cudabnu

90 3.6 into a 80, Patrick motorsports conversion wiring, flywheel and throttle cable. Also has complete 95 993 exhaust.
New temp sender installed, New crank position sensor installed and adjusted.
Pulled each coil to make sure both were working individually, and they are
New belt installed in the dist, new caps and rotors.

Car will fire up at first crank, rev to about 1200 rpm, then instantly start to stumble until it dies all within a few seconds

If I step on the throttle and keep it about 1000 rpm it runs good, revs very nicely, but even when warm will just not idle.

I've cleaned the ISV and AFM and confirmed the ISV is working, and can hear it doing it's job when trying to start, alos confirmed that the TPS idle and WOT are both working and pinned them out to the DME (same with the ISV).

Just need ideas of what else to check or to test.

Steve Weiner-Rennsport Systems

Did you check for vacuum leaks????

J richard

+ 1 on the vacuum leak, or even a missing breather hose. The 3.6 has a bunch of hoses that go between the back of the injection to the oil console and to the charcoal canister I would get out the PET diagram for the donor car and start counting holes and hoses...

cudabnu

I'll give that a check, I have the 2 big ones that go to the oil tank ( a 993 oil tank is installed), then the 2 smaller hoses on the drivers side, top is going to the charcoal canister, and the next one down goes to the brake booster, maybe there is a leak to the brake booster line. I bought the car as a semi roller that had a 993 body kit that was raced with a 993 3.6.

Thanks, that gives a few more avenues to go down!

cudabnu

Here's a pic of the installed engine.

J richard

Yes double check, I could be wrong but as I remember there are THREE hoses to the tank, two big one little, also check to make sure that the oil tank is sealed, both the cap seal as well as there is a vent with a check valve pressed into the top of the tank. It has a rubber elbow off the top of the tank. I had bought a used tank once and for some reason the vent was pulled out, basically a built in vacuum leak drawing through the tank. That took me some time to find...

thats going to be a fun little hot rod...

cudabnu

Thanks, I know I made a quick check and 1 of the hoses (the smaller one tot he engine) does not have a hose clamp, and I remember the fitting on the 993 tank being a little smaller than the ID of the hose, so with any luck that is the problem. I'll pick up a new clamp tomorrow and see what happens.

Here's a few more pics of the project.

cudabnu

That did the trick, just put on a hose clamp, and she fired right up and started to idle nicely. Just got my NBD switchable chip today in the mail too. I still need to get the brakes finished, adjust the clutch cable and adjust the accelerator cable, then get it back to to the painter to finish.

Thanks for the help, I probably never would have thought it'd be something so simple.

J richard

Cool! Glad to help, post up some more pics when you get it together!

Ps: dig the VDub sign, classic!

Steve Weiner-Rennsport Systems

I'd also suggest you rethink your front oil cooler installation.

As pictured, very little air can get through the cooler since its mounted far too close to the body. This results in high oil temperatures and thats avoidable.

peritus

I got Steve W's chip and that solved it - but mine is a VRam

...mine idles like a champ....and its for sale (plug) hee hee