1trucavalier Posted March 28, 2003 Report Share Posted March 28, 2003 Okay I am still having the problem of the car cutting off. Its not tcc switch related cuz it does it in park. I can't figure this out. I changed the crank sensor finally and WOOOOOW! The car drives better than it ever has (thanks Chris and Idbeast)!! I still though can't figure out what the heck is the matter. The car cranks immediatly on the first turn of the key with no pumpin gas or letting the starter roll. I already replaced the injectors so I know its not that. When its about to cut off the car kind of rev's up down up down up down the it just shuts off. I then turn it back on and it fires up. Could it be that I just have to get Jeff's chip or what. I have replaced almost every sensor except the one on the top left of the upper manifold. I did notice though that when that pigtail is unplugged your car will not stay on at all unless you have the gas applied. When i plugged it back on it keeps an idle without gas. I am gonna replace that top sensor today. any suggestions would be appreciated! ty Oh yeah what is the sensor that sits on top of the upper manifold on the TGP left side. Quote Link to comment Share on other sites More sharing options...
TGPilot Posted March 28, 2003 Report Share Posted March 28, 2003 When its about to cut off the car kind of rev's up down up down up down the it just shuts off. I then turn it back on and it fires up. I don't know the history of the car but, I almost think I would investigate the Idle Air Control Solenoid... 8) Quote Link to comment Share on other sites More sharing options...
1trucavalier Posted March 28, 2003 Author Report Share Posted March 28, 2003 you mean the aic? that goes in the tB. I took it out cleaned it up and put it back. I will get one this evening. I will try any flukin thing. There is not much more to replace. What is the sensor called thats in the upper manifold on the left side?????? Quote Link to comment Share on other sites More sharing options...
TGPilot Posted March 28, 2003 Report Share Posted March 28, 2003 I am not saying to rush out and buy an "IAC" solenoid, but I am curious to know now if your problems started after you "cleaned" the IAC? If you are facing the front of the car and looking at the alternator side (Front) of the motor...there is a sensor that threads into the intake plenum. This is your MAT (Manifold Absolute Temperature) sensor.... 8) Quote Link to comment Share on other sites More sharing options...
1trucavalier Posted March 28, 2003 Author Report Share Posted March 28, 2003 well i have replaced all sensors but MAT <---- (thanks) and aic. They are the only left so I might as well get rid of them. It was doing that before i cleaned it so if it is that i won't know until i replace it. Quote Link to comment Share on other sites More sharing options...
1trucavalier Posted April 1, 2003 Author Report Share Posted April 1, 2003 replaced the aic and that wasn't it ! now whats left is the ignition mod, and mat sensor <---- which you can only get at the dealer $36 . Hopefully one of these will be it. ty and any more info will be appreciated. Quote Link to comment Share on other sites More sharing options...
Jeff M Posted April 1, 2003 Report Share Posted April 1, 2003 Well, I am going to take a stab at this since your not getting results fast enough. First if the IAC was moving/engine speed going up and down, unplugging it and the engine idled flat then it was ok, the IAC is not the cause but the effect as it tried to compensate for the real problem: the cause is something else. Assuming it starts and will idle for a time with no roughness and even run down the road with some boost showing the fuel pump and fuel filter are good enough for that. First is the invisible PCV valve hidden in the rear valve cover, seldom gets replaced and can cause engine idle hunting. Next I would say to check the fuel pressure regulator just to be sure since it’s a simple test/common issue, find the vacuum distribution block on the top of the throttle body, find on that block the first vacuum which is closest to the front of the engine bay, follow it down to just under the upper intake, and where it turns into a rubber “Tâ€Â, pull the rubber Tee off of the top of the FPR that sits in the middle of the end of the fuel rail. If you see gas dripping then there is one problem, to further check this if no fuel dripping, put another vacuum line onto the port of the FPR and suck on it, it needs to hold a vacuum if good, if not then well, bad!! Next would be if your engine dieing happens after a time, this would lead me to think that one or more injectors is shorted out, common for any original injector, or any Multec made before 1993 when they fixed that design flaw. Shawn once did up a procedure to check the injectors without taking off the upper intake, but have not seen that in a while, and as busy as Shawn is not sure if he would be able to get that going again. Last items less likely, Stop Lamp Switch, the engine will stall when your foot is on the brake and engine at idle, easy test is to come to a stop with your foot on the brake, no stall then come to a stop by rolling slowly on a small hill or use your parking brake to stop you slowly to test the stall. If it stalls then something else, though the stock chip and only other updated chip have a condition that once you come down below about 3.4 mph the engine will stall/o2 will go rich, idle fuel is not matched to cruise fuel tables in both of those chips and can cause stalling. Always a good idea to check the ohm reading between the engine and engine cradle/sub-frame, should be over 150 ohms, if not this will cause problems including taking out the alternator which in turn allows the battery to fail. Maybe the AC compressor is frozen and when the AC or Defroster is turned on it loads the engine enough to stall it. Very last is what others have shown and that is some wiring problems in the fuse/relay panel in the engine bay on the passenger side; when your engine is idling I would just wiggle all the fuses to see if it effects engine idle, even grab some wires under it to get it to act up. Or the ECM could be bad, some of this caused from running shorted or nearly shorted injectors for too long, or the Form-a-Coat is pulling off a circuit trace on the board. Pull off the crankcase breather tube at the front valve cover, rev the engine and hope there is no vacuum in the hole when you put your finger over it! Well, gotta get back to things, much to do every day, but hope something here helps, at least you will have checked a lot of areas that are likely to be the cause now or later, and know what to do then as well. Jeff M Quote Link to comment Share on other sites More sharing options...
1trucavalier Posted April 1, 2003 Author Report Share Posted April 1, 2003 #1 if i remove my IAC/MAT sensor pigtail the engine will cut off immediatly without gas being applied (is this good or bad?) #2 my injectors have been replaced #3my vaccume hoses have been replaced with silicone units #4my ecu has been replaced #5 when i replaced my injectors I had the fpr and all hoses off and I did not have any fuel in them I have not replaced the pcv valve or the stop lamp switch they are getting done tonight. I will post the results in the morning. ty! Quote Link to comment Share on other sites More sharing options...
1trucavalier Posted April 2, 2003 Author Report Share Posted April 2, 2003 nope not fixed yet! went out to the car and the damn batter is dead AGAIN!!!!!! GRRRRRRRRRRRRR!. all the cables and grounds are corroded to hell and half salt on them. I went to the dealer and they are $43ea for the + and the negative is discontinued. I told them while I that I would back later. <-------- Now off to circuit city. Quote Link to comment Share on other sites More sharing options...
1trucavalier Posted April 7, 2003 Author Report Share Posted April 7, 2003 can you say head gasket!!! now i have to take this mf appart again grrrrrrrrrrrr!!!!! That why I would never get an decent idle. I got lots of water coming out the tailpipe also. Quote Link to comment Share on other sites More sharing options...
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