Installing 2.0L FI Components on 1.7L Engine?, Alternative to switching to carbs Options

[ThinAir]

My son, Mike, has a 1.7L with FI that has lots of problems with the FI wiring harness. He was going to switch to carbs just so he could get it running again, but he remembered that he has a complete 2.0L FI setup available. He's thinking of putting everything from the 2.0L FI onto the 1.7 except the injectors and throttle body/TPS.

I've seen several threads that make it sound like the 2.0L FI wiring harness will work with the 1.7L injectors. Using the 1.7L injectors should ensure that the flow rate matches the engine. Any reason why the rest of the plan won't work?

[JeffBowlsby]

It depends on which 2.0L harness you use. The 73-74 FI set-up is different that the 1975-76 setup. Intermixing sensors, injectors and other parts spells trouble.

If you mount the 2.0L harness using the 1.7L air plenum, the 2.0L harness fits sort of, this from a trustworthy source:

"I tested fitted the harness tonight. Everything fits except for the TS1 wire, as shown in the photo. The TPS lies directly under the throttle body (where the big black elbow connects to). Because the TPS is so far towards cyl 1 and 2, the TS1 wire is too short to reach the TS1 sensor, which is located on the airbox directly opposite the throttle body. (Lower left of the 2nd image.) To resolve this, I propose leaving the TS2 length about the same, but branching it off separately from the TPS wire. The wire will leave the harness a little “late” (past the sensor and loop back) but it should fit. Moving the main TPS/TS2 branch to towards the ECU about 4 inches would help even more."

If you transplant the entire 2.0L system, incl the airbox, throttle body, you'll get too much air into the engine. and you need to modify the intake runner mounts and the TPS connector, maybe more.

Why not just correctly fix your 1.7L set-up - get a new 1.7L harness? (IMG:style_emoticons/default/wink.gif)

[Dave_Darling]

HINT: Look at the sig of the post immediately above mine. Those harnesses are better than new...

--DD

[ThinAir]

I'm quite aware of Jeff's harnesses. I've replaced all the harnesses on my 73 with Jeff's and highly recommend them.

In this case, Mike is looking for a temporary setup using the stuff he already has. The 1.7L will be going away once the 2.0L engine is ready and he doesn't want to invest in one of Jeff's 1.7L harnesses for an engine that he won't be using for very long. It's too short of a time to make that kind of investment, but too long of a time to just wait on finishing the 2.0L engine.

Jeff - the 2.0L FI is a 1973.

[SLITS]

Ernie ... I will look tomorrow and see if I have a good 1.7 harness for Mike.