out now with the extra power ur making :P... still running the stock fuel pump? I found after I went and upgraded dump pipes and intercooler it didn't have enough fuel, once I put in a walbro pump it solved my issue.. just don't go running below 1/4 tank on those shitty pumps =/ Get an OE GTR pump if you can find one.

[ecokeRB20]

my car ran fine until a little while ago my battery died, and the car sat for about 3 days.
do you think this has anything with the ecu resetting itself?
completley stock rb20

[kelaog]

my car ran fine until a little while ago my battery died, and the car sat for about 3 days.
do you think this has anything with the ecu resetting itself?
completley stock rb20

Probably, that or it might have shorted out something like a coil etc...

Try unplugging it and resetting the ecu again by hitting the break so it learns. Just drive around normal and it should fix it. The idle will bea bit rought hwne you first reset the ecu. you'll hear some pings etc.

[j-rod144]

I've got that stupid hesitation at 5000 RPM too, and I've been talkin to some mechanics about possible problems. What do you guys think about possibly a sticky wastegate, this was the only suggestion they gave me that wasn't on your list. They said just take off your dump pipe, start it up and rev it a little and see if there is excess carbon buildup spewing out it could be holding up your wastegate when it tries to open up at max boost when you hit that 5000 RPM. Let me know what you think of this theory.

[SVTong]

I'm worried that my wastegate may be pooched as well. My car stutters like crazy past 4500-5000, then (if I'm in 1st or 2nd) will suddenly hit with full boost past 6000. In 3rd the stuttering never stops. I don't think it's the fuel pump because when the car stutters, it backfires like crazy which makes me think that there's plenty of fuel going in. I've swapped all of my plugs and reset my ECU, and I'm going to try a new ignitor soon, but it seems more like an air delivery problem to me.

[j-rod144]

Well yours sounds worse than mine, my car just shutters and major power loss in any gear past 4500 RPM if I'm accelerating hard. If I just go easy on the gas past 4500 it'll go fine. Have you thought of maybe your TPS (throttle position Sensor) ? I'm going to do that aswell as clean out my AAC valve. But for the wastegate just take off your dump pipe, start it up and see if theres alot of carbon spewin out. PS make sure you have lots of penetrating fluid, the bolts are damn near welded on.