Firing order 1988 chevy 350 my kid changed wires on my truck and mest up

this link will help Firing Order 1988 4 3 V6 What Is the Firing Order for 1988 GMC https://www.autozone.com/repairguides/GM-Full-Size-Trucks-1988-1998-Repair-Information/FIRING-ORDERS/FIRING-ORDERS/_/P-0996b43f80c90ea0

1-8-4-3-6-5-7-2 Distributor rotates clockwise vehicle , #1 cyl is on left side of engine

Firing order. 18436572

Find number one and place the wires on it in firing order, in a clockwise circle

You didn't post your engine size so please pick the correct one:



3.8L (VIN B and 3) Engines Firing Order: 1-6-5-4-3-2 Distributorless Ignition System



3.8L (VIN C, 1, L and K) Engines Firing Order: 1-6-5-4-3-2 Distributorless Ignition System



Buick-built 231, 252 V6Engine firing order: 1-6-5-4-3-2Distributor rotation: Clockwise



Olds-built 260, 307, 350, 400, 403, 455 V8Pontiac-built 265, 301, 350, 400, 455 V8Engine Firing Order: 1-8-4-3-6-5-7-2Distributor rotation: Counter-clockwise



Buick-built 350 V8Firing order: 1-8-4-3-6-5-7-2Distributor rotation: Clockwise



Chevrolet-built 267, 305, 350 V8Firing Order: 1-8-4-3-6-5-7-2Distributor rotation: clockwise



Chevrolet-built 262Firing order: 1-6-5-4-3-2Distributor rotation: clockwise

88 vett 350 engine firing order.

1-8-4-3-6-5-7-2

Install wire's clock wise.

here it is

350 Chevy engine in what? 1990 Corvette? Who built it, did you?

Sounds as though you have plug wires wrong.
Firing order is 1-8-4-3-6-5-7-2

Distributor Ignition System:
Distributor rotates Clockwise. (Rotor)
Find Number 1 tower on distributor cap, go Clockwise with Firing Order.

Distributorless Ignition System:
VIEWING the engine from the Front of the car.

Spark plug wire connections along the back, starting from Left side going to Right side;
2-3-7-4

Spark plug wire connection towards the Front of the engine;
6-1-5-8

(To guess I would say you have 5 and 7 wires switched)

Left side cylinder order is 1-3-5-7, going from front to back.
Drivers side is Left side.
Right side cylinder order is 2-4-6-8, going from front to back.

If your timing is good, dubble check your spark plug wire. Make sure they have the right fireing order.  
Good luck and hope this helps

18436572

the fireing order is 1-6-5-4-3-2