5.7L TBI - No Fuel? Injectors? Pressure? - Third Generation F-Body Message Boards

DDawg16 · 07-28-2009, 12:11 AM

Hi gents....great site...gave me a ton of info as I was doing my SBC swap into my jeep.....and I have tried serching and came across a few possibilities...but nothing exact.

Here is what I have the the problem I am having....

5.7L TBI out of a 93 Chevy P/U installed into an 84 CJ7. Everything is wired up as it was in the truck. I kept the 4L60E tranny...I have the right VSS and sensor.
Carter external fuel pump for the TBI
Return line is 1/4" stainless...might be a slight issue
The O2 Sensor is a Bosch...3 wire IIRC....it's about 20" from the left exahaust manifold....
The exhaust manifolds are 2 1/2" Ram Heads....because it's a jeep, the stock manifold would not fit...the right side crosses under the oil pan and joins up with the left side into a common y tube and this is where the O2 sensor is.
The engine runs fine though it does feel like it's not running quite as good as it should...
Gas mileage is not what I expected....averaging around 12-13 mpg....and that is taking it easy....
I barely pass smog....CO and NO are great...HC is right at the limit....

I have a OBI scanner....everything looks fine....temp is correct (193 deg tstat)...engine goes into closed loop just like it should....O2 sensor reading does it's cross over as it should....

Timing is at spec....0 deg.

I get an occasional miss while setting at idle.....

This morning the jeep quit....it was sluggish....then started acting like it was out of gas and then quit. I can hear the fuel pump when I turn on the ign....

I pulled the air cleaner...wiggled the injector wires and connectors...tried it again...cranked right up. No delay. If I had a fuel pump issue I would have expected a delay for pressure to build up.

I don't have a press gauge installed....but I am looking at getting one...

I looked at my schematic....I have a fused 12v ign going to both injectors...and the other side of the inj go to the computer....if one was not making a good connection I would expect the other to keep the engine somewhat running....

This happened once before a few weeks ago while my jeep was at a buddies shop getting some metal work done....one day she started and then cut out the same way it did this morning....would not restart....I went over and confirmed the issue was fuel....we could squirt in carb cleaner and she would start...had it towed home...tried it in the driveway...started right up...

I hate intermittent problems.....

Ideas????????????????

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