Starting Problems

[Maty]

Hello. I've been having some starting problems lately. When I crank the ignition it takes over 5 seconds easily to start, and then when it does it seems like it wants to stall or it didn't start properly.

However when I turn the ignition and put my foot on the accelerator going a little over halfway down and then immediately take my foot off slowly, it starts just fine. Can anyone give me a hand please on finding the problem. Thanks.

[DrRadar]

I assume you're trying to start it without touching the gas, and it is sluggish starting. Giving it some throttle helps it start. Do I understand you correctly?

My 99 GTP often does the same thing. If all I have to do is give it some gas while cranking to get it started, then I live with that. I don't consider that a "problem," although it may not be the design goal.

[Maty]

Yeah it works fine like that but I didn't want it to get worse or anything. Every once in a while when I start it like that (giving it a little gas) the engine makes a weird sound, it runs, but it doesn't sound right.

[Tech II]

3.1/3.4/3.8?

Any codes? Possibly TPS?

Check the throttle plate and bore for crud(clean if necessary), and also clean the pintle on the IAC.....

Check vac line to fuel pressure regulator for fuel....

[Maty]

3.1 Engine, I already took off the throttle plate and cleaned it with that carburetor cleaner, it wasn't very dirty, but still cleaned it. I'm assuming since nothing is on the dashboard there are no codes?

I checked the fuel pressure a long time ago but I wasn't sure what I should of been looking for, what should the pressure be on idle, when starting, and running? Should it be going up and down? I tried reading online but it really confused me.

[olopezm]

Cycle the key 4-5 times before actually starting the car, that will prime the fuel pump. If the car starts fine then you might want to check the fuel system (pump, filter, lines, fuel pressure regulator). If it doesn't, your problem must be somewhere else.

My car has the same problem form time to time and it got worse after I replaced the ignition switch, why? I don't know. I tried disconnecting several sensors and when I disconnected the TPS it stopped doing it. That must be my problem but I haven't replaced it...

Oscar.

[rkvons]

Did you take off the IAC valve and clean its pintle and then make sure the passage is clean?

[Maty]

I tried priming it and it didn't make a difference, what could the problem be? I haven't cleaned the IAC valve, I've never heard of it before. I'll look into it and see how to clean it.

[olopezm]

Just spray carb or inake cleaner on it and scrub it with an old toothbursh. Do teh same for the shaft on the throttle body until it's clean.

Carbon build it will cause it to not seal properly or alter the colume of air going through it causing rough idle or starting problems.

As I said before my car does the same and problem goes away if I unplug the TPS. I haven't replaced it, you might want to try the same, unplug it and see if it happens.

Oscar.

[FISH96]

one should not use 'carb cleaner' for throttle body service it is too aggressive leading to damage of coatings or other components. cleaners designed for throttle body cleaning are your best bet. same goes for MAF cleaning only use those solvents specific for that purpose. I am certain this has been covered previously in this very fine forum.
anyone know what happened to tblake or richtazz. seems they disappeared as bnaylor lost interest. although I see they are still wearing their moderator's caps.
regards and best to all

[olopezm]

Originally Posted by FISH96

one should not use 'carb cleaner' for throttle body service it is too aggressive leading to damage of coatings or other components. cleaners designed for throttle body cleaning are your best bet. same goes for MAF cleaning only use those solvents specific for that purpose. I am certain this has been covered previously in this very fine forum.
anyone know what happened to tblake or richtazz. seems they disappeared as bnaylor lost interest. although I see they are still wearing their moderator's caps.
regards and best to all

All you say it's true, however I've used it and have had no problems. I don't say that anyone else won't have problems either...

I've used electric contact cleaner on MAF's and has worked well too. The most important thing here is that the cleaner should leave no residue.

On the other hand, if you're totally sure the MAF is bad and cleaning it with MAD cleaner does not seems to help, I guess you could go ahead and try a harsher cleaner; the sensor it's bad anyway and it cannot get any worse...

I also wonder what happened to Rich, Tim and Bob. They no longer show up and I think the only moderator I see from time to time is GTP_Dad. Hope they are fine.

Oscar.

[Maty]

Tried unplugging the TPC valve and it didn't make a difference, it was still taking a while to start. I'm starting to notice now though if I let the key go before you are certain that it started, it will sometimes be running but at like 500-800 RPM's. And after a bit of the RPM needle going back and forth, like it wants to die, it will rev up to its normal idle RPM. Not sure if this is a consequence of the problem or it's because I stop cranking it before it started.

When I took out to clean the throttle plate, I went all around and cleaned everything that I could. I know I got the shaft on the throttle plate but I don't know about the IAC.

[olopezm]

You mean TPS sensor, right?



Cleaning the IAC valve is not hard at all.

Oscar.

[Maty]

I just took the IAC valve off (thanks for the picture) and cleaned it with the TB cleaner, it didn't work. Could this be an electrical problem? Like the spark plugs or coils?

Today when I started it without putting gas on it, it took several seconds, about 5-7. But when I thought it finally started I let the key go and it seemed like I missed the start. The RPM's dropped really low and then it started normally. But it started for sure before I let the key go.

On a side note they only recommend brake cleaner and TB cleaner for the IAC. Some people also use something called "Mr. Green" I believe, but most say that it's not strong enough. But everyone agreed to definitely not use Carb cleaner.

[Tech II]

I have used carb cleaner without problems.....