He does need an oil pressure sending unit, his is all over the place. I might try that, talk to you tomorrow. Thanks

Jason

 

I am a mechanic, I have adjusted more valves than I can count. that's why I am so sure they are set right. that wasn't ment to be a smartass comment, and I do apologize if it came off that way. I have adjusted them cold then hot, and the amount of preload that I had was the same.

 

Coil , coil wire, main grounds and terminals, fuel pressure under load, fuel filter ..... Just to name a few possibilities. If you could get a scanner on it to log a run that would help you alot.

 

I have a scanner at work, it's a snap on MT2500, what type of things would I be looking for. I am familiar with the scanner but as far as what certian numbers should be, I am not.

Jason

 

Mostly to check for proper O2 function .

 

Check all your electrical connections AGAIN. You more then likely are going to find something either not plugged in or whatnot. check the MAP. check for vacuum leaks. I though I was having some issues myself after my build, it ran like donkey-poop. I got the tune and all my hopes and dreams came true.

 

Hey Jason: just wondering if you found out anything yet on this thing? Also was wondering if you were going to the track this weekend? If it does not rain. Also did you find out about thoes springs? I have the car jacked up right now getting ready to take out thoes shims. and change the rear end lube. Then an oil change. Give me a call. Mike..............

 

Your car is a 94; do you still have the original lifters? I have a 94 Z and am about to start a cam and heads swap. I called Comb. Motorsports a few days ago to order rockers, timing chain, gaskets, etc. and he asked how many miles I had. 110K. He said I had better get new lifters with that many miles. Apparently this is something a lot of guys overlook. They are hydraulic and if yours are original they could be really squishy with a large cam at higher rpm's, and could be responsible for the problem. A new set of comp R's is $200. Good luck.

 

I think I might have figured it out tonight. I put the scanner on it and we drove the car around and nothing looked out of the ordinary. I don't know what the numbers should be for a perfect setup, but they look to be within the normal range I am used to seeing. The knock sensor didn't pull any timing out untill the car started running really bad.

He checked and the timing marks are lined up, which i thought they were, checked fuel pressure, it's ok, checked the wires, its fine, swapped on another opti and coil/module, no difference. Today was the only the second time i had actually rode in the car, while looking at the computer and listening to the car it felt like the valves were floating.

we put 986 springs on it, but with 1.6 rockers, not the 1.5's like comp recomends. it's .510 lift with the 1.5 and .544 or so with the 1.'6s. I have done some searching on the boards and found that the 986's arent really that good of spring. Anyone have any comments?

Thanks.

 

Not to thread jack but exactly how can a non vented opti be installed wrong? Whats the proper way to install it. I'm gonna be putting mine back on it a couple days. Thanks.

 

I would HIGHLY doubt that springs are the cause of this. The valves wouldn't float that bad at a paltry 3000 rpm even if they were damn near dead (ask me how I know ). Here's something noone has brought up yet..

If your good at low rpm's, and you don't have a skip, you can pretty much rule out mixed up plug wires and ignition problems. You've replaced the Opti (the usual suspect) as well as the ignition module and coil, so I would rule out ignition fo rthe upper RPM's too. Ok, thats Spark.

You've checked the physical cam timing, and you have it installed correctly and straight-up? You've already established that the valves are adjusted correctly (they would have to be waayy tight to do this anyway). I assume that your other two major sensors are good (MAF, MAP, and O2's). Ok, thats AIR.

Only thing left is fuel...

As to the real culprit:
Lemme guess, the car starts missing like crazy and shudders like the freakin bumpers are gonna fall off right? Well, if you don't have a AFPR yet, go get one and bump the FP up to about 55 lb's (or replace the pump itself). It sounds to me like your pump is running out of breath when a decent demand is placed on it. The weenie stocker cam won't show this problem up, but a cc305 with 1.6 rockers just might. Also, go check the (aka replace) the fuel filter. I know these are little things, but they make a huge difference. Might wanna check the voltage going to the pump as well. Could be dropping for some reason and dropping flow.

BTW, I went through the same exact thing with my buildup. The FP and pressure drop didn't show up until I put a real motor in it, and then it showed up REAL FAST. I still havn't gotten around to installing a new FP, but I have to have my FP up around 65 lb's to compensate. Needless to say, the old pump is on it's last legs and will be replaced VERY soon.

Hope this helps you out....

Dave C.
(former E'Ville resident until just recently )

 

DOH. I didn't even notice. 1 Nasty Bird DID bring this up! Sorry bout that Bird. He didn't mention bumping up the FP though. I bet it solves (more like masks) the problem..

Dave C.

 

Sounds to me like you answered your own question.

Jason

 

talked to comp cams today, actually mike did, the guy at comp cams said the 986 springs were rated to .600 lift @ 1.80 installed height, with the 1.6 rockers the lift is .544 or so, the tech guy said the spring pocket shims are .060 which is gonna put the lift on the border line or the max lift. The fuel pressure has been checked, it's 45psi at WOT, the volume however has not been checked. It doesn't feel like it's running out of fuel, it feels like the valves are floating. I am going to check the installed height later this week. The only things left are fuel volume or some freak problem I haven't thought about. Mike ordered a tune for it and should be here tomorrow. It's probably some freaking stupid that I'm over looking. I hope it's the springs.

Jason

 

Not to sound harsh, but valve float and coil bind are two different problems. Coil bind is what you get when you have springs that are too small for a given lift. Valve float is what you get when the springs can no longer control the valves at high RPM, leaving the valve open when it should normally be shut (as in bouncing on the seat typically - not really gonna nose over with this much lift). Coil bind however is going to break parts in short order. Also, you need not trust what the spring shims are "supposed" to be. Take them off and mic them. That is the ONLY way to know whats in your motor. If you end up with very tight clearences (<.050), then why not throw the 1.5 stock rockers on there for the time being and try running it then. Quick and simple way to rule out the problem.

I still think it's going to be fuel delivery, but thats just my opinion. I could even end up being the injectors themselves (they've got a lot-o-miles on em if they are stockers). If Mike doesn't have another set of stock injectors to try, then I'm sure there someone on the TSFBA site that could prolly loan him a set for testing. www.tsfba.com - tri-state area club. Some good folks on there..

Hope this helps. Say hey to Mike for me.

Dave C.