Idles then dies when SPOUT is in

[Distortion 5.0]

have you checked the MAF sensor??

a sensor reading is probably bad, the car seems to run fine in open loop but runs bad in closed loop.

Hmm. Ususally when I have MAF problems Idle is the only thing is does worth a damn.

I get the feeling from all this that maybe this is a not so common problem causing a fairly common syptom.

I'm trying to think to myself "what all is happening when that idle drops?"

The IAC motor moves,
timing is adjusted,
manifold pressure rises moderately, (but this car is barometer anyway)

If the 02's were bad then the problem would be more persistant most likely.

It really seems like the most likey source of the problem is either a vaccuum leak, or a problematic ECM.

The FPR could be stuck open, but my instincts doubt it.




Get a can or two of some o2 safe TB cleaner;
First clean out the intake really really good, be careful with your MAF,
but you want that clean as well. (I do it with the TB cleaner, I dont think that is really reccomended)
Then, twist your idle screw up so it will stay running, and spray the cleaner at all the different vaccuum junctions around the engine.

If the idle is affected when you spray a certain area, then you have found a vaccuum leak.

I hope some of this is useful. Those 2.3's can be your best friend or your worst enemy.

That's why I love my 5.0 T-bird. So far it hasn't thrown me a single problem I couldn't figure out.

I never fully understood my mustangs attitude.

Good Luck!

 

[btroppmann]

Distortion/cjones:-

Its an 89, so there's no MAF.

Yes it seems to run fine in open loop but crappy in closed loop. Car seems to run lean based on reading the plugs. All the plugs have a whiteish tan appearance, and all the plugs look the same (I think ruling out a clogged injector).

I check fuel pressure at idle its 32 psi. Is that low? maybe the injectors are delivering less gas than the ECU expects because of low fuel pressure. Fuel filter and fuel pump are new.

RE vacuum leak: I went over all the tb connections and vacuum lines with an unlit butane torch, no rpm changes, everything is tight.
RE TB: I cleaned it out and replaced IAC.

Bob

 

[cjones]

fuel pressure should be 35-45 KOEO and 30-40 KOER with FPR vacuum hose disconnected

 

[btroppmann]

Fuel pressure is 38 psi KOEO and 34 psi at idle

 

[btroppmann]

Success!!

Ok I finally got it working....
I was going through the timing again, camshaft, tdc on crankshaft, distributor rotor pointing to #1. I lined up the timing mark on the crankshaft and popped the cover for the inspection window on the timing belt cover to see if the camshaft marks also lined up. Guess what... they DIDN'T. I had a closer look at the cranshaft pulley and I found ANOTHER timing mark on the pulley, when I set that one to TDC the camshaft pointer were aligned. Just to be sure I pulled out spark plug #1 and used a thin piece of vinyl hose to confirm that piston 1 was at TDC when this timing mark was at TDC. Pulled the SPOUT out, set the base timing, and guess what.... the car idles perfect at 800 rpm.
The correct timing mark was about 25 to 30 degrees advanced from the mark I was using to set the timing, therefore my timing was super advanced and this caused my issues at idle (with no codes).
Thanks to everyone who helped me out with ideas on fixing this. Just one more thing - the two marks were machines in the pulley at the factory, they were identically cut. Does anyone know why there are two timing marks on the pulley?

Bob

 

[ethangsmith]

Must be an error. All 2.3L crank pulleys should only have one mark cut into them (unless it's an early 2.3L with the actual timing numbers cut into it and the pointer on the metal timing cover).