Well after three hardcore days of installing a new 350 within the 1984, I have come across an issue here that is unsolvable, setting the timing to 6 to 8 degrees above TDC I hook up the wires again to the computer and then the computer raises the timing up there even more above 12+...

Well here's the scoop of all new:

Engine
MAP Sensor
All block sensors (Water, Oil and etc..)

Then I go and look at the fuel coming out it comes out evenly and therefore have my neighbor rev it up some, here's what I see:

Front TBI is clearer than the rear TBI gas flow... (Meaning that the mist is very clear on the Front TBI)

Now as being in "Park" there is no stuttering or chugging at all. However when taking it out on the road for a test I get the stuttering and chugging effect of like it's starving for fuel.

So anyone have run across this issue or possibly know of what this may be...

History: I had the injectors flushed off a machine when the old engine was in also where they did it while the engine was running hooked up to the fuel filter.

Hate to: Spend another $500 for injectors...

So any of you 1984 Gurus know of what can be the remedy please shed some light this way. Any help is greatly appreciated and surely in need before I get more grey hairs...

All the best!!!

 

One way to check injectors is use your timing light. The pulse rate on your light should equal the pulse rate of the injetors and you can watch the spray pattern a little better. Another way is to perform an injector bakance test, but if you do not have a tester to pulse injectors then that is impossible to do. Injector balance test consists of hooking up to fuel test port with a pressure gauge, then unplug injectors, hook the test to each one individually, then turn key on to energize fuel rail, then activate tester and measure pressure drop on each injector. They should be within a 1/2 lb of each other. Drop rate depends on how many pulses the tester pulses the injectors. The less it drops, the leaner it is and without experience in watching them (there are only 2), it may be hard to determine which one is bad. Delco makes those injectors for around $80.00 apiece, plus a gasket kit for each throttle body (I think the gasket may come with the injector). Good Luck. [8D]

 

Also, do you have access to any scan tool readings, such as Block Learn? MAP voltage and vacuum?

 

When you say "hook up the wires again to the computer", which "wires" are you referring to? There is a set timing connector, wire color is tan with a black stripe that needs to be disconnected to set timing. Should break out of the wire loom somewhere around the distributor.

BTW, I replied to your e-mail and it won't let it in you system, because I am not on your list of "contacts".

 

I'll be taking your awesome advice and will try everything you recommended and update you on this here. Let me say WOW also on your replies!!!

I have never had this issue after dropping in the 502 in the 77 (C3), bolted it up and off I went, now on this C4 is going to be the fun one it seems.

All the best!

 

No, but it seems I need to order some scan tools now getting into this more computerized world of vettes... Any recommendations of where and what tools to obtain?

 

Holy cow, guess I need to hit up NAPA? Cause I went to Carquest and the injectors they carry are $250/apiece also, finding that on the C4 Crossfire they are two different part numbers / types as well (very odd if you ask me )...

 

That's the wire with a PAC connector too it that I disconnect before setting the timing... As I said, once I get ready to hook it up again, the computer takes it up to 10 degrees higher on the timing... This seems to be the issue here I'm thinking, even I set it to 6 degrees under TDC to see if it sets the timing to 6 degrees above TDC and it does, however then it seems to be bogging down when you throttle up.

All of this worked fine before swapping out engines and rehooking it all up. What a nightmare but soon to see it through

You were added to the allow list due to the damn viagra emails that have been influxed in the last two weeks!!!

 

When you plug the set timing connector back in, it is supposed to raise timing up 10 to 15 degrees. What you are doing by disconnecting it is putting it in base timing, like unplugging vacuum advance on older cars. Need to watch the timing light when you throttle engine see if you getting around 20 to 25 degrees of total advance. Also, scantool costs are prohibitive if you are not in the business of using them. Most start around $1500.00 bare bones and go up from there. I have 3 or 4 at my shop and the last one, Mastertech, was (choke) $8100.00. Besides, if you don't know how to interpret the data, you would be wasteing your money. [8D]

 

Okay, got the scanner and plugged it in and got the normal code of 12 then I got the code 42 afterwards..

So this is narrowed down to it being something in the Electronic Spark Timing circuit... So, any ideas what could be causing this, as the ignition module is brand new, new cap, new rotor, new wires and etc.. The wiring looks fine visually at the connectors at the distributor where it connects into the 4 pin connector. So this is leading me to the Electronic Spark Control or Knock Sensor or the wrong wire hooked up to the Knock Sensor?

Any ideas on this error code 42?

You have been a great help so far!!!

All the best!!!