geordieggg

I take it from your post that there's not that much of a difference between the stock L28 and L26 cams. Everything I read pointed to the L26 being better, but no-one could say how much better.......... Is there a particular grind I should be looking at getting, considering the minor upgrades I've done? I've asked Kelford Cams here in NZ what they'd recommend, but I know nothing about duration/lift etc........... Like I said, this car isn't a race car, but when it's driven, it's pushed hard (and I do mean hard!!) and does get to the local track occasionally, but there will be no more upgrades for this motor.

Someone else will probably go into more detail, but GRS30 is RHD 260z 2+2 and yours LHD 2 seater. When you say a "LITTLE bigger", does anyone know if it'll make much difference? Is it worth the swap, or should I just not worry about it? I don't want to buy a mild cam for this engine then have to get another one when I build the stroker, this engine is just for a bit of short-term fun, that's all.

Ok guys, have read on here a few times that an L26 cam is slightly better than an stock L28 cam, is this correct? My S31 has an N42 head, flat top pistons, extractors, everything else is bone stock, and I have a GRS30 with L26 motor which is bone stock as well. Having heard the above about the cams, I figure it's a cheap way of getting a bit more response from the car, as I drive it pretty hard, get to the track occasionally in it etc. It's not a full-on racer, more of a show-car, so looking for something to improve the motor a little more without spending the big $$$'s while I save for the race car. The other things that concern me is that the cam that's in the S31 now doesn't have the oil spray bar on the cam towers, is it just a case of swapping the towers over to use the spray bar? Is there any reason I cannot do this while the head is still on the car (aligning cam towers etc)? Thanks

Could do if the injectors are being pushed onto the o-rings on an angle and aren't sealing right, causing a vacuum leak. Check for vacuum leaks by getting a can of engine start or something, and start spraying it around one area at a time. If the idle settles down, there's your problem (if not your engine may look a little cleaner!!) That'd be second on my list, check your base idle screws, then get your hands on the EFI bible for your car and go through that one connection at a time if the idle screws do nothing. Also check your fuel pressure if you can, your timing, and your manifold vacuum, as that may give you a good indication of what's going on. If it's down low, there's a good chance either there's something majorly wrong internally, or there's a vacuum leak you haven't found so far (even with the spray trick)

It'll be a notched E88 head if it's a Skyline motor. While it's running, move the flap on the AFM, see if that makes a difference. Also check your TPS. This is assuming your fuel pressure is correct and spark is all good. Does it rev ok?

Never got that far tonight, but started checking things again. It's definitely got spark and air. Pulled the cold start valve right out, made no difference, so hooked it up running into a container and saw that it worked fine, sprayed fuel for a few seconds then stopped. When I first checked the TPS at the switch, I got an open circuit no matter where I held the throttle, so I cleaned the contacts and it made an instant difference to the readings. Could a faulty TPS connection cause this sort of problem, or should I continue looking elsewhere?

Might try this tonight in case it's got fuel in the manifold.............

Here's the story so far: Car is a GS31 that's had the original L20A removed and replaced with an L28 by PO, whoever did the swap left all the L20 EFI gear (manifolds, ECU, AFM etc) there and hooked it up to the L28. Car ran fine when I first got it, started first go. Since putting the motor back together and doing a few laps at Teretonga (a local race track), I've had the car out a couple of times, without any major problems. She seemed to run a little rich on cold starts (a bit smokey when revved but it cleared as it warmed up) and drove fine. On Saturday, drove it around town a little bit, bought it out home and parked it in the hay shed. Saturday night, had to move it out, started fine. Did what we had to do in the shed, so I started it back up, moved it inside and parked it in the middle of the shed. Sunday, had to move it from where it was, wouldn't start. Cranked a coupe of times and coughed. Did this three times, then just plain wouldn't start and hasn't since. I've checked, it's got spark, air and fuel. Nothing had changed on the car since parking it Saturday night and trying to start it Sunday morning, so it's got me stumped! Now when I try to start it, it smells like it's flooding, so I checked the coolant temp sender and the thermotime switch, both check out ok (checked the coolant one through the harness at the ECU, and was still fine). What else could it possibly be? Is it possible for the cold start valves to stick open? I know the thermotime switch should only allow the cold start valve to open for a set amount of time, should I just remove the cold start valve and see what happens when cranking?

The HQ rotary wasn't actually factory built from what I understand, it was shipped to Japan in pieces where Mazda then fitted it with the rotary http://en.wikipedia.org/wiki/Holden_Kingswood#Mazda_Roadpacer http://www.mazda.com/history/rotary/g2-6.html