Bigger cams, and idle issues...........
 

I've got the aftermarket cams JWT stage 2 cams for the VQ35DE, and I had read where they would give idle issues.

Anyway, I just got my new engine started, and running. I have to feather the throttle to keep the engine running. Its pretty tricky as without finesse the engine will quickly rev over 2k rpms which isn't good for an engine that hasn't been broken in.

I did read somewhere that the cure is as simple as drilling a small hole in the throttle body blade. I can see how this should fix the issue as it was a fix on carburetors for many years.

My question is what size drill bit to use?

Of course this will be just a temporary fix so that I can get the engine broken in, and fix any other issues that can happen with a new engine, new transmission. I will most likely buy an Uprev tuner, but funds are just too short for now.

I've heard of this fixing bigger throttle bodies but nut cams, have you raised your rev limiter to 1000rpms?

Just get uprev and tune it don't ruin your Tb

No chance of doing that it won't start.

Like I said the engine did run yesterday, but I shut it off to adjust the shift lever on the auto transmission.

I did recheck the trans lever adjustment, and its dead on.

I did the IPDM check, and everything worked fine there.

I did get a code p1065 which means

ECM back up RAM system does not function properly. ECM power supply (back-up) circuit is open or shorted.
Causes:
Harness or connectors
ECM failure

So I checked all of the harnesses, especially the harnesses near the trans shift lever, and everything was good.

Did a compression test, and got 165psi, so we know that is good [I know, no spark the compression test is redundant, but what the Hell].

So I pulled the intake, and had my wife turn the ign to the on position while I looked down the intake ports for fuel from the injectors.

Well, WTF, no fuel, none.

I checked the fuel pump fuse under the dash again, and it was fine. Then I swapped the fuel pump relay on the IDPM for the headlight relay, and the headlights worked fine so that isn't the problem.

Tomorrow I will pull the fuel pump. Anything else I should check? The car has been sitting for nearly a year now, and had 190k on the clock before a total rebuild so there may be God knows what in the gas tank.

What fuel pump do you have? I can hear my walbro 255 prime and running.

My blade is drilled - approximately 1/8" hole. Nothing sexy just in the throttle blade like you said. If the throttle body had an air bypass valve/solenoid then this wouldnt be necessary.

Here is the overly complex fuel pump out of the car.

As we all know there isn't a replaceable fuel filter.

I would love to get the canister [still in the pump enclosure by the fuel level] out, and inspect it for sludge, etc, BUT I think the damned thing is made into the fuel pump unit.

I really don't want to buy a whole fuel pump assembly as I would like to just replace the pump with a higher volume unit, BUT again, I would like to get rid of that damned canister even if it means converting to a universal/ REPLACEABLE fuel filter.

http://i248.photobucket.com/albums/g...psjd2ckylg.jpg

Thanks. I knew I read about doing that mod somewhere.

probably messed up the timing during cam install.

Does sound like a tooth off to me. Why did you do this without up rev?

which exact cams do you have? C2 or S2? Non revup?

Looking at some of the cam cards, they arent even as aggressive as my BC Stage 2 cams which idle fine, even below 1000rpm, no maf and low comp motor.

Before you make any other changes I would verify the cam install.

you dont need to adjust idle with C2's. I had them idle perfect at stock rpms.

you have other issues obviously. Do no drill the TB, thats stupid.

Your wife was cranking the car when you had the injectors pulled from the intake?

The gas needs to be drained regardless.

Are you still getting the ECM failure code? nothing will work if that code is present.....

It was actually a fuse in the wrong place that caused the ECM code. [was checking the fuses, and just got one in the wrong place].

Still not getting spark, but I do have fuel to the injectors.

The only codes was U1000, and U1001. Going to have it scanned with a Snapon tool this Monday. Should be able to tell if its a bad ecu at that time.

Hopefully I didn't miss an entry any where but I'd suggest trying this... Wolf's Idle Stability Fix.

http://www.jimwolftechnology.com/wol...BILITY_FIX.PDF


It doesn't work as well as idle tune, but helps if the problem is only the cams.

Turned out it was tooth off on one bank.

What had happened was the tiny dowel on the variable intake cam gear, had moved off the hole during installation.

The fix was a small hardened hex tool that I cut, and left just a bit longer, and reinstalled where the waaay too small factory dowel went.

This time around it was much, much easier to feel the cam dowel to go into the dowel hole in the cam.

Now the engine runs fine..............well, not at first. I made a 4" air intake for which caused much confusion with the mass air sensor. The engine would start, but die pretty quick.

I put the old factory air intake back on, and now it runs fine.

Someone said that they used bigger injectors to solve the bigger air intake problem. Others say it has to be tuned with an Uprev or something similar.

Any of you have idea's on how to fix it? I really like the 4" tube I fabbed up, but I can't afford an Uprev at the moment.

Then take off the 4" intake. With a change like that on a MAF tuned system you will need a new tune. I doubt swapping injectors would get you what you need (may help but is not a permanent solution in my mind)

Looks like you hit it on the nail about the timing being off,, thanks.

The 4" setup is already off. I need to do some more testing on everything since I basically restored the whole damned car [I rebuilt the trans as well as, well, everything except injectors, fuel pump, which I have a new Aeromotive, and struts/shocks].

I've got some pre-bent 3" aluminum tubing left over from a twin turbo project that I may use for now. Until I can afford the Uprev.