new motor=surging idle (skyman)

[rob90gt]

These were the mods on my car, twisted wedge heads, cbra int. e-cam, along with 24 inj. and 75 pro-m.Car ran fine no weird idle. Well oil pump locked up and aI rebuilt another shortblock only thing diff. is keith black flatops for tfs heads 30over. Now car runs fine exept coming to a stop idle surges from 1000rpm to 2000. sometimes at a stop it will idle fine? I think there was a trick about disconnecting the battery? any help would be appreciated. thanks

[SaleenGTS]

The ecamis notorious for that, especially with those heads and that mass air unit. You might check your vaccuum hoses and mak sure they aretighs and not leaking. Check your Vaccuum Tree also and make sure everythingis like it should be. What year car do you have?

Check you TPS also.

[exgmguy]

I had to give my car a vacuum leak to keep it surging at idle. I also have that *******' E-303. I just took off the smallest vacuum cap from the tree.

You can also try resetting your computer. Disconnect battery for 20 minutes.
Reconnect battery, unplug IAC motor, start car.
Adjust idle to about 700 rpm on a good tach. (The factory one is off.)
Adjust TPS voltage to .95v-.98v.
Shut car off.
Plug IAC motor back in and start the car.
Let it idle for 2 minutes with all electrical accessories running.
Shut engine off for 2 minutes.
Let it idle again for 2 minutes with no accessories running.

[rob90gt]

Thanks Guys. I havw a 90 gt. The thing that gets me is everything is the exact same on car; fuel press., tps. Only difference is block. Before I swapped engines the car idled smooth as glass. Ithought it was pretty good for an e cam after everything bad I heard. Now I'm floating in the same boat. Later

[Mach 1]

Welcome to the unexplained and notorious mystery of the inconsistent surging idle e-cam.

I had e-cam with surging idle and tried everything to fix it. re-setting this, adjusting that, EVERYTHING, even idle air spacer. Nothing worked. Swapped to a comp. cams with a 114 LSA and it hasnt surged yet.

I sold the same e-cam to my buddy, he put it in his car, and it doent surge at all.

If anyone can explain this mystery, please dont hesitate.

[exgmguy]

Ha! Thats funny. So right too!!!

[Skyman]

Yeah the E-303 surging mystery. I fought it forever. Never cured it, but its definatly livable now.

Get your timing and fuel pressure set. I found turning up the fuel pressure a bit helped. Set the TPS to ~.98 as exgm said. Remember changing your idle mess's with the TPS voltage also, so set those together.

I'd put the idle around 1000, the help the surge.

Then unhook the battery for 30 min (from what I've been told) hook it back up and let it idle for 2 min.

Hopefully that will help it out.

Skyler

[exgmguy]

The E cam causes the engine to run very rich at idle. Then the computer will go into fits trying to stabilize. That is why you can give it a vacuum leak at idle and it won't surge.

Or just get an EEc tuner or a custom chip.

[Mach 1]

I dont buy it. I tryed the vacuum leak, no help. I tried leaning the mixture, no help.
And some peple have no problems at all, from the beginning. even people with limited tuning knowledge.

I think the variable must be in the factory ECM. Some can tolerate the increased overlap of the e-cam better than others.

[rob90gt]

Thanks sky. I thought it was you who posted something on this subject way back in the day. Anyway I think I got it to where it is tolerable since I don't drive it that much anyway.I did the battery thing and it really did help some. By the way the car does seem to run real rich at idle, but when it gets up there it screams. I'l try and play with fuel press. some more.Thanks alot to everyone else Later