Corsica misfiring after rain

Have a flashing light? Gauges acting funny? Bad idle? Get your problems solved...
GT_Indy
Registered User
Posts: 268
Joined: Thu Apr 21, 2016 2:23 pm
Been thanked: 2 times

Re: Corsica misfiring after rain

Postby GT_Indy » Sun Nov 12, 2017 3:15 pm

Sometimes the running condition can cause the TCC to not engage or disengage 100% right, causing the slight jerking feeling. I had that problem when the IAC wasn't right on my 94 sunbird, had a slight jerking mouton every time the TCC disengaged.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Sun Nov 12, 2017 4:00 pm

Yes but my car engages and disengages the lock when I am maintaining constant speed 80km/h. Not depressing or giving more gas. I guess tcc should be locked if I am driving constant speed more than 60km/h. Does iac have any effect on the cars running if I am moving a gear engaged?

I mean if i let gas at 80km/h, does the engines speed get set by iac? Well, the when pedal is up tbi closes so its IAC then.



GT_Indy
Registered User
Posts: 268
Joined: Thu Apr 21, 2016 2:23 pm
Been thanked: 2 times

Re: Corsica misfiring after rain

Postby GT_Indy » Mon Nov 13, 2017 8:02 pm

Shouldnt be locking or unlocking while maintaining a constant speed and load condition. Should stay locked in that case.
It is hard to know the exact cause.
Here is a list of possible causes I would look into if it was me, (this is in the order that I would check them):
1) Poor connection on tcc plug at trans.
2) Poor connection at ECM.
3) Running condition causing tcc to unlock.
4) failing ECM, tcc solenoid, or gear pickup pressure switches (in trans for 2nd and 3rd, two separate ones total).
5) Internal leak in trans.

Do you have an OBD1 scanner? A "Monitor 2000" with a carterage of your year could read live data. Do you know if your tps reads properly? I know the throttle position signal will cause the tcc to unlock depending. A scanner can see if it reads 0-100% correctly.

IAC is commanded by the ecm. Only feedback is MAP and RPM in that case. The IAC being stuck open could cause it to be off or borderline on the engine value. That's the only thing I can think of that might cause an unlock if the IAC is open to far. Hard to know without a scanner to observe it.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Wed Nov 15, 2017 8:21 pm

Yeah IAC is too much open atm, drove the car 200km to my friends garage for rust operation, no problems at all generally. Idle been between 800-1500rpm depending from day. Not hard starting either since the ecu seem to deal well with the malfunctioning IAC.

The TCC engaging problem, havent faced that problem anymore, maybe it was moisture somewhere (in TCCs connection i guess). She seem to run almost perfectly on all conditions atm, even though IAC is not functioning.

Saw spare parts corsica for sell, 220€ 180 thousand kms driven, only prob was broken brake line why it didnt pass inspection. Guess im gonna buy that one. Model year is same and even color is same, meaning I can replace anything from it to my own car. Not a bad deal. Also can steal iac and oil pressure sender for first! Also easy to test the parts before moving them since the spare car is in running condition. Guessing that car will spare tons of money for me during years, since it seems like corsica has become my hobby car lol.



GT_Indy
Registered User
Posts: 268
Joined: Thu Apr 21, 2016 2:23 pm
Been thanked: 2 times

Re: Corsica misfiring after rain

Postby GT_Indy » Thu Nov 16, 2017 3:20 pm

That is why I own more than one car with the same Gen2 v6 engine. lol
I can swap parts between them and its easier to verify known faults with sensors and other electronics.
I like the Gen2 v6 because its simple and resiliant to use and abuse, plus there is only like 7 electronic things that could possibly fail and make it run bad.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Thu Nov 16, 2017 7:39 pm

Yeah, agree. Called the seller today, this one seems also to be in perfect condition, there should generally only be one problem, which is moisture it has had inside. Floors are wet and firewall leaking just like mine. Next summer gotta take carpets and other stuff off, let them dry, make rust crap for this car also and then somehow remove the mould smell from the carpets (if theres any).

I think I'll actually keep that car in running condidition and repair it for my bro who gets lisence soon. But yes, at least gonna borrow IAC from that car to check whether thats the one whats causing my starting problems. And yeah, my misfire would have been fixed in 3 hours since I would have moved everything from working spare parts car to mine instead of spending weeks and weeks wondering wtf is wrong this time lol.



Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Sat Dec 02, 2017 7:23 pm

Damn. Switched IAC from the spare / project Corsica I bought. Still experiencing hard starts every now and then. FPR vacuum line is dry. I put the new IAC in today. 7/10 starts were normal. 3 were long and required extended cranking. 2 of these long starts came when I was doing idle relearn procedure after switching IAC. When the car starts it runs just fine.

Also, put my old, not working IAC to spare corsica and fired it up. No probs at all. A bit erratic idle, but it was 100% starting ok and without cranking.

What else could make hard starts every now and then? Fuel filter clogged? Dont think im putting my intake apart just to check injectors for little issue like this...



GT_Indy
Registered User
Posts: 268
Joined: Thu Apr 21, 2016 2:23 pm
Been thanked: 2 times

Re: Corsica misfiring after rain

Postby GT_Indy » Sat Dec 02, 2017 9:41 pm

Did you ever check the fuel pressure was charging and holding correctly? I don't remember. lol
If the other car has a bit of erratic idle from the IAC that was swapped in, it sounds like it was part of the problem.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Sun Dec 03, 2017 5:38 am

Yeah the idle is much smoother and works right now.
Havent made any fuel pressure tests, I guess thats the next phase... I just need to buy a gauge for it. I guess I am gonna drive at least next summer with it like this, dont have time atm to start measuring pressures since the cat is running great for now. Just gotta do front brakes and switch the damn oil pressure switch to a new one.

Question:this spare corsica when i put it on start mode and all lights start blinking, I see red light with person who has seabelt? Is it just seabelt reminder or something else? I dont have such light on my own car. Might be missing bulb...



GT_Indy
Registered User
Posts: 268
Joined: Thu Apr 21, 2016 2:23 pm
Been thanked: 2 times

Re: Corsica misfiring after rain

Postby GT_Indy » Sun Dec 03, 2017 11:55 am

Yah that little person with seat belt says "you gotta wear a seat belt." 2 wires in the driver side belt latch that triggers it, connection closes when seat belt is used. If it doesn't then its either unplugged or has a broken wire somewhere. There is at least one plug on the floor by the carpet for it where the latch bolts to the floor pan.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Sun Dec 03, 2017 8:41 pm

Aigth, gotta take look to the dash lights again... didnt know this car knows whether I plug seatbelt or not heh.

https://youtu.be/uG5yP7M5Ttc

Heres video from today. As you see, when i let the car sit for more than few secs it wont fire up well. If i fire up right after turning the key off, no problems.

Is there somewhere fuel pump test wire or something to turn the pump on manually? So it would run until i disconnect it.

Also, is it normal, that my fuel pump only primes after FIRST time I turn power on? If I turn the key to on position in example 3 times, it only primes at first time...



GT_Indy
Registered User
Posts: 268
Joined: Thu Apr 21, 2016 2:23 pm
Been thanked: 2 times

Re: Corsica misfiring after rain

Postby GT_Indy » Mon Dec 04, 2017 3:11 am

Yah. You have a pump prime timer and then a delay timer between pump primes if you keep cycling the key. I forgot how its done. But waiting a little bit and it will prime again with a key cycle.

If it starts when you crank immediately that's good. But if it has a long start after you turn to run then wait a bit, that could mean you arent holding fuel pressure somehow. It should prime to 46 psi and hold. If it starts dropping after it primes, that's not normal.
I don't remember the exact specs but it charges to 46 psi and drops something like 1 psi every 60 seconds or so. Faster than that like 5 psi in 60 seconds is too fast.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Mon Dec 04, 2017 5:45 am

Yeah I think gotta buy that tester. One thing not going to my mind is that sometimes it starts well when warm... and most times it doesnt. Also last summer when I cleaned the iac hard starting went away for 2 weeks. And it came back right after I did idle relearn. That is something I dont understand. Since now I got working IAC. Any possibilities ecu is messed up?

Any idea how to get the pump running constantly and then try starting the car?



GT_Indy
Registered User
Posts: 268
Joined: Thu Apr 21, 2016 2:23 pm
Been thanked: 2 times

Re: Corsica misfiring after rain

Postby GT_Indy » Mon Dec 04, 2017 2:52 pm

There is a fuel pump relay that controls the fuel pump.
When it clicks on, the pump runs for 3 seconds. When its off then the oil pressure circuit is what runs the pump. Its a flip flop with 2 different run conditions.

You have the 3.1 MPFI engine? One of the relays on the firewall is fuel pump. I forgot which one though. Might be the one closest to the brake booster.
There is a 3 plug connector under the rear between the tank and rear passenger seat. Can be seen if the car is jacked up. There is ground, pump power, and float, but have to look up the colors in the book to verify which is which.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
Registered User
Posts: 49
Joined: Mon Aug 14, 2017 4:05 pm

Re: Corsica misfiring after rain

Postby Bapsu » Mon Dec 04, 2017 5:46 pm

Yeah its 3.1 multifail. :)

Somewhere I read there would be test lead somewhere near firewall to run fuelpump? Gotta take look to the relays, though those seem to work just well.

What kind of operation is it to take upper intake off? In case I need to mess with regulator. At least not job to do at winter lol.




Return to “Diagnostic Help”

Who is online

Users browsing this forum: No registered users and 7 guests