Engine stalls after starting when warmed up

[cayman]

Not sure what the issue is but first, I've been having problems with the idle dropping to near stall, then coming back up to 550 or so, then cycling back and forth a couple of times before finally settling on normal idle when I push the clutch in and coast up to a stop. Now, when I stop and shut the motor off to go in to a store, I come back a few minutes later and start the engine, it will stall unless I baby the throttle for about a minute. It almost acts like a fuel injector is leaking into a cylinder and flooding it while its shut off for awhile. Doing a search revealed suggestions for the idle issue at a stop ranging from changing out the battery (battery is a 2 1/2 year old Interstate Magnum) to changing or cleaning the IAC, which I've done. Also pulling the PCM plugs for a while, then go back through the relearn process (which I've done also). I don't know if the near stall at a stop light and the hard to keep idling issue after the car has sat for a few minutes are related or not. Anyone have of either/or of these problems?

 

[ViperGeorge]

I would swap out the IAC. Maybe you can borrow one from a fellow member in your area.

 

[uvbnbit]

Adjust "linkage" screws?? I forget what you call 'em.

 

[Brian GTS]

Is it a Gen I car? If so, could be as simple as adjusting the throttle linkage since there are dual throttle cables. I had problems very similar with my 94 and that fixed it up...easy fix by the way.

I also had issues with my 97 GTS stalling after starting. I had to work the pedal to keep it running. That turned out to be the battery but yours is relatively new.

 

[cayman]

Interesting comments by all. I read about the linkage deal in a search. I haven't messed with the linkage since I put the Roe SC on 8,000 miles ago so I can't imagine that would be the issue. This is a '98 RT/10. IAC was replaced about 1,000 miles ago because I screwed it up polishing it on a buffing machine. I also took the new one apart last week and cleaned it thoroughly, although it didn't need it. Even though the battery is only three years old, I'm still kinda leaning that way considering the car sits quite a bit and I don't have a battery tender hooked to it. This issue actually started right after I changed out the rear seal and replaced the clutch. I disconnected the battery before working on it. That's the reason why I thought it was a PCM relearn issue so I disconnected all three PCM connectors and went back through the relearn process. I've cycled it through four or five times now (take the car out for a spin, bring it back, shut motor off, take it out again next day). The idle issue seems to be more pronounced after the engine warms up.
Another interesting tidbit is I hooked a fuel gauge up to it, turned the ignition key on, let the fuel pressure build up, turned it off and watched the pressure. The first time I did it, the pressure leaked off after about three minutes. I started the engine and shut it off again and repeated the pressure test. This time the pressure maintained after shutting the key off. I'm alluding back to a leaky fuel injector. I've had this happen before on a fuel injected single throttle body setup on a Porsche but the viper is a direct port fuel injection. Can a fuel injector leaking in to just one cyclinder cause these issues? Not so much while the car is running but after it's sat a while and it becomes hard to maintain idle initially at startup (fuel puddling in the cylinder, thus overly rich condition)?

 

[Brian GTS]

Hmmmm...not sure about the fuel injector. The stalling on my 97 due to the battery was from a dead cold start up and would usually improve once the car was running. My advice would be to contact The Viper Wizard and get some feedback from him before spending cash on a new battery or doing anything else. He may have some insight on the problem.

 

[GTSnake]

2.5 years on a battery is not that new. I go through a new battery every 3 years on the dot.

 

[Fast Viper Dan]

My first battery went bad after 1 year.
You won't know unless you try. Sounds like that's the problem.

 

[cyaford]

I had those problems. Got a new battery and all was good. One year later, same problems emerged. Got a new battery AND a tender and I've been problem free for over 2 years.

 

[cayman]

Update: Took the car to work today with no issues. A couple of drops in the RPM but came right back up and leveled out. Stopped several places coming back home and it started and idled good each time. Go figure. Maybe the relearn process took a lot longer than usual. Of course sure as I type this, I'll drive it this weekend and have the same issues pop up again!

 

[99 R/T 10]

Is your car a Gen I? I had a similar issue with my old 96. Disconnected the computer to reset it, problem never came back. Might want to think about putting a charge on the battery too.

 

[bluesrt]

no codes?-- vacume leak?