no start after boost leak test

[jamel16]

Hey guys, I have a problem that I am stumped on. First I noticed I had a real bad vacuumn leak right under the throttlebody area near the isc. I did the boost leak test with the soapy water to verify this. Well I removed my throttlebody replaced all gaskets, removed and cleaned the isc and reinstalled all the components. After that I did another boost leak test on the manifold side and noticed it held up to 30 psi.My problem is after I reconnected everything and triple checked my work, now the car will not start, I've checked fuel, spark and airflow and all seems well. I did replace the seals on my injectors too. Is it possible that I put the isc in wrong or when I was using the soapy water solution, it got on some electrical connections. Sorry for the long post, but I need help, too much blood ,sweat, and tears invested. Thanks in advance

 

[bpestilence]

Try cracking the throttle when you start. If it starts when you do that, you know there is something wrong with the ISC.

 

[jamel16]

Yeah, when I give it some gas while starting, it will start, but soon as I let off the gas it will die. The Isc was working fine, when I removed the throttlebody, is it possible I put it in wrong?

 

[cmptrphreak]

Did you take off the TPS ? Maybe that wasnt installed right. Double check all your electrical connections and vaccum hoses.

 

[jamel16]

No, I never removed the Tps sensor, I always thought that the isc controlled the car after start up. Is it possible that a bad isc will keep the car from starting? Also I have done the vacuumn delete mod too.

 

[turbosax2]

Did you just do the boost leak test from the throttle body elbow or did you do it from the turbo too?

 

[DKneble]

It could be that it won't start because you put everything back together correctly! You said you had a bad vac leak prior to the reassembly which could have been enough of a leak to let enough air in to start the car and idle.

Somebody correct me if im wrong here but if there was a nasty leak there then the biss screw was probably turned way down to try to keep the idle down. In which case try to back it out a couple turns and start it.

If that doesn't work then I would say the ISC is dead

Dave

 

[meliketoball]

Maybe your throttle cable or plate is just completely shut or dirrrttay.

 

[DKneble]

meliketoball- thats also a good possibility. i know everytime i disconnect the throttle cables it takes me a few minutes to get the right tension on them again.

Try this- Put the biss screw in about its half-way position so you have some play up and down to fine tune with later if needed. Loosen but don't remove the two bolts holding the throttle cable bracket on the intake manifold and slide the bracket just until you see it start to rotate the TB open and tighten the bolts just enough to keep the bracket from moving. Start the car. It should be idling a little high. Now hold the bracket with one hand and loosen the bolts again. Let the bracket start to slide back so its closing the TB, until you get to the idle RPM that you want. On my car I can do this by sound so I don't need to check the RPMs but if you can't tell then have a buddy read them off to you from inside the car. Now tighten the bracket bolts down snug. Turn off the car and let cool for a little, then try restarting. Adjust biss if neccesary after driving it a bit.

Thats my way of doing it, theres probably a better one but this ghetto method works for me.

Dave

PS - good idea to check the TPS then too and adjust if needed.

 

[jamel16]

hey guys, well I replaced the ISC with a new one ( black revised version), replaced oxygen sensor, adjusted TPS sensor, did another boost leak test, replaced Biss oring. Now before the car wouldn't start, now it starts but it idles high to 2500-3000 with a slight idle surge. I have tried the biss adjustment with no luck, I can't get my base timing to *5 degree because of the idle. I am stumped, is it possible my cas is 180 degrees off. It can't be my throttlebody because during my rebuild a 1000 miles ago, I had that sent out to throttlebodypower.com to have the premium service rebuild done. Does this sound like ecu failure, I'm not recieving any cel codes. I am really about to give up on this. Also I have the old school safc with the knob adjustment and when I lean out the 2400 rpm setting the idle decreases and the surge slows down. I am clueless on this one. I need help. Sorry for the long post and thanks guys for your input.