Stalling, funny idle...

Almighty-Si · Post by **Almighty-Si** » Fri Sep 25, 2009 8:05 pm

Well I had my motor built a ways back but have been unable to drive it. Mostly due to frustration but I have ran out of ideas until now. When I had the motor built, I brought it to a mechanic due to lack of time at that moment but I did go when I had time to work on it myself (long story). When I got everything done and back in the initial start up was fine, ran rich but not a big deal, as it warmed it leaned out and was fine. The ride home the car drove fine but rolling to a stop at a sign or red light, caused the car to stall. Starting it back up caused the idle to bounce and after a couple revs it would settle back down. I got it home and took out the IACV and cleaned that up but the problem presisted. I hooked up the laptop to clean up some of the a/f to see if that may help and nothing as well though, while logging I noticed the map was reading way higher than where it would normal idle so I thought the map sensor maybe faulty. Ordered a new one and replaced it, still same issue. Ran through all the vacumm sourced to check for leaks and nothing, cleaned the throttle body and still nothing. So now I have been sitting here for months going back in my head, thinking what possibly I could have done wrong or overlook except for the valve adjustment. So I guess my question is would a wrong valve adjustment cause these kinds of problems? It's one of the things I wasn't there for so I'm not sure if he spun the crank after adjusting each cylinder or if he just set it at TDC and adjusted them all. Probable cause or am I just grabbing at straws?

xenocron · Post by **xenocron** » Sun Sep 27, 2009 8:22 pm

Need more info on the setup...stock motor?

Almighty-Si · Post by **Almighty-Si** » Mon Sep 28, 2009 9:42 am

B16 Bored to 81,50 CP 9.0:1 pistons Stock head Was in the garage yesterday to check the valve lash and there was zero clearence. I actually had to crank the adjustment screw on the valve 3 turns before I could get the feeler gauge in there.

xenocron · Post by **xenocron** » Mon Sep 28, 2009 7:10 pm

Too tight of an adjustment would open the valve too early and close it early...but it would give a higher lift. I think you would notice more issues than just a stalling idle...but let us know how you make out on the valve adjustment and if it cures your issue.

Almighty-Si · Post by **Almighty-Si** » Mon Sep 28, 2009 9:08 pm

Stalling, high vacum reading, fluctuating idle...it's all the problems im seeing.

Post by **Gaskleppie** » Tue Sep 29, 2009 4:04 am

Maybe a wrong connected purge valve? If the lines are connected after the throttle valve, it can give strange things. The purge lines must be connected before the throttle.

Almighty-Si · Post by **Almighty-Si** » Tue Sep 29, 2009 7:32 am

Gaskleppie wrote:Maybe a wrong connected purge valve? If the lines are connected after the throttle valve, it can give strange things. The purge lines must be connected before the throttle.

I will check this, I am most certain though it's connected correctly. I have run through all my wiring and hoses atleast 25 times...LoL...thanks ! Anymore ideas please leave your input, I'll try anything at this point.

Almighty-Si · Post by **Almighty-Si** » Wed Dec 02, 2009 4:34 pm

Well the car is still not running. From the looks of it, it seems to be getting too much fuel. I did the valve adjustment, checked for stuck injectors, swapped fuel pressure regulators, pulled a ton of fuel from my maps and still getting tons of fuel vapor out of the exhaust. Any other ideas?

thething96 · Post by **thething96** » Wed Dec 02, 2009 5:27 pm

Maybe a vacuum leak(not from hoses, but from manifold or tb)?

Almighty-Si · Post by **Almighty-Si** » Thu Dec 03, 2009 11:49 am

Throttle body never came off the intake manifold and I torqued the manifold onto the head myself and checked it again, everything just fine there.

Almighty-Si · Post by **Almighty-Si** » Thu Dec 03, 2009 7:33 pm

Well I got the car to run, not good by any means but it did run, I had to pull 95% overall fuel trim to do it. It got the car running long enough to check the maps and I noticed that the cels were reading from the 21psi part. So looks like my brand new MAP sensor is the problem.

Post by **Gaskleppie** » Fri Dec 04, 2009 2:08 am

Do you have a imitation GM map sensor? If so, your wires are connected wrong. A real GM sensor is wired different compared to the imitations.

Almighty-Si · Post by **Almighty-Si** » Fri Dec 04, 2009 10:24 am

No, I have the DIY 2.5 bar Motorola sensor from xenocron that Chris put together for me. It's brand new which is why I never went back to it as being my problem, just noticed it yesterday when I pulled all that fuel out to get it running. Oh well guess I have to get yet another...

Almighty-Si · Post by **Almighty-Si** » Sun Dec 06, 2009 11:50 am

Threw in a new factory replacement MAP sensor from the local autoparts store yesterday and wouldn't you know it...started right up and runs pretty smooth. According to the vac/boost gauge there is a small vacuum leak present as it's reading from the -18hg/in but I should be able to narrow that down pretty easily.

xenocron · Post by **xenocron** » Mon Dec 07, 2009 1:03 am

Almighty-Si wrote:No, I have the DIY 2.5 bar Motorola sensor from xenocron that Chris put together for me. It's brand new which is why I never went back to it as being my problem, just noticed it yesterday when I pulled all that fuel out to get it running. Oh well guess I have to get yet another...

This is why I dont like glueing these little things together myself