my van is not hitting on the middle cylinder on the passenger side new plug new wire . it has 150 psi compression does this mean ive got a bad injector? can you tell me how to test the injector?

 

A new plug and wire does not guarantee you are getting spark. Verify spark first. If you do in fact have good spark. A weak spark is the same as no spark. Next, check to make sure the injector is getting a signal. If the signal is present, then the injector is bad. If the signal is not present, then the wiring has been damaged, the connection and the ECM is corroded, or the ECM is faulty. If the ECM is faulty, replace the injector anyway, bad injectors is the most common cause for injector driver failure.

 

which engine, 3L or 4L?

please pull codes and post on forum
http://fordfuelinjection.com/?p=13
even the '90 3L SFI ECU records individual cyl. misfires in codes
http://fordfuelinjection.com/index.php?p=14

pre '96 3L with failed spark on one cyl. can be rotor cap problem

4L will ALWAYS miss on 2 cylinders if there is a ECU/coil pack/ign. wire problem because of EDIS. 3 sets of 2 cylinder plugs each seried wired and fired.

if one injector is plugged, replace all with tested matched balanced output spray pattern tested set of 6. Ford's 60 degree bank V6s are not the smoothest running engines even straight out of the factory with everything to spec.

tough to pull the injector wiring electrical plug while engine is running at fixed rpm on an Aero while monitoring rpm but a good shade tree mech. technique to test injectors.

per Ford Serv CD
Cylinder Balance DTM--SFI Engines Only
"NOT APPLICABLE TO PRE '96 4L ENGINES WITH BANK FI

The purpose of the cylinder balance test is to assist the mechanic in finding a weak or non-contributing cylinder. The test is entered by depressing and releasing the throttle within two minutes after the Engine Running Self-Test DTC's have been output.

Once the test is entered, the IAC duty cycle is fixed and the engine is allowed to stabilize. Engine rpm is measured and stored for later use. Next, the fuel is shut off to cylinder number 4, 6 or 8, depending on engine. After a brief stabilization period the engine rpm is again measured and stored. The injector is turned on again and the process is repeated for each of the injectors down to one. At this point, the maximum rpm drop that occurred is selected from the table of rpm drops for each cylinder. This maximum rpm drop is now multiplied by a calibratable percentage. The resulting number (rpm) is now used as the minimum rpm that each cylinder must have dropped to pass this test.

Example: 150 rpm x 65% = 98 rpm

If all cylinders drop at least this amount, then a code 90 is output indicating a pass. No further testing is necessary. If a cylinder did not drop at least this amount, then the cylinder number would be output. For example, 30 for cylinder number 3. This indicates that cylinder number 3 is either weak or non-contributing.

The test can now be repeated a second time if the throttle is depressed and released within two minutes of the last code output. This time the maximum rpm drop that occurs is multiplied by a lower percentage. This number is now used as the minimum rpm drop for each cylinder to pass this test.

Example: 150 rpm x 43% = 65 rpm


The test can be repeated a third time by depressing and releasing the throttle within two minutes of the last code output. This time the maximum rpm drop that results is multiplied by a still lower percentage. This number is now used as the minimum rpm drop for each cylinder to pass this test.

If all the rpm drops are greater than 30 rpm then a code 90 is output. If cylinder number 3 had failed the first and second level, but passed the third, then it is considered to be a very weak cylinder. If cylinder number 3 failed the third level then a code 30 would again be output. In this case, cylinder number three would be considered a non-contributing cylinder.

The Cylinder Balance DTM may still be repeated as many times as desired by depressing and releasing the throttle within two minutes of the last code output. All further testing (i.e. 4th, 5th pass) will be done using the third level percentage.
POSSIBLE CODE OUTPUTS
(code 30 is used as an example only)
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
³ LEVEL ³ ³ ³
ÃÄÄÄÄÄÄÂÄÄÄÄÄÄÂÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³ 1 ³ 2 ³ 3 ³ INDICATION ³ POSSIBLE EEC CAUSES ³
ÃÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³ 90 ³ X ³ X ³ Indicates a pass, all cylinders ³ ³
³ ³ ³ ³ contributing equally. ³ ³
ÃÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³ 30 ³ 90 ³ X ³ Indicates a weak cylinder. ³ ù Partially clogged injector ³
³ ³ ³ ³ Cylinder is firing, but not ³ ù Injector/harness resistance out of ³
³ ³ ³ ³ contributing as much as the others. ³ specification ³
ÃÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³ 30 ³ 30 ³ 90 ³ Same as above, but more severe. ³ ù Same as above, but more severe ³
ÃÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³ 30 ³ 30 ³ 30 ³ Very weak or dead cylinder. ³ ù Open or shorted circuit ³
³ ³ ³ ³ ³ ù Loss of injector drive signal ³
³ ³ ³ ³ ³ ù Fully clogged injector ³
ÀÄÄÄÄÄÄÁÄÄÄÄÄÄÁÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
X = no further testing necessary

 

i must have been half asleep last night when i posted my question its a 3.0, it does have nice strong blue spark also i did put in a new cap and rotor and plugs last night before i posted here. plugs where well used but very clean burning even the cylinder not working . oh i did unplug the three injectors on that side one at a time could tell the difference in the first and the third cylinders but no difference in the middle one at all . i have no flashing on the dash . ill break out the code reader this week end
thanks guys

 

The guys are right about replacing injectors, when one goes south, it is best to replace all of them. If they do not all flow the same amount or with the same spray pattern, the engine will never run right.

 

Another test could be to move the injector to another cylinder & see if the unplugging produces the same result on the new cylinder. If so it's bad. Tried spraying injector solvent into the fuel rail?
This test would also prove that the PCM is producing a signal to fire the injector. If it stays in the same original cylinder you have a computer or electrical problem.

Aeroman.

 

well guys its fixed it was the injector im sure glade it was on the passenger side that other side looks meaner than a snake to get to. gona stop at one for now it seems to run just fine if i need i will change them all later . with 275,000 miles i dont really to spend much on it. its sure been a goodun wish i could find five more just like it hey thanks for your help guys

terry travis charlotte tn