1995-1999 yukon

[Bushwookie1]

Hello ladies and gents. Ok. I've obtained a 1995 chevy tahoe with a 5.7 and TBI. I already have a 1999 gmc yukon with a 5.7 SPI . Question is how hard would it be to swap the motor out of the Tahoe into the yukon until I get the yukon motor rebuilt?

 

[Eman85]

That would be more then it's worth. Obviously completely different FI system so fuel system won't work. Different heads so swapping intake won't work if you wanted to swap fuel injection. And "getting a motor rebuilt" is a real thing of the past. Buying a crate motor or a quality remanufactured motor would be money and time better spent.

 

[Hoesgottaeat2]

Welcome to the forum. What's the issue with the motor that you need to rebuild it?

 

[BlackBearPerf]

Welcome to the forum from Northern Idaho!

 

[Bushwookie1]

Welcome to the forum. What's the issue with the motor that you need to rebuild it?

The 99 is all original. Starts up, idles at 1000 rpm , revs up good but once you put it in gear and accelerate it starts popping and acting like it's starving. I've changed the spider injection and no different. All new 02 sensors, new mass air flow, new plugs, new wires, even new distributor. Only thing I haven't replaced is the original ECM.

 

[Hoesgottaeat2]

The 99 is all original. Starts up, idles at 1000 rpm , revs up good but once you put it in gear and accelerate it starts popping and acting like it's starving. I've changed the spider injection and no different. All new 02 sensors, new mass air flow, new plugs, new wires, even new distributor. Only thing I haven't replaced is the original ECM.

Is the CEL on?
Do you have access to any type of code scanner?
The idle air control valve and TPS can both have symptoms like you're describing if they are failing.
By no means am I saying these are definite solutions, but I'd rule them out if you haven't already.

 

[Eman85]

Does anyone own a compression tester beside me? Start at the very beginning, it's a very good place to start.

 

[03catburban]

Check cam offset needs to be +- 2 degress, being you have a new distributor, those are very picky

 

[Hoesgottaeat2]

Does anyone own a compression tester beside me? Start at the very beginning, it's a very good place to start.

I have a compression tester. But I'd rather use a scanner before I pull a plug. In fact, I use my scanner while driving sometimes.
Can you see the traffic ticket now? It reads "OBD2 scanning while driving" LOL.

 

[TollKeeper]

I thought dropping in a early 5.3/6.0 was easy on these.. Better engine, more power, and a few other things.

Can anyone offer input on that?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[strutaeng]

Definitely diagnose your engine properly before condemning it.

To answer your question, the late TBI should be able to be retrofitted into the later trucks, but you have to keep the Vortec heads, cam, lifters, the "spider" retainer that keeps the lifters and obviously all the electronics, sensors, intake, timing chain cover with the crank position sensor. Basically you have to just use the shortblock of the TBI.

The late TBI SBC had provisions for the roller cam of the Vortec SBC.

Check out YT channel called "my vintage iron". He's got a video on this. I think the TBI guys have swapped to the Vortec heads for more power, as the TBI heads really suffered from low airflow. Some machining allows to keep the TBI intake.

 

[Bentawrench0r2]

I thought dropping in a early 5.3/6.0 was easy on these.. Better engine, more power, and a few other things.

Can anyone offer input on that?

Can confirm earlier 5.3 into GMT400 replacing the 5.7 feels entirely better on right pedal to floor ratio... "dropping in" is a phrase tossed in there by the keyboard experts. I had a complete donor 5.3, w/ 4L60E from an '02 with harness & PCM, working nights and part time some weekends took about 7 weeks to thin out the 5.3 & 5.7 harness & integrate the two so factory gauges and AC would function. Spent a couple of weekends and some nights getting the motor & transmission into a '97 Suburban, another weekend reworking fuel lines & transmission lines, $800 bucks in ICT Billet brackets to relocate the alternator to the passenger side & AC compressor to driver side, just so I could reuse stock lines for AC and not have to custom make a set, then there was the belt measurement, power steering pulley debacle, the pulley didn't seat on the shaft all the way, off by one rib and shredded new belt on start up, ordered new PS pump & pulley, and new belt, rework the air intake tube trying to reuse the stock intake box, either too close to the exhaust or to high to close the hood, fabricated a box for the filter that mounts behind the bumper and tubes up & 90's into the throttle body... so the mechanical fan is no longer an option, trip to the pick n pull for some electrics, then another Amazon order for relays to control the fans, take the harness apart to re-pin back to the PCM for fans control... and the road goes on forever lol. The whole swap started in April, pulled into my shop with a busted radiator, 297k on the odometer, numerous oil leaks, and the 5.3 was sitting in the corner for another "project", hey why wait, let's use it for this one! Rolled out of the shop Labor Day weekend. Was definitely worth the effort, much more fun to drive, sounds great, also built new 3" duals for it, so will I do another one? Absolutely!

 

[Tonyrodz]

Just for the hell of it--check the plugs going into the pcm for any water or dirt intrusion.