94 TBI Hard Start, Doesn't Run Right??

[adb5274.ab]

94 Chevy k1500 5.7L 4x4

So been restoring this truck and has been sitting for 1 month, ran fine before I began working on it. Go to start it for the first time yesterday and after much struggle it would only start after pumping
the gas vigorously and after it started didn't run well at all although it would idle. after it idled for while i was filling it with new coolant i go to rev it up and it dies, will not even try to start without
pumping gas and even still would not start.
* I can hear the fuel pump running

Things i replaced:
-cap, rotor, plugs, wires (i checked the wires and all are landed in the right spot)
-oil pressure sensor
-PCV valve
-open air filter
-fuel filter
-fuel lines
-long tube headers (currently don't have the rest of the exhaust fabbed up yet but the O2 sensor is installed into the headers and plugged in

Also, i swapped out the auto trans for a 5spd, I've done this on newer trucks and had to splice together the "park position" wires (purple and yellow) to get it to start but i did not see these wires on this
truck

I havnt checked fuel pressure yet but my first suspicion is that something i replaced or swapped is the culprit do to the truck running fine before i started tearing it apart. Seems like an electrical/ecu issue
because when it seemed to run very rich, lots of white smoke in the garage

Any ideas???? thanks!

 

[someotherguy]

White smoke isn't running rich. Rich is black smoke. If it SMELLS rich, keep in mind without a catalytic converter you'll smell the exhaust more - but if it seems inordinately rich then your CTS is probably bad or the sensor grounds at the front of the intake have a bad connection.

When it stalls out does the idle speed fall off and right before stalling makes a big sucking sound (IAC going wide open)? If you pull a couple plugs right away, are they wet with fuel? Then that's running...really rich.

Richard

 

[adb5274.ab]

I actually cleaned up the grounds from the pass side frame to the firewall and the ground bolted to the thermostat spout. Any other grounds I looked past?? and the CTS being bad would make it that difficult to start even when cold?? if so this may make sense because I did not have a temp reading yet even after idling for 10ish minutes in 80F weather. It did surge a bit before it stalled out completely as well, is there a way to test the IAC sensor? Im also suspicious of the ESC just because it seems to act as if its way outa time?

 

[adb5274.ab]

Also, the truck came with a new pickup coil in the glove box, asked the guy I bought it from why it was there and he didn't know, said it was is there when he bought it. What are the symptoms of a bad pickup coil??

 

[adb5274.ab]

would the lack of back pressure from running open headers make it run so horribly??

 

[someotherguy]

Bad CTS can cause problems under all operating temperatures depending on how bad it is. Keep in mind the CTS has zip to do with your dash temp gauge. That's handled by a separate sender, on the driver's side cylinder head.

The IAC isn't a sensor; it's a stepper motor with a pintle that seals against an air inlet into the throttle body.

Very generally speaking, a bad pickup coil would be - no start/run at all.

One thing I forgot to mention for a rich scenario: be sure the vacuum line for the MAP sensor is firmly connected, not leaking; this is a plastic line with a rubber boot on it where it connects at the rear of the TBI. If it's loose you'll run rich.

Richard

 

[adb5274.ab]

ok cool, ill ohm out the CTS and see what I get, just looked up ohm vs temp ratings for the CTS and at about 70F I should read around 3520 ohms. Ill also check the vac line to the map, very possible I knocked it loose or broke it while messing under the hood. As far as the IAC, these can be cleaned correct? should the battery be disconnected and reconnected to re learn its position? Thanks for all the help by the way

 

[adb5274.ab]

Just a quick update, I really think the lack of exhaust/ back pressure was the problem. CTS ohmed out correctly, bolted up the first couple feet of my exhaust and def made a big difference. It doesn't run great but atleast starts and runs enough to move it in and out the garage. hoping once I get the truck painted and can then fab the rest of the exhaust up it will run normally, thinking I may need to run a crossover pipe in the duals behind the tcase tho. thanks for the help