SOLVED IT!!! Can't keep engine runningat start up?

[hotrod3]

I can't keep the engine running at start-up and after a night of setting. When it stay's running without touching the throttle, the radiator fans turn on and the engine dies. I.m not getting any fault codes and everything seems to at the right settings according to freescan.Have already changed the TPS and reset the ICV. Could one of the quad modules be bad? When I do get it to running right,after about 15-20 minutes of blipping the trottle,it runs great!!! Edited December 7, 2005 by hotrod3

[x6gas]

Do you still have the Exhaust Back Pressure Valve installed?

If so, manually hold the EBPV open and get someone to start the car and see if that makes any difference.

It may be that the throttle jack is not opening the throttle to counteract the effect of the EBPV or there is a problem with the cross-over circuit or some other problem with the vacuum pump or the vacuum circuit.

[Vulcan Grey]

I would start by checking an intake manifold leak, maybe around the hose that is under the charegcooler. The one that goes from the fuel pressure regulator to the intake to the crankcase breather.

Then you'll need to check your IAC reading in freescan once the car is warm and at idle. it should be between 20-40 counts on the IAC at 82dec coolant temp at idle. If not the email back here. You'll need to adjust the minimum air rate bleed screw while watching the IAC counts in freescan. DO NOT try to adjust it by ear, you must use freescan.

Of course check the EBP valve as well. as X6gas said

[hotrod3]

Do you still have the Exhaust Back Pressure Valve installed?

If so, manually hold the EBPV open and get someone to start the car and see if that makes any difference.

It may be that the throttle jack is not opening the throttle to counteract the effect of the EBPV or there is a problem with the cross-over circuit or some other problem with the vacuum pump or the vacuum circuit.

<{POST_SNAPBACK}>

Ian,

I have the EBPV Wired open right now.That was my thoughts too! It still acts the same.I do know that when it does start running right,and warms up, the EBPV opens like it should. Its interesting that as soon as the radiator fans start up is when the engine starts running bad.Also the temp gauge on dash shows normal running temp. I did notice on freescan that the dash temp gauge display pegs at the moment the fans come on,while the dash temp gauge in the car is at normal running temp.I have already replaced the temp sensor under the manifold,so I know its not that.I have also done a wiggle test on the connectors.

Edited December 3, 2005 by hotrod3

[hotrod3]

I would start by checking an intake manifold leak, maybe around the hose that is under the charegcooler.  The one that goes from the fuel pressure regulator to the intake to the crankcase breather.

Then you'll need to check your IAC reading in freescan once the car is warm and at idle.  it should be between 20-40 counts on the IAC at 82dec coolant temp at idle.  If not the email back here.  You'll need to adjust the minimum air rate bleed screw while watching the IAC counts in freescan.  DO NOT try to adjust it by ear, you must use freescan.

Of course check the EBP valve as well. as X6gas said

<{POST_SNAPBACK}>

Travis,

I will try that tomorow. I think I remember the IAC count to be about 170, which definitly doesn't match, what you just recommended.I'll check for that possible vacuum leak too. I'll get back!!

[hotrod3]

I would start by checking an intake manifold leak, maybe around the hose that is under the charegcooler.  The one that goes from the fuel pressure regulator to the intake to the crankcase breather.

Then you'll need to check your IAC reading in freescan once the car is warm and at idle.  it should be between 20-40 counts on the IAC at 82dec coolant temp at idle.  If not the email back here.  You'll need to adjust the minimum air rate bleed screw while watching the IAC counts in freescan.  DO NOT try to adjust it by ear, you must use freescan.

Of course check the EBP valve as well. as X6gas said

<{POST_SNAPBACK}>

Did check it out today! IAC counts were at 40- counts at idle. I didn't find any leaks. Its wierd the temp dash gauge on freescan will all at once peg out and the radiator fans will start running, but the cockpit temp gauge reads normal.Something is all at once triggering the ECM into thinking its running hot! I have already replaced the temp.sensor under the intake,thinking that it might be the problem,but it still doing the same thing.Is it possible that I have an air pocket in the cooling system? Suggestions please? I know it has to be something simple that I'm missing.

[Vulcan Grey]

Did check it out today! IAC counts were at 40- counts at idle. I didn't find any leaks. Its wierd the temp dash gauge on freescan will all at once peg out and the radiator fans will start running, but the cockpit temp gauge reads normal.Something is all at once triggering the ECM into thinking its running hot! I have already replaced the temp.sensor under the intake,thinking that it might be the problem,but it still doing the same thing.Is it possible that I have an air pocket in the cooling system? Suggestions please? I know it has to be something simple that I'm missing.

Yeah, the dash temp sender and the ECU sender are in different locations, so you could have an air pocket. Keep bleeding the system, and make sure the overfill tank in the rear is half full.

[hotrod3]

Yeah, the dash temp sender and the ECU sender are in different locations, so you could have an air pocket.  Keep bleeding the system, and make sure the overfill tank in the rear is half full.

<{POST_SNAPBACK}>

Took out all the relays in the engine bay,cleaned connections and re-installed them. Has been running great for two days with no start up or running problems. Life should be so simple HuH! Why is it we always look for the worst case senerio first??? B)

[Bibs]

Great news, thankfully cheap news too, well done