26 replies to this topic

[gilber33]

Alright, so this all started this morning. At home, parked outside, it was really cold last night and I had to move the car this morning. Started it up and it wouldn't want to stay running. I would start it, RPMs go to about 1500 and drop back down to 900 and then the car would sputter for a bit and then die. I had to feather the accelerator pedal for a while to keep it running. Finally stayed running, took it for a drive and it appeared to be completely OK. However, it got up to operating temperature extremely quick. Sitting outside all night and it was up to op temp in maybe 3 minutes of idling.

Fast-forward to three hours later. Try to start it again, same thing. Once it started idling it would die, eventually able to drive it and everything appeared fine. Same as before, up to operating temp in maybe 30 seconds...according to the gauge.

About 5 hours later we try again. This time, it was sitting in the garage all afternoon so it was warm. Same thing. It would turn on, RPMs drop back down and it would die. This time, sitting inside we could define a couple things. One, operating temp again increased rapidly, after sitting for about 5 hours the gauge said it was at operating temp in maybe 5 seconds, engine was barely warm to the touch. Two, the throttle was extremely laggy. You would press the accelerator pedal and it would not rev up, very very laggy. Three, we were getting very strange boost/vac characteristics reving it. It was going INTO vac was the RPMs rose. See video:



Also, the IAC would run for a minute or two after the car shut off with the keys out. Don't know if that means anything, don't know if it's done that before. Could a bad IAC not cause the car to idle? Why would the gauge say it's at operating temp when it clearly isn't?

Any input or additional information/questions, please ask. This all started today.

[Ihatespeedbumps]

Didn't watch the video, but from your description the ECT is bad. Very bad in fact.

Replace with an OEM sensor and a new t-stat and she'll start right up.

[gilber33]

What is the ECT?

[Ihatespeedbumps]

Engine coolant temperature sensor.

[gilber33]

And that will effect the running issue of it not want to stay running?

And where is this located? Below the thermostat? How do I replace that?

[Ihatespeedbumps]

gilber33, on 23 December 2011 - 11:06 PM, said:

And that will effect the running issue of it not want to stay running?

Absolutely.

gilber33, on 23 December 2011 - 11:06 PM, said:

And where is this located? Below the thermostat? How do I replace that?

Yes. Search this site for ECT replacement. It's almost self explanatory.

[Keaton85]

Buy a new one, unscrew the old, screw in the new.... right next to the thermostat. easy peasy....

[gilber33]

Awesome. Thanks guys, I will start there then.

[Tommy.]

Yea I did this on the red wagon Gabe along with the tstat and noticed a significant improvement in my idling and throttle response.

[gilber33]

Alright, some more questions. OK, so I had this issue with the car starting hard in a thread I started a while, and it was thought that my starter was going on it, intermittent long cranks until it started, and in this thread, now my ECT is out. On my way home today, just getting the car back to my house I had to stop for gas, when I tried to restart it, the car would not start, just crank. I'm getting fuel, the fuel rail is fully pressurized, battery had 12v, and I'm getting spark, we unplugged the wire from the coil to the cap and there was spark from the coil. We started towing it home, while we were towing it, my Dad threw it in fourth, popped the clutch and started it and it started right up and he drove it home, got home, and it would not start, just crank and crank and crank. Sound like the starter is done?

[Rod'sT-5]

No. The starters only job is to crank or spin the motor over. Whether it starts or not, depends on proper fuel, spark at the right time, compression, etc. Long crank times means that the starter is doing its job, something else is not. Have you replaced the ECT yet?

[gilber33]

No, the ECT has not been replaced yet. Will the ECT being shot prevent it from even starting?


And, if the starter is completely fine, why would it not start when the car is still, but fire right up when it's rolling. And when I say crank like it normally does, I'm not talking about a powerful crank either, it's weak.

[gilber33]

Would a bad CPS not allow a car to start while not moving, but if the car was rolling, allow it to start?

Basically, what would cause a car to not start when not in motion, but allow it to fire right up and drive 100% normal when in motion?

[Jardim]

Bad CPS would not let the car start period. The car needs the info from the CPS to know when to send fuel, throw a spark, etc.

[gilber33]

So if the CPS was bad the car wouldn't start whatsoever? Even if it was moving? Is that one thing I can cross off of my list?

My Dad and I are also thinking maybe the ignition switch because of the description on FCP:

Quote

The ignition switch usually has several different positions including an 'accessories' position, which allows your car to run simple accessories such as the radio while other positions, like 'start,' will allow enough electricity to start your vehicle's engine. A failing ignition switch will be problematic and may even prevent your car from starting.

[gilber33]

Anyone else have any thoughts? Car won't start when still, but with it being in motion it fires right up. We thought that it was the starter as that seemed to have been the issue before, that it was going out. We are also thinking maybe the ignition switch. The biggest thing is the start up while being towed, but will not when sitting in place, so that should rule out some.

Trying to determine other possibilities through the various sensors in the car. The crank position sensor I read that if it was bad will not let the car start but you would also lose spark, is that true? If so, I can cross that off the list.

Found these:

Quote

A less common cause is a worn starter that draws so many amps while cranking the engine that there’s not enough juice left to adequately power the ignition system and fuel injectors.

This sounds like it could be a possibility. The first thing my Dad said was that it sounds like the car wants to start, but there is something preventing enough electricity to actually start the engine (starter or ignition switch).

Quote

No spark due to a bad crank position sensor

So I can rule out crank position sensor as I am getting spark.

Found Here

[scumcity14]

I had an RX-7 that did this two different times. One time it turned out the frayed wiring to the starter was causing too much draw and was not allowing enough juice to the coils. The car would crank and almost fire but wouldn't start. would start when pop started..sometimes. eventually it blew a fusible link..

Second time it was one of the coils..it would spark but it was too weak to fire. That was a pain to diagnose because there was visible spark..(this was on the trailing ignition on a rotory though, so i wouldn't suspect coil on yours if it pop starts)

Your starter idea may be accurate..

Edited by scumcity14, 27 December 2011 - 02:20 PM.

[gilber33]

I think that's what it is too. From everything I've read, I think it's either the starter or the ignition switch. Leaning towards starter. Hopefully my Dad gets to that today so I can move on from there, whether that's it or not.

[gilber33]

Well, the starter is in and the car starts, however, it's still struggling a bit. He said that if you turn the key all the way to start it, it won't start, but as soon as you back the key off like your turning the key out of the start position, it will start. So we're going to pick up an ignition switch. It sounds like it was a combination of a poor starter and a failing ignition switch. And it's just as my Dad described it, it wants to, but it's like there just isn't enough juice for it to start completely.

[Snabb T5M]

alternator does not = starter.

gilber33, on 27 December 2011 - 04:56 PM, said:

Well, the starter is in and the car starts, however, it's still struggling a bit. He said that if you turn the key all the way to start it, it won't start, but as soon as you back the key off like your turning the key out of the start position, it will start. So we're going to pick up an ignition switch. It sounds like it was a combination of a poor alternator and a failing ignition switch. And it's just as my Dad described it, it wants to, but it's like there just isn't enough juice for it to start completely.