rough idle, stalling

drq_92 · Post by **drq_92** » Sat Feb 24, 2007 3:11 pm

Hey guys, I could really use some help here. I have a 1990 beretta 3.1 auto. The problem im having is firstly the car seems to run way too rich. Second the idle has some problems, when the car is in park it will rev about 900-1000rpms with a bit of studdering, but as soon as you press the brakes it go to 1100 then juss fall to 500rpm n pretty much stall. Ive changed the coil packs and ignition module, map sensor, looked over all vacuum lines and plug the ones going to the evap canister, cruise control, and vacuum tank, replace the ecm. Then using Carb medix (CLeaner) i went over all the gaskets and vacuum lines with no change in idle. Hooked up a vacuum pressure meter and got a reading of 15, so i could really use any help, im out of ideas.

Thank you. Oh and unpluged the tcc, check the fuel pressure and egr. All where okay.

drq_92 · Post by **drq_92** » Sat Feb 24, 2007 3:24 pm

Sorry theres abit more info i should give. The car has 260,000km on it, i dont get any codes other then once in a while code 45-rich exhaust. Also i changed the o2 sensor...and check all plugs which all 6 of them where black, but they are still good.

Jeff P · Post by **Jeff P** » Sun Feb 25, 2007 2:51 am

The parts you replaced...did you replace them with new parts or known good? A bad coolant temperature sensor can cause a rich condition. Does code 45 ever set at idle? If so, that may indicate a bad TPS (which could explain some other problems too). Your fuel pressure was below 47 psi, right? That's weird about the idle dropping when you step on the brake - I've never had that happen. The fuel pressure regulator could also cause some problems, but I haven't had to deal with that before so can't advise on it.

drq_92 · Post by **drq_92** » Sun Feb 25, 2007 1:01 pm

hey Jeff, the fuel pressure was 38psi with the regulator, 43psi without, so i believe its doing its job? Also all those parts are either new or off a beretta that works 100% so there good. The Vacuum tested out at 15, which im pretty sure is really low isnt it? Other then that code 45 appears after letting it run after it gets warmed up and reving it. That code also has not reappeared since plugging the vacuum going to the evap canister. Other then that Im lost, do you think it could be electrical?

Jeff P · Post by **Jeff P** » Tue Feb 27, 2007 1:54 am

I've actually never heard the proper spec for vacuum, so good question The problem could be electrical, I guess, but I wouldn't know where to point you except wiring near various sensors. Maybe you have some injectors that are running rich? That doesn't explain the idle problems, though...I had considered that the drop in idle after pressing the brake pedal could have something to do with the current draw from your brakelights, meaning maybe a bad voltage regulator but....All I can say is at this point I'd be spending a whole lot of time with my car testing everything and eliminating things as problems one by one starting with the most likely and easiest to test.

drq_92 · Post by **drq_92** » Tue Feb 27, 2007 2:36 pm

Alrighty Jeff thank you very much for the reply, i will find the problem, im thinking its some electrical...the guy i bought the car off of was a tool. I know he did alot of crap to the car so im goin over every single electrical wiring, plug etc..So far alot of shortcuts and problems. So now its just a matter of what is the problem, i might juss rewire the whole car lol. Iunno thankx again.

drq_92 · Post by **drq_92** » Tue Feb 27, 2007 2:39 pm

Oh by the way do you know where i could find a complete wiring diagram of the 3.1l?

getz172006 · Post by **getz172006** » Fri Mar 02, 2007 6:34 pm

yea i got a 1990 beretta 3.1 auta and im tellin ya it' s probally the wiring i have the same probleme too cant pinpoint it tho

getz172006 · Post by **getz172006** » Fri Mar 02, 2007 6:35 pm

and id like one of them wiring diagrams too so let me know if you find one

Jeff P · Post by **Jeff P** » Sun Mar 04, 2007 4:13 am

The manuals in auto parts stores are useless as far as wiring, so I'd highly recommend getting a factory service manual put out by Helm. Either try to find one at a dealership and copy pages from it, or search on eBay. Try to get a 1990 manual because 1991 will have several changes (and be almost completely different for interior wiring).

drq_92 · Post by **drq_92** » Sun Mar 04, 2007 11:28 am

Well the car is still not running right, ive fixed every wire under the hood, so the only thing left is interior. I guess today ill be pulling the dash. As for those books, my brother actually has book 1 n two beretta/corsica service manuals...and to tell you the truth they are awesome for just about everything other then diagrams...maybe some like them but i find them still with little detail. Ill give you guys an update if anything changes, right now theres only 3 things left on my list before the car goes by bye lol. One the interior wiring, Two taking off that pnenum(i have no idea how to spell that) and physical lookin at all the lines in there. and last buying a new IAC value.

Jeff P · Post by **Jeff P** » Mon Mar 05, 2007 4:59 am

Sounds like fun, I hope you find something

"Plenum" is probably what you're talking about...

ifixalot · Post by **ifixalot** » Thu Mar 22, 2007 12:50 pm

Check each fuel injector with an ohm meter. Each should measure about 12 ohms. Anything like 4 ohms means that injector is bad and won't allow enough fuel. The ECM makes the other injectors shoot more fuel to compensate. When you step on the power brake, you push a little air into the motor and the mixture gets a bit leaner and the motor revs. I'm not sure why it almost dies after. Anyway something to try. These cars injectors ahd a habit of going bad.

circlegtz · Post by **circlegtz** » Thu Mar 22, 2007 10:27 pm

drq 92 i just read all of this and it hurts my head did you check for an internal vacum leak like a leaky lower intake. start the car pull the oil fill cap wile its running does it stall does the idle go up put your hand over the oil fill hole does it have suction if it does bad lower intake gasket the reason it stalls when you hit the brakes is beacuse the brake booster uses vacum i could be off the wall but you could have a bad brake booster is there any hissing when you the brakes if so bad booster also check the map sensor should be rite around 1 volt at idle and around 5 volt at w.o.p (wide open throttle) if i can help any more just ask
circle gtz

drq_92 · Post by **drq_92** » Mon Mar 26, 2007 10:37 pm

well guys thankx for all ur help, everying possible was done with this car trust me on that one. What ended up happening was we had a good couple snow storms here in ontario and I busted out my 2000 chevy blazer zr2 4x4, n let me tell u that truck never dissappoints, always starts right up never quits and doesnt get stuck lol. So originally that beretta was going to be my new car n i was going to sell the blazer...but after driving it again i took a full day off and striped the beretta right down to the bone...every part, panel all mine lol. You might think thats a stupid idea but my brother has 3 other berettas so now hes set lol. Anyways its scraped...yeah its sucks but my truck is juss way too fun.

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