Surge at 2k rev after afpr install

[silvercoupe97]

I have looked around for surging problems but most if not all were at idle.

Ok, I've just finished with my afpr install, no leaks and idles like a champ without any intermitten sputtering , the problem I now have is that if I press the gas pedal and allow the rpms to slowly climb to ~2k, the motor will surge about 500 rpms down then up again, etc... at a slow pace. If I press the pedal fast enough and pass 2k I can hold the rev at say...3k-4k without a problem. Again, this just started after install the afpr.


It has done this cold and warm. I've yet to put a load on the motor since it was late when I finished with the afpr. I have a 1G CAS (don't know if that helps), I don't know what other info will help...

*I do think my tb is a bit dirty because my tps shows 53% (or is it .53v?) on dsmlink if I slowly let off on the gas, but if I tap the gas it goes back to 49% (or .49v). I guess it could be the throttle cable too. Bah, I'll check it tomorrow.

TIA,
John

 

[oldman]

You have been here long enough to know the importance of filling out your profile along with mod list, more importantly, details in your post such as which afpr and what psi is it set at.

 

[silvercoupe97]

My mod list is filled out .
The afpr is an aeromotive afpr set at 43psi. I don't know if it would matter but, it's the IE Aeromotive kit.

 

[andymoraitis]

Have you set the fuel pressure with the vacuum line disconnected? If not, you'll be flowing more fuel than 43psi and that may be causing your issues.

Let us know,

Andy

 

[silvercoupe97]

Have you set the fuel pressure with the vacuum line disconnected? If not, you'll be flowing more fuel than 43psi and that may be causing your issues.

Let us know,

Andy

I did do that..and with the line connected and the gauge shows somewhere around 33psi. I primed the fuel system with dsmlink but I also set the base fuel pressure with it (not thinking). That might have something to do with the surge, idk though. I will set base fuel again with the car warmed and the line off once I get my butt out there to do it.

 

[oldman]

My mod list is filled out .

My bad, you must have not fill out your vehicle type so I assumed the profile wasn't filled out.

 

[silvercoupe97]

My bad, you must have not fill out your vehicle type so I assumed the profile wasn't filled out.

Bah, no problem oldman. I have a 97 Dodge Avenger body with GSX muscle so it doesn't show up under vehicle type . It does show up when you look at my profile though, but not at first glance.

 

[ADrewzki]

Did you by chance disconnect the battery at all while you were installing the AFPR? If you did, it could be the car is relearning. Reset your AFPR back to 43 psi and see if that fixes your problem like previously stated.

 

[silvercoupe97]

Did you by chance disconnect the battery at all while you were installing the AFPR? If you did, it could be the car is relearning. Reset your AFPR back to 43 psi and see if that fixes your problem like previously stated.

Yes I did and I ran it a bit today without surge. I also let it warm up and set the afpr to 42ish-43ish (hard to tell on that Marshal gauge). So, like you said, it was probably the ecu relearning.
Thanks for the help guys

 

[oldman]

TPS should be at about 10% at idle, have you tried re-adjusting it? Did you re-tune after the afpr? You were probably removing fuel at low and part throttle due to overrun, now that it's fixed, you are probably running lean.

 

[silvercoupe97]

I'll check my logs oldman, I haven't had a chance to completely retune yet. I'm hoping to get a chance to do it tomorrow. I do need to reset my global and deadtime with dsmlink to -38 and 450us though. I will update this post once I get a chance to do it for future referrence for others in the same boat.

 

[silvercoupe97]

Ok, well, I must have had a vacuum leak somewhere because it stopped after I changed out all my vacuum lines and remove the fuel soenoid from the equation (just the vacuum lines, it's still plugged in electronically). Thanks for the help guys...problem solved....at least one of them until I have another, .

 

[haze]

Okay, I have a question, im guessing it could be a boost leak of some sort, but it could also be ten hundred other things also, so i need help.
When in 2nd and 3rd gear, if i give it full throttle it spudders and seems like its not getting enough gas or something, doesnt follow through all the way through gear with full power. doesnt really do it in 1st gear though. sounds like it spits out the exhaust too. someone help.

 

[silvercoupe97]

Does it do it if you just rev it to the same rpm ranges or only with a load?

 

[haze]

usually when its in the lower rpm range and i give it full throttle it will do it bad. if i bring up to say 5k then step on it, it really doesnt do it that bad.

 

[silvercoupe97]

How long has it been doing it? What did you modify/played with last? Are you venting to atmosphere? Do you have fuel upgrades? Do you have a logger? Will it stutter if you hold the gas at any rpm for at least 5 seconds (or any amount of time...just trying to duplicate the problem)?

Btw, you need more detail in you vehicle profile. For example..what does full exhaust mean...does it mean you have a turbo back with 2.75" piping, does it have a cat. I'm not being a ***k, I'm just curious to know what your car has to make it have issues, since every car is different.

I would say to check for vacuum leaks since that is the easiest and cheapest thing to do. If you have an afpr, then I would suggest that you eliminate the possiblity of that fuel solenoid leaking air (you have at least one line that you can delete from the vacuum equation + the solenoid itself, but keep it electronically plugged in). Get new vacuum lines, they're not expensive to replace.




Btw, mods/admin...my spell checker doesn't work anymore (yes, I do use it )...it hasn't worked since the site came back up.

 

[oldman]

Btw, mods/admin...my spell checker doesn't work anymore (yes, I do use it )...it hasn't worked since the site came back up.

It's being worked on and should be back up soon, you seem to be doing just fine without it.