Quick Field Tests for Fuel Injector Troubles and Misfire Codes

[Moses Ludel]

As cost-conscious DIY troubleshooters, forum members talk a lot about testing ignition spark.  Fuel injector issues and injector misfire codes are also common.  For spark, there are surface probes like the Waekon 76562 COP ignition tester that we've discussed.  Waekon makes a similar 76462 fuel injector surface probe tester:  http://www.amazon.com/gp/product/B0021V0FRE?redirect=true&ref_=pe_58340_166621340_em_1p_1_ti.  

I have both tools, and they are quick and handy for off-road troubleshooting in the backwoods.  Whether you travel with a 4x4 group or alone, carrying these two tools in your off-road survival kit makes sense!  You'll be able to troubleshooting at the campsite or along the trail.

There is also the OTC 3398 Fuel Injection Pulse Tester that looks very smart and reasonably priced if you do any amount of EFI/MPI work.  We frequently discuss MIL/Check Engine lights and misfire codes for #1 cylinder and other injectors on the Jeep 4.0L engines, and this is one way to rapidly determine whether the injector(s) are really at fault.  Often, the Jeep 4.0L #1 Misfire code does not represent a bad #1 injector, but the owner or shop tech rushes out to buy a new injector or even a set of injectors that will not cure the actual problem.  (See topics covering this issue at our Jeep YJ/TJ Wrangler forum.)  I found this listing for the OTC pulse tester tool at:  http://www.amazon.com/gp/product/B0002SR5OO/ref=s9_simh_gw_g263_i2_r?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-1&pf_rd_r=146WQA1KAHRQE7P6JV6V&pf_rd_t=36701&pf_rd_p=2079475242&pf_rd_i=desktop.  

The plus with the OTC tester for MPI style (Bosch) injector tests (not for 2.5L TBI) is that it separates the injector from PCM and other issues like faulty wiring or grounds.  This standalone tool can fire and test an injector either on the engine or on the bench.  Read the reviews, very impressive!

Moses

Edited February 4, 2016 by Moses Ludel