Last Thursday my car started running like I picked up a bad tank of fuel. It began idling at 400-500 RPM like it had a miss or something. It stumbled when the accelerater was pressed.

Not wanting to hurt it, I had it towed to the shop. My mechanic said that he had several customers come through with bad tanks of gas and he would check it out. One fuel filter later, and the problem has not been solved.

The problem is definitely fuel delivery related. The car acts like it is starving for fuel.

It appears that the problem is intermittent. The only fuel mod that the car has is an Andial Fuel Enrichment System that was installed by the previous owner. At one point during his diagnostics, my mechanic unplugged the Andial System and the car ran fine. When I went to check up on it, he unplugged the system and the car still ran crappy. The only difference was when the system was pluggged in, the car would not rev up. When the system was unplugged, it still ran like hell, but the car would rev after some coaxing.

I am hoping that the problem is a bad switch or sensor somewhere. My mechanic is top notch, but admittedly does not have a whole lot of experience with working on 930s. I gave him my shop manuals and I know that he is tracking the problem down.

Any ideas here would be greatly appreciated. I miss my car!!!!

Cajun

 

I had a failing fuel pump at one time on my 911 that caused the same symptoms.

 

I've seen 930s stumble along on just one of the two fuel pumps much like you described. You might check to see that both pumps are running -- it could be as simple as one of the fuel pump relays.

 

Guys,

Thanks for the replies. I just got a call from my mechanic. He said that as soon as he removed the Andial Fuel System, the car began running like a champ...

Oh well, I guess it is time to call Andial..

Unfortunately, the system was installed by the P/O & I don't have any of the directions....

 

My PO had one installed so I got Andial to fax me some info. It helped a little but it still wasn't real clear.

 

I have a photcopy of the andial install/instructions that came with the history of my car, very confusing.
Don't have the unit, my car had a stock engine fitted from a breakers yard.

 

Just picked up the car...Runs like a champ!!!

I don't know what the deal is. I am going to give Andial a call & ask them to send the instructions over. I might reconnect the system when I install the K27 & upgraded intercooler I have sitting in my garage.

This also seems to have solved the problem I was having with the car dying under full boost in second gear...and now the car is not having issues with stalling...

This was a cheap fix...thank heavens...

 

If someone could fax me a couple of the doc I would REALLY appreciate it!

(312) 795-1494.

Thanks!

 

I do, email in the morning to remind me. I will fax it right over.

 

Correction gentleman, the problem is NOT fixed.

The car ran perfectly last night, and this morning. I jumped in it to go to lunch, and it began running like hell again.

It put me down across town.

I am out of answers...If ANYONE has any ideas, PLEASE HELP. My mechanic is at a loss right now...

 

Once again; I'd replace those two fuel pump relays. They're cheap, they fail, sometimes intermittently, and the symptoms are exactly what you first described. Even if they aren't the problem, then you at least have a spare or two for the glove compartment.

 

Does the problem show up AFTER the engine has gotten up to operating temperature? I had two 911's that had this problem after warming up. Both of them were the Auxilary Air Regulator. When that heating element in them starts to get flaky, you get all sorts of idling problems. Did the mechanic check the fuel pressures when he was in there diagnosing the problem?
Mechanically, the CIS systems are very sound, the electro-mechanical devices(heating elements/bi-metallic strips) in the WUR and AAR leave a lot to be desired.

Dave
'85 Factory Slant 930

 

Yes Werk-I, the car does it most often when it is at operating temp. It has NEVER run hot.

Now, though, it is starting to run bad even when it is cold, but when it reaches operating temp, it stalls out....

 

I'd buy some CIS gauges and check the system pressure. The problem when it's hot sounds like a fuel delivery problem possibly with the pumps.

 

125 Shifter,

Thanks for the suggestion man. I was unaware that as the car heated up, the fuel pumps could create a problem...

Cajun