The motor I'm working on is a 1997 in a 2000 astro van. I'm familiar with the passenger side exhaust manifold having a return to the intake. This setup has the return line cut and crimped closed close to the exhaust manifold. I do not see any hole in the manifold for the exhaust return. It does have an egr valve.
Any help on this?

 

The fitting in the passenger side exhaust manifold is for the secondary air system, 97 is not equipped with secondary air.

There are several differences in the two engines with wire harnesses, PCM's, sensors, etc etc. The easiest way is to fix the 2000 engine, if that's not practical, you'll need to modify the vehicle so the 97 will work, (PCM, wire harnesses, sensors, etc etc from the 97). If it's not done properly, it won't run right, and you'll probably get a ton of DTC's in memory along with a check engine light.

Another thing that can make a difference with engine controls is the GVW of the Astro, (under or over 8600 pounds).

 

When I left this vehicle on Thursday it had all the lights on the dash when the key was turned on. It also had spark. Just no fuel pump.
Friday I went out in kinda drizzly conditions and removed the cover on the fuel pump relay and forced the relay closed. The pump ran so that is good. My pressure guage showed 60psi. Tried to crank but pressure not keeping up while cranking. I tried to put scan tool on but no communication. Found blown fuse in cab for cig. lighter and replaced with a good fuse. Friday lost all lights on dash but battery light and had no spark, no fuel pump. Still no communication with computer to scan tool. It appears all fuses are good using a test light.
I picked up another matching computer at the salvage yard just in case computer got damaged.
Really wish I had bought that Master Power Probe. I have a wire tracer but it sends out a weak signal. I have had success with it before so maybe I will have some luck using it here.
Just to let you know. When it was running prior to me thinking it was out of fuel, the only codes I got was for the temp sensor of which I replaced and cam/crank correlation. The problem really started when I replaced and plugged in the temp sensor.

 

Cam/crank correlation, (P1345), sets when the distributor is off one tooth or more in either direction. It will not affect ignition timing, but it will cause serious crossfire inside the distributor cap. If it's off too far, it can cause a no-start condition.

Fuel pressure: key on, engine off, fuel pump running, pressure must be 60psi to 66psi and it must remain above 55psi for at least 10 minutes after the pump shuts off.

You need to find & repair the blown fuse situation.

After replacing the PCM, the crankshaft position sensor relearn MUST be performed. If not, the PCM will use the data from the donor vehicle, which is incorrect for this vehicle, (relearn data is unique to each vehicle).

Might want to ask questions here first, you're digging yourself a deeper hole

 

Sorry the owner was saying it was a 97 but obviously it is a second gen motor. Yes, I was wrong in stating the pipe was on the passenger side. I asked the original question because I know the second Gen has a exhaust return pipe to the front of the intake. The pipe is crimped over on the manifold and the opening on the intake is wide open. Here is the missing pipe.
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As for the other condition of losing communication with ecm,ignition fire and lights on the dash.Today I figured out the what I am calling the ecm which is the computer in the engine bay is not getting proper ground
What I did today was run a wire with alligator clips to the computer housing and ground it to the chassis. I got back the lights on the dash, ignition fire and communication to the ecm. I also removed a wire from the starter.
It still cranks and will run for a few seconds but my guess is the missing exhaust return line is a major problem.
I'll take another look at the distributor.

 

1995 and newer S/T series, (Blazer Jimmy, Bravada, & pick ups) are all second generation.

From 1995 through 2005 there were ongoing changes to the 4.3L computer controls and injection systems on 2nd gen S/T series vehicles, no two years are exactly alike.
1995 through 2002 were "W" engines. 1995 is all by itself, 3 different computer controls and 2 different injection systems. 96 & 97 are very similar to each other. 1998 is all alone. 1999 through 2002 are similar to each other. 2003 through 2005 are "X" engines and are very similar to each other.

2nd gen S/T series 4.3L "W" engines have EGR valves, "X" engines do not.

1996 through 2001 L/M series, (Astro/Safari) are "W" engines and they are very similar to the 1998 S/T series "W" engines.

Under certain driving conditions when the engine is off idle, the EGR valve opens and exhaust is injected, (via the tube) into the intake manifold. The (now open) fitting on your intake manifold goes directly to the EGR valve inlet. When the valve is closed, there should not be any vacuum present at the fitting. When the EGR valve opens, it opens a passage from atmosphere to the intake plenum, and there will be a serious vacuum leak at the fitting. The kinked off tube on the exhaust manifold is an attempt to stop the exhaust from leaking. Without EGR, combustion temperatures will be excessive which will cause spark knock, which in turn will cause the valves and pistons to burn/melt.

If the engine starts & stalls, there might be a problem with the Passlock system or a fuel delivery problem. You'll need to check fuel pressure to determine if it stalls and looses fuel pressure, or looses fuel pressure and then stalls.

 

Thanks very much Captain! The information will be saved for future use.

Today started with no power at all. I removed the battery and put on charger. After installing the exhaust return pipe the battery went back in. It still had a no start condition. I took another look at the ignition timing. It was close but maybe not dead on so I went with it. It still would not run. Pissed most of the day chasing a gremlin. At times there would be communication with the computer and other times not. Same with the lights on the cluster and the fuel pump. To make a long story short at the end of the day I thought maybe I put the bad computer back in as I did not mark the one from the salvage yard as I should have. Swap. Bada Bing! and it came to life.
I'm doing my best with what I know and you're input has kept me at it.. I am working on this one after two other guys tried. I found a missing bell housing bolt being used to attach the exhaust manifold. So far I had to install both dipstick tubes, swap the exhaust gaskets around to stop the exhaust leak, stop the leak from the timing cover, install a exhaust return pipe of which there was none and don't let me forget all the miscellaneous screws and bolts I got from the salvage yard just to put many things back in place. Still a few miscellaneous bolts missing but another trip to the salvage yard will make things right.
Going back tomorrow to button it down. The owner said he paid for a new distributor but it is rusty under the rotor and the rotor is only held in place with one screw. He wants a new rotor, new wires and plugs. These things he already paid for but were never received.

 

Close to the thermostat housing there are a couple of ground wires for the ECM. There are eyelet terminals on the wires with a bolt securing them to the intake manifold. Make sure the wires are connected to the terminals, and the ground connection is clean and tight.

 

It turns out one of the two before me cut the eyelets off the wires you said needed to be grounded. What they did was add a second temp sensor below the thermostat housing using these wires. I think this explains why the computer had ground at times. Do ya think that was the gremlin?
It still threw the cam crank correlation code today until I replaced the rotor. With the new rotor (BDW product) it is throwing random misfire, bank 1 lean and the knock sensor circuit is high. The knock sensor is not connected as the connector does not match the sensor.

The balancer outer has spun so I'm not able to use that for setting timing. I am not especially confident in the distributor. It is an after market with aluminum contacts in the cap. The oil pump drive rod does not mesh with the distributor well when dropping in. The rod is leaning like the connector to the oil pump is worn. I must have tried setting the timing at least six times. I am going to bring another distributor with me tomorrow. I may bring a round file to elongate the lock down bolt hole. I have read some people on this site have tried this.
Don't know what to think about the bank 1 lean condition.

I may still have the shovel in my hand as you stated the relearn is necessary or old data will be used.

 

Temperature sensor resistance changes with engine temp which might explain the erratic behavior with the PCM ground. When people mess with vehicles, and don't have a clue what they're doing, anything is possible.

P1345 is set when camshaft retard is off ~26 degrees or more, in either direction. This is because the distributor gear is not meshed correctly with the camshaft gear. If camshaft retard is off more than ~2 or 3 degrees, it can cause the P0300 to set. If the balancer slipped, it makes it very difficult to install the distributor correctly. Best bet is pull #1 plug, stick a plastic drinking straw in the hole, and turn the crank clockwise with a socket & ratchet until the piston is at TDC, AND the rotor is within a few degrees of the "6" on the distributor housing. Then re-set the distributor so the rotor points to the "6". AC Delco distributor caps have aluminum terminals, (conducts electricity better than brass). Brass terminals on a distributor cap are a sign of cheap quality.