Started car today ?'s

[One_live95]

Well i had timing nailed(getting a little better i guess), and she fired right up. I let the car go through the first heat cycle while burping the coolant system. Gauges are installed, exhaust is still a little loose, and some other tedious things before it goes to the shop for the gear install:banana:

Anyhow now for the questions.

Before these heads, i had it where it would idle halfway decent, now it will idle rock solid for around 7-8 minutes(timed it roughly), and then it is like it will surge up, have a really high idle for a minute. I unplugged the IAC motor, and it seemed to have no effect on whether it would do this or not. Can exhaust leak cause this? Can the JMS chip be off that much now that there are different heads on the car? I also seem to be having a fluctuation in my fuel pressure. (causes?) After the car shuts off the Fuel pressure gauge drops to around 18 psi instantly and holds that... It has a new 190LPH pump. i believe i have it installed correctly, i have a paxton fuel regulator on the car and a kirban waiting to go on? Could the paxton be causing the problem(is it boost referenced?) I will switch them this weekend,


I still haven't installed the MSD 6AL, so is it possible its the ignition. I am going to check the torque specs tomm., that will be the initial cool down check/retorque, i can change the FPR while the upper intake is off if anyone thinks that is the problem...


BTW>>>> sounds same at idle, but rev it :drool: I think i am gonna enjoy it(although i haven't driven it yet) :nono:



jason

[coupe]

Something is happening after 7-8 minutes...maybe the coolant temp reference? Thermostat opening? ( :think: ) Also, check the basics like clean MAF element, timing set good...check the timing on the balancer when the idle goes high...it might be advancing. Also double check TPS setting. Just some shots in the dark. :nice: good luck.

[One_live95]

well one thing i realized after it was too late is that i put a stock thermostat in there, and the chip turns the fan on and the settings in the chip are for a 180 thermostat.... will that cause problems.... already bought a 180 but haven't put it in yet......that'll be tomm.

I think the TPS on the sn95 cars is set&baselined by the EEC though so i am unsure on that one. But i will check it anyway.

Anymore ideeee's :shrug:

jason
jason

[natedawgg94]

did you change cams with the heads or did you already have a cam?

[Italian LX]

Before these heads, i had it where it would idle halfway decent, now it will idle rock solid for around 7-8 minutes(timed it roughly), and then it is like it will surge up, have a really high idle for a minute

If your exhaust leak is before the O2 sensors, then that could be your problem. The ECU can be seeing a false lean condition and over time, it will learn to add more fuel -- this would l likely be your surging.

Tighten up that exhaust. :slap:


I also seem to be having a fluctuation in my fuel pressure. (causes?) After the car shuts off the Fuel pressure gauge drops to around 18 psi instantly and holds that...

Do you have and electric or mechanical gauge?

Does it fluctuate while the car is idling, or is the drop at shut-down your only concern?

Drops in fuel pressure after the pump stops is not unusual. It usually just means that the check valve back to the tank is bad. If it drops to a certain pressure, the check valve is probably weak and will only hold up to that level. If this is your problem, there is no need to worry; the only reason to keep pressure on the line is to minimize the time the pump neds to prime when starting the car again. As long at it drops to a set pressure (or slowly returns to zero) then it should be enough to keep the lines filled.

[NightHawk756]

If your exhaust leak is before the O2 sensors, then that could be your problem. The ECU can be seeing a false lean condition and over time, it will learn to add more fuel -- this would l likely be your surging.

Tighten up that exhaust. :slap:




Do you have and electric or mechanical gauge?

Does it fluctuate while the car is idling, or is the drop at shut-down your only concern?

Drops in fuel pressure after the pump stops is not unusual. It usually just means that the check valve back to the tank is bad. If it drops to a certain pressure, the check valve is probably weak and will only hold up to that level. If this is your problem, there is no need to worry; the only reason to keep pressure on the line is to minimize the time the pump neds to prime when starting the car again. As long at it drops to a set pressure (or slowly returns to zero) then it should be enough to keep the lines filled.

:stupid:

I agree on both. That's exactly what I think it is on both problems. Unless of course, the pressure is dropping while it's running. Then we have a different problem.

[One_live95]

well there is a slight fluctuation between 25 and 30 psi (vacuum on) on the gauge. when it is running that is. I have a BBK rail mounted gauge. could the check valve in the pump still be faulty if the pump is new..... less than 5K for sure...prolly less than 2k miles


That sounds like a good start on the surging... Thanks for the help so far guys.....


Natedawg, i already had a b=-cam with 1.7's just haven't ordered to FTI cam yet.... It will be in the new motor though when these heads make it on there.


jason