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I have a 94 astro with a 4.3 CSFI. I replaced the fuel pump and the egr valve. The motor runs great, all the electrics work, the speedo works, but it will not shift into higher gears. I have reverse, 1st and 2nd. What did I do to it? When I replaced the fuel pump I disconnected the battery, dropped the tank, replaced the pump and reassembled. It started right up and I drove it for about 20 minutes and it never shifted into 3rd or OD. I've driven it a couple of more times since with the same problem. I've checked all the connections and all the fuses but I cannot find a problem. Please help.

Submitted: 359 days and 8 hours ago.

Category: Chevy

Value: $15

Status: AWAITING CUSTOMER ACTION

Posted by diagman 359 days and 6 hours ago.

Info Request

did the problem occur before or after the repairs?

359 days and 6 hours ago.

Reply

the problem occurred only after the repairs. Also the fuel injection is actually throttle body.

Posted by diagman 359 days and 6 hours ago.

Answer

check the vehicle speed sensor on the transmission and see if it got damaged while working on the gas tank or unplugged also make sure the ground wire to the gas tank has a good ground.

359 days and 5 hours ago.

Reply

the ground connection checks out and the speed sensor looks good. The speedometer is electronic and it works fine.

Posted by diagman 358 days and 7 hours ago.

Answer

you will need to scan vehicle and check for any trouble codes and let me know what you come up with for the codes. DOES THIS MODEL HAVE A DETENT CABLE OR ELCTRONIC SHIFT (IS THE 8TH DIGIT OF THE VIN A W OR Z?)

358 days and 4 hours ago.

Reply

I had the van scanned at a dealership. It did not throw any trouble codes. The tech and I took a test drive and he was able to get the van to shift into 3rd and OD with the scan tool. He suggested that I replace the ECU. I did so and it did not solve the problem. The 8th digit of the VIN is a Z. I do not have a detent cable.

Answer

Test voltage back probed at the Powertrain Control Module (PCM) shift solenoids' control circuits during the problem. When the shift solenoid is commanded on the voltage should be under 0.5 volts. When the shift solenoid is commanded off there should be Battery Voltage (B+) on the shift solenoid wire at the PCM. If the command is correct on the scan tool but the voltage on the wires from the shift solenoid is not correct, remove shift control wires at PCM connector, manually control shifts by grounding and ungrounding the shift solenoids in the correct shift pattern. If the transmission shifts OK when grounding and ungrounding the wires at the PCM but doesn't work when grounded and ungrounded through the PCM, check the powers and grounds to the PCM and if OK replace the PCM. If the transmission will not shift correctly when the wires are grounded and ungrounded with the wires removed from the PCM, check the wires between the transmission and PCM for opens and/or shorts. If the wiring is OK check for an internal problem with the transmission

Expert:	diagman
Pos. Feedback:	95.8 %
Accepts:	261
Answered:	3/29/2009

ASE Certified Technician

17 YEAR MASTERTECH

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Info Request

did the problem occur before or after the repairs?

Reply

the problem occurred only after the repairs. Also the fuel injection is actually throttle body.

Answer

check the vehicle speed sensor on the transmission and see if it got damaged while working on the gas tank or unplugged also make sure the ground wire to the gas tank has a good ground.

Reply

the ground connection checks out and the speed sensor looks good. The speedometer is electronic and it works fine.

Answer

you will need to scan vehicle and check for any trouble codes and let me know what you come up with for the codes. DOES THIS MODEL HAVE A DETENT CABLE OR ELCTRONIC SHIFT (IS THE 8TH DIGIT OF THE VIN A W OR Z?)

Reply

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