1993 350 - Rich and Retarded

[quadhauler]

 

That pretty much covers it. This thing is rich at idle... it'll just about make your eyes water and at low to medium acceleration, it just doesn't respond like it should. I've replaced everything, but the distributor and IAC valve and it still does both things. I even swapped motors, due to bad head gaskets and it being a 305 and still the same thing. As far as the timing, when the air cleaner is off, and you give the gas, even without load, you can hear the timing being retarded thru the throttle body. When I disconnect the distributor, it actually sounds better since the timing is static. Is there something in the distributor that controls timing that could be bad? I've got no codes and it runs good, other than what I have desribed. Its an extended cab and still gets mileage in the 17's. Thanks!

[asepgrad98]

Rich and Retarded

 

Since when did we start making threads about John Kerry

[quadhauler]

There's one in every forum...

That was a good one!

 

But, that doesn't help my problem... however, at least it will keep the thread bumped!

[mark w]

sounds like my mother-in-law

 

minus the rich part

[citydriver]

Is the base timing correct?..If I remember correctly it should be 0 deg TDC w/the est connector(brown wire w/white stripe)disconnected...Have you checked for vacuum leaks?...should be a TBI...do you have a leaking/bad injector?...could be a bad MAP sensor,or maybe even a bad O2 sensor.....Check to see if the PCV is operating correctly and the vacuum line isnt plugged......just a few starting points

[MN Z-71]

Rich and Retarded

 

Since when did we start making threads about John Kerry

I was thinking Bush.

[quadhauler]

I've got the base timing set at about 2 degrees advanced. Any less than that and it runs even worse. I've rebuilt the TBI, with new injectors (twice) once with the 305 and changed the injectors to 350's. New knock sensor when the 350 was installed. TPS is new (delco), MAP is new (napa), and always the same results. All vaccuum lines were new/inspected when the 350 was installed and the PCV area under the TBI was cleaned out too, as it was severly clogged when I get the truck, back when it had a 305. It really ran bad when I got it... Cat is gone, thinking it was clogged. Fuel pump is new and fuel pressure is good. I've just about decided to put in the edelbrock port injection, but I know the TBI will work well if I can get thru this. I do everything myself, but I'm about ready to get a dealer mechanic to run diagnostics. Geez, I wish this thing was OBDII! I'd buy a reader, since it would work on my other cars and be done with it. Thanks for any input you guys can give me..... Its kinda funny, we've got some 4.3's here at work (WT1500's) and some of them do the exact same thing on the slight acceleration/uphills. They actually bog when slight acceleration is needed and then you have to floor it and it kicks down and revs to the moon!

[Butch 02 Denali]

When you changed to the 350, did you change the computer too, or at least the chip?

If not I'd start there. But if it was running crappy with the 305, and you still have the same computer in there, I'd say you have a corrupted program or a bad computer. Get another from a junkyard from a 93 with a 350 and plug it in, probably about $50, less than it would cost for the diagnostics.

 

Butch 02 Sierra Denali

[quadhauler]

Thanks for the info Butch. I bought the 350 chip when I bought the motor... hoping the problem wouldn't follow it. I was surprised, it would make my tranny shift really badly. The 1-2 shift would be like this: 1st gear....... I think I'll change now.... 2nd g.... no back to 1st.... then a slide shift or a BANG to 2nd! Depending on throttle pressure. That was when I changed the TPS. It still did the exact same thing with the 350 chip (original post problem)... except the shifting thing. I went back to the old chip and the shifting was good again. If I pay someone to run diagnostics, a GM mechanic, will he be able to tell if the computer is bad even without codes?

[Butch 02 Denali]

That's it!!! The 305 chip has the wrong fuel program for the injectors for a 350. What year was the 350 chip from, and does it match the 4 diget code on the computer? The shift program must match or it will do crazy things like yours is. There are a few different codes, I remember AJRT or something like that for my 1992. You know it would probably be almost as cheap as allot of diagnostics, and certainly better in performance to just get a custom chip from Wester's.

 

Butch 02 Sierra Denali

[quadhauler]

I hope you're right. When I bought the motor from Pace the guy took quite some time while he crossreferenced my truck... if it came with a 350. Of course, you could be right, he may have gotten the wrong chip.. You see, while he was on the phone, I asked him what ratio my truck came with. He said it came with a 3.42... he was wrong, I've got a 3.08.

 

I suppose Westers is on the web? I haven't heard of them before. Thanks again.