stumbling idle??
Here's my problem. I had a problem a while back where my car just started stubling and then die while driving down the road. I would turn the key to restart and off I went. It done this several times for about 10 miles. I finaly pulled over. Shut the car off and restarted it ran fine for 5 months.

Now I just put a supercharger on and now the surging problem is back. THe car will surge only after a quick tap on the gas and stumble until I let off the gas and then die. Just turn the key and running fine again and this keeps happening with every tap on the gas. If the car is in park nothing, revs fine and never a stumble. If I take it easy car also runs fine. If I keep it floored runs great until I let off gas.
I don't think it's the supercharger due to this all seams like my problem I had a while back.

 

Ive got a similar issue since turboing my car. Ive put it down to either;

- exhaust leak ( i can hear a slight tick)
- not being intercooled and inlet temp being too high
- needing more/less fuel pressure. (does a surge/stutter usually mean too much or not enough fuel?)

 

To me it sounds like a weak pump or not enough fuel. Hook up a gauge and check your pressure. If the pump was going bad, now it will get worst with the boost. Do you have a fuel pressure regulator? Is it boost referced? Are you carb or F.I.? Are you using a FMU? Need a little more info.

 

I had the same problem and it was my pump. I hooked up a gauge and Left the hood open and did a burn out while my brother looked at my fuel pressure from the side of the car. It turned out to be the stock TBI pump was not able to increase more than 12lbs with my 11lbs of boost. Remeber, if you are carbed with a hat you must increase your fuel pressure 1 lb above the 8 psi it already gets for every pound of boost. Now I have a GN gnx pump in there and at boost my fuel pressure rises to about 20 lbs or so and it runs awesome. If you only feed the carb 8psi of fuel and boost 10psi, it will push the gas back to the tank.
Even if your fuel injection, buddy to me it sounds like its starving for fuel. Hope that helps you guys..

 

The car is TPI and has a fuel pressure regulator. I put the extra fuel pump that came with the set up on and the FMU also.
How do I figure out if it is boost related. Can I just take the bely off or do I need to do something else.

I will check the fuel pressure tonight.

 

Alright here is where I am at.
The fuel pressure is at 50 and when floored it bounces around quickly at 45 to 60, seems real good to me.

What I have noticed it that the boost retard control when turned up past one on the dial seems to make this problem worse. The lower I put the dial the less the problem but when I get the dial under 1 1/4 the car pings and tings so I can't turn the dial down. So now what should I do??

Comments PLEASE>

 

I think you have a timing problem. Check your initial timing on the distributor with a timing light. Before I had the BTM, I would retard and lock my timing too back and my car would do a stuble and a lot of popping in the exhaust. It was my timing. I was pulling too much timing.
Check your timing. Set the initial retard on the BTM box to start boost retard at 3 lbs. Its the little **** on the box itself. Play with timing. Its your timing.

Any questions, just reply

 

Thanks, you nailed it. I just went from 10* to 8* on the timing and all is well.

Thanks for the help.

 

No problem man. I am glad to see it worked out.