Here's what my car is doing: It starts fine when cold (ie: after over night sitting) or when it's hot and it's shut down and started up again right away. But if the engine is warm, and it been shut off for something like 15-20 minutes, sometimes it requires excessive cranking before it catches. When it does you can smell that it's running very rich and it sputters a bit before running smoothly. All other times it starts and runs great.

I sent out my injectors to Cruzin and Rich just got back to me saying the injectors flow tested fine and all within 2%. So I think I can rule out the injectors. What else would cause this warm starting problem? Has anyone else been able to solve it? And what have you looked at? I'm thinking maybe a faulty CTS but I'm just guessing. Unfortunately the plenum and fuel rail and all that are still off so I'm unable to run a scanner on it right now. Any suggestions are welcome.

 

what is your TPS voltage set at? and what about your plugs also? setting/changing those made my car start better. and I was having the same problem.

 

The TPS is within in spec (according to Craig Moates software) and the plugs were changed last spring (Rapidfires). So those should be all good.

 

have you checked you IAC motor? that could make a difference, mine was stickin at times. the computer had it open as far as it could go, but it was stuck almost shut. and it didn't stick as much when it was cold. you might wanna look at that too?

 

Good call, I was thinking this too. I figured it's gotta be one or a combination of the following things, so I think we're on the same train of thought:

1) MAT/IAT
2) CTS
3) IAC valve

I've got the throttle body at my house and I have taken the IAC out of it yet. I will do this on the weekend. What will I be looking at? I mean, how will I know if it's sticking or not functioning right...please tell me it doesn't have to be connected to the car to diagnose?

 

Don't forget about the cold start injector. That will pulse unless its own CTS reading is below a certain amount. You may have a leaky Cold Start injector, as it is tied into the fuel rail...Or you may have a bad Coolant sensor switch for it telling the ECM that the engine is cold out.

The IAC is my next guess...

 

From what I understand the cold start has it's own temp sending unit. I'm thinking if the price is reasonable, I replace that one and the CTS and then see where I stand.

I just got off the phone with Rich at Cruzin and he pressure tested all the injectors including the cold start and they all came out fine, no leaks. So at least I can eliminate that possibility.

How can I diagnose the IAC though? Does anyone have thoughts on that?

Thanks to everyone so far, you've been a great help.

 

I have the EXACT same problem!!!! Let me just say, have fun!! I didn't send out my cold start injector like you did, I should have... I am going to check my cold start injector for leaks, or simply get rid of it completely. Another thing I have to check is the MAT sensor, I have a resistance to ohm chart to check the operation. I am thinking that is the problem... I had my IAC cleaned, plugs changed, fuel system flushed and computer changes.. and i helped none what so ever.

My recommendation is to check the MAT sensor while the plenum is off.. or simply change it for preventative measures. It shouldn't be that expensive.. I am guessing 30 bux or something.

 

Thanks Nathan. I've already ordered a new MAT and CTS and they were both $30 a piece. As well as a new IAC motor. I sure hope this works.

 

I think the new IAC motor was a waste... but oh well... hope you find it.. or I ope I find it, so we can both get the problem solved... its quite embarassing when you want to start the car and it takes way too long, as well as the burnign oil at the start.. oh well...