Car is breaking up bad at 4,500 rpms

[superorange]

So tonight while driving I break boosted the car in second for a bit too long and when I let the brakes go the car broke up and fell on it's face. Tried to just get on it again same results. Hooked up the computer and started looking at the car on link. This I what I have gathered so far please help me from here. 1 my tune seemed to change. Two my volts are low and under wot I'm seeing 11.9 volts. On the wideband the car seems fine. Its like the car is misfiring or something. I have brand new plugs. I think my fuel pump may be bad. It is a supra 260. I have a Wally 250 ready to go in. Should I try that first? Also the voltage issue has been a problem since I've owned the car. I just replace the speaker wire I had for my alternator with 6 gauge marine wire and that didn't solve it. What should i do about the voltage issue? And what should I do about the situation in general? Please and thank you. I had 3 local Dsm ppl check it out and have no solution.

 

[fede]

Hey adam, I saw your car last night and we are gonna try to get together to help you out. I think you should check : 1 coil pack. 2 try to lower the boost and see if the car still acting up at lower boost. 3 change the fuel pump.

 

[Chicken Patty]

My main concern here is your voltage. Should be a steady. 13.7 or higher. Lacking the proper power can also be causing this break up. Not to mention, your pump is not flowing what it should. Other than what Freddy said, I think your voltage issue is your main problem right now.

Do you have another alternator to try? If not test that one, it could be charging a lot less than what it's supposed to. Taking it off on your car is super easy.


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[superorange]

Thanks guys !!! I can see about picking up a satarn alt at u pull it today. And I have a grinder so I can even modify it to fit. I'm gonna go to Garry today and get the install kit for the fuel pump. And we can go from there.

 

[Cesarlcase]

I used to have a similar problem with the voltage. I used to get 12.5 volts and it would steadily go down, changed my alternator and it was at 13.3 bought new terminals and cleaned the battery post and It's at 13.8 14 volts. Make sure the alt belt isn't damaged or loose

 

[Chicken Patty]

Keep us posted Alan.


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[superorange]

Which Saturn alternator should I be looking for again?

Hey adam, I saw your car last night and we are gonna try to get together to help you out. I think you should check : 1 coil pack. 2 try to lower the boost and see if the car still acting up at lower boost. 3 change the fuel pump.

Thanks man. What should I look for with the coil pack?

 

[Chicken Patty]

I have a coil pack on my car that you can try but I have to take it off, still installed but I'm not using it since I am using my COP setup. I can't take it off today though.


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[Indian]

Thanks man. What should I look for with the coil pack?

Pull all 4 plugs, and see if 2 of the 4 are fouled, Or test the resistance.

 

[superorange]

Pull all 4 plugs, and see if 2 of the 4 are fouled, Or test the resistance.

Will do as soon as I get home from work.


The car drives fine under cruising throttle and under 4500 rpm btw

 

[Calan]

My main concern here is your voltage. Should be a steady. 13.7 or higher. Lacking the proper power can also be causing this break up. Not to mention, your pump is not flowing what it should. Other than what Freddy said, I think your voltage issue is your main problem right now.

Do you have another alternator to try? If not test that one, it could be charging a lot less than what it's supposed to. Taking it off on your car is super easy.

^ This.

Low voltage causes all kinds of strange problems, not the least of which are misfires and lower fuel flow.

 

[superorange]

I have a coil pack on my car that you can try but I have to take it off, still installed but I'm not using it since I am using my COP setup. I can't take it off today though.


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Thanks bro just lmk when.

 

[Chicken Patty]

Thanks bro just lmk when.

Yeah bro just gotta find some time after work to pull it off. I'll keep you posted. Let me know how the alternator swap goes.

 

[superorange]

Ok day one update. Ended up just getting a new stock alternator. Before installing it I used a voltage tester to the battery and read 12.8 volts. After the install I did it again and the now reads 14.8 at the battery. The car started up faster than it ever did before so I think it helped for sure. The car was running really rich and idleling kind of high so I decided against driving it until it can be looked at on link. I also checked the spark plugs and they were still gapped propperly and not fouled. I also went ahead and ordered an install kit fit my 255 which should be in Thursday or Friday. Well see what happens according to link and go from there.

 

[Chicken Patty]

Ok day one update. Ended up just getting a new stock alternator. Before installing it I used a voltage tester to the battery and read 12.8 volts. After the install I did it again and the now reads 14.8 at the battery. The car started up faster than it ever did before so I think it helped for sure. The car was running really rich and idleling kind of high so I decided against driving it until it can be looked at on link. I also checked the spark plugs and they were still gapped propperly and not fouled. I also went ahead and ordered an install kit fit my 255 which should be in Thursday or Friday. Well see what happens according to link and go from there.

Just get the pump on and then we'll check it out with LINK. I think your problem is probably fixed at this point based on your voltage readings, especially if it started up faster than before. It did seem very weak.

 

[superorange]

So I have a feeling it's the coil pack only cause I turned the boost down and droe te car tonight and same results. I won't have the pump in in the morning and we can go from there

 

[richard33]

Here is a log of the issue now. At 217sec is where the breakup is. He floored it but the TPS only reads 92%.

 

[Calan]

The TPS probably isn't adjusted. Also, voltage is still dropping off much more than it should be.

 

[richard33]

The TPS probably isn't adjusted. Also, voltage is still dropping off much more than it should be.

well I did the TPS adjust through link but that didn't work. I forgot to check the cable itself cause we got caught up in other things.

AS for the voltage issue. The stock wiring to the alternator is unhooked. He has one wire going from the alt to the fuse box which goes to the battery. It seems pretty ghetto but he bought the car like that. We put a walbro in the car which didn't fix the problem obviously. Also turned the boost all the way down. At this point I don't really know what could happen.

Everything was fine until he was break boosting for a little big longer than he probably should have been and then this happened.

 

[945liter]

That voltage is CRAP, does it break up at the same rpm every time? under WOT only or different loads?

 

[Chicken Patty]

I did the TPS voltage adjustment too and with the car off I forgot what voltage it read but it was at 0%, and then WOT was a perfect 100% and 5.00v.

Have you checked your plugs? Did you break boost after the new plugs or with the same plugs that you tuned the car with? I know you changed them just don't know if it started with the old or the new plugs.

As stupid as it may sound, but checking your plugs and re-gapping them might be worth doing and it's quick and simple.

 

[superorange]

I did the TPS voltage adjustment too and with the car off I forgot what voltage it read but it was at 0%, and then WOT was a perfect 100% and 5.00v.

Have you checked your plugs? Did you break boost after the new plugs or with the same plugs that you tuned the car with? I know you changed them just don't know if it started with the old or the new plugs.

As stupid as it may sound, but checking your plugs and re-gapping them might be worth doing and it's quick and simple.

Happened on the new plugs and I checked they are all still gapped the same

 

[Chicken Patty]

Happened on the new plugs and I checked they are all still gapped the same

What are they gapped at? ...and what plugs are they?

 

[superorange]

That voltage is CRAP, does it break up at the same rpm every time? under WOT only or different loads?

At different loads not just wot. It won't go past where it broke up on the log.

 

[Calan]

As stupid as it may sound, but checking your plugs and re-gapping them might be worth doing and it's quick and simple.

His voltage is still dropping into the 11's. Plugs probably won't make a whole lot of difference.

FWIW, on a auto parts alt I am seeing a consistent 14.2 to 14.6 volts under normal conditions, dropping to 13.6 at WOT. Anything in the 11 volt range at WOT is probably way too low to maintain a consistent spark and injector pulse width.