Q: Lexus IS300 won't start after transmission and engine swap

asked by on January 30, 2017

i did a auto to manual swap changed the wiring harness inside and out including the ecu etc and i threw the manual motor/transmission onto my vehicle but only my lights and electronics work. car won't even attempt to start or sputter or anything. what can cause my car to not start? i changed all my fluids, and belts as well. i made sure i didn't mess with timing on the timing belt and kept it to how it basically was (which was properly timed)

My car has 158490 miles.
My car has a manual transmission.

Car is not starting Inspection $94.99 - $114.99 Get a Quote

There are countless reasons your engine might not run after a swap like this. One thing to keep in mind, however, is that an engine needs three things to run: spark, fuel and compression. Checking for each systematically will help narrow down the potential causes for your concern. Spark can be checked with an inline spark tester. Fuel pump operation can be checked with a fuel pressure tester and fuel injector control can be checked using a noid light. Finally, compression can be checked using a compressor tester and/or a leak down tester. Diagnosing your vehicle’s no-start condition could be very difficult and time consuming. If you’d rather have a professional tackle the job, keep in mind YourMechanic comes to your home or office. We would be happy to diagnose and repair your no start condition.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I unauthorize a key fob that I lost?
Each of your key fobs is programmed specifically to work with your car. No other key fob will work with your vehicle. If you lose your key fob, or fear that it may be stolen, you want to unauthorized it,...
Car starts but then stalls
Since this issue did not present itself until after the replacement of the ignition switch, it most likely was created during the installation or reassembly process. In order to replace the ignition switch, the steering column needs to be lowered....
Overheating issue
The problem may not be a leak, but a malfunctioning water pump assembly (https://www.yourmechanic.com/services/water-pump-replacement) or faulty thermostat (https://www.yourmechanic.com/services/thermostat-replacement). Make sure the drive belt is properly routed and has good tension. If the coolant isn't flowing properly, the coolant in the...
Car won't start just one click when key is turned.
The first question you should ask, is why the terminals were melting in the first place. This is a sign something is wrong and this issue needs to be corrected, or the new battery may meet a similar fate. It...
Can a poorly installed wheel bearing cause extensive damage when driven on?
Hi there: It's highly unlikely that the installation of a wheel bearing causes mechanical damage that the mechanic has listed above. Typically those components (Axle shaft leaking, steering knuckle, lower ball joint, lower control arm, front strut) are not touched...
Can you raise the electronic speed shutdown point?
Hi there. You would have to either reprogram your computer to accommodate for the speed change or change out the speed sensor in the transmission to confuse the computer to allow the vehicle to go faster than the speed limiter....
Power windows and blinkers don't work.
Hi there. The relay to the windows could have stopped working. Also, the flasher or relay could have stopped working as well. Since these are two different electrical circuits, it could be possible that both relays quit, but more an...
My radiator blew and I overheated the engine. I can make it start but it won't keep running
Hi Brandon. Thanks for contacting us today. When an engine overheats to the point that the radiator breaks, it often creates additional damage to engine internal components and electrical harnesses that power many fuel and ignition systems. Without completing an...
I have a 2005 Volkswagen Jetta the engine just went is it worth fixing or trashing it
If your goal is to minimize the cost of transportation, compare the total cost of getting your car fully functional, in your case that would be the cost of repairing the engine, to the total cost of replacing the car....

Related articles

How a Clutch Engages and Disengages
In In your car transmission, the clutch is a device that works to engage and disengage the moving parts of your drive shaft. For purposes of this discussion, we’ll focus on manual transmissions. The moving parts are the transmission input...
The Best Used Cars to Buy If You’re a Photographer
If If you are a photographer, and you’re considering buying a used car, the big thing to consider is the type of photography you do. Thanks to the advances in digital photography, chances are you’re not hauling around a lot...
Understanding the Lexus Oil Life Monitor Service Indicator Lights
Car symbols, or dashboard lights, are a car service reminder. The Lexus Oil Life Monitor (OLM) indicates when and what service your car needs.