Injector tests Help
Thread Starter
Instructor
Joined: Nov 2001
Posts: 102
Likes: 0
From: Olympia Wa
Injector tests Help
Dose anyone have or know where I might find bosh fuel injector test procedures? :confused: working on a 85 L98 Tuned port system.......
[Modified by Cruzin I-5, 10:57 AM 1/2/2002]
[Modified by Cruzin I-5, 10:57 AM 1/2/2002]
Burning Brakes
Joined: Feb 2000
Posts: 958
Likes: 1
From: SF Bay area, CA USA
Re: Injector tests Help (Cruzin I-5)
I don't know of the exact procedures but here are a few things to try.
With the engine idling, disconeect the wire to each injector one at a time and listen for a change in RPM. All injections should have a similar effect on idle when you disconnect them.
With the engine off use an ohm meter to measure the resistance of each injector. They all should be near the same. I think 14 to 16 ohms.
If you find one that does not seem right listen to it with the engine running. Use an auto stephescope or broom handle to see if you can hear it ticking as it opens and closes. You can also use a volt metr to measure the signal at each injector to see if it is getting a signal. They make a special light to plug into the wire if you want to buy one.
Is there a problem you are trying to correct.
With the engine idling, disconeect the wire to each injector one at a time and listen for a change in RPM. All injections should have a similar effect on idle when you disconnect them.
With the engine off use an ohm meter to measure the resistance of each injector. They all should be near the same. I think 14 to 16 ohms.
If you find one that does not seem right listen to it with the engine running. Use an auto stephescope or broom handle to see if you can hear it ticking as it opens and closes. You can also use a volt metr to measure the signal at each injector to see if it is getting a signal. They make a special light to plug into the wire if you want to buy one.
Is there a problem you are trying to correct.
Race Director
Joined: Apr 1999
Posts: 13,002
Likes: 4
From: Paint Hill NC
Re: Injector tests Help (Cruzin I-5)
I would consider sending them to Rich at cruizinperformance.com. What I did was buy a matched set rebuilt. He sent them to me, I sent mine to him, no down time. Seems like it was less than $100 but that was 2 years ago, I really don't remember. If you just want them tested it is $5/injector I think. He is flowing one for me now, part of a set I picked up that nobody knows what they are (yellow top ford).
Harold
Harold
Thread Starter
Instructor
Joined: Nov 2001
Posts: 102
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From: Olympia Wa
Re: Injector tests Help (Cruzin I-5)
The main Problem I am haveing is an erattic running problem...... sometimes it runs smooth as silk and other times it just runs like a dog...... loss of power rough run ect...... I am just trying to Isolate the problem before i do a complete tear down....I have all ready done a a complete tune in cluding a new O2 sensor...... intermittent problems are such a pain...... The car is a daily driver (150 mile commute) exteded down time is not really in the cards..........
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Injector tests Help (Cruzin I-5)
Does it throw any codes? Run a fuel pressure check when misbehaving (lay the gauge under the wiper arm).
You might consider a scan tool. You could compare normal readings with problem readings and likely isolate the issues.
That symptom could be due to an intermittent in fuel, air or ignition.
You might consider a scan tool. You could compare normal readings with problem readings and likely isolate the issues.
That symptom could be due to an intermittent in fuel, air or ignition.
Thread Starter
Instructor
Joined: Nov 2001
Posts: 102
Likes: 0
From: Olympia Wa
Re: Injector tests Help (65Z01)
No Codes......... 38 - 42 psi.......(Running)
Of course it never acts up in a convenant place........... :cry
I have an OTC Scan tool From the old mechanic days.... and the pulsewith for the injectors seem normal..........
Im guessing that I have a coil in one of the injectors beaking down........:confused:
I just dont have access to all of the cool shop manuals any more...... :cry
Of course it never acts up in a convenant place........... :cry
I have an OTC Scan tool From the old mechanic days.... and the pulsewith for the injectors seem normal..........
Im guessing that I have a coil in one of the injectors beaking down........:confused:
I just dont have access to all of the cool shop manuals any more...... :cry
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: Injector tests Help (Cruzin I-5)
Check your MAF, MAF relays and ECT temp sensor. Those could be the source of problems. Also, try reseating the connectors on the ECM. I seem to recall that a guy with an Callaway turbo had intermittant problems like the ones your are having that were caused by bad connections on the ECM.
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LS/MFT
Joined: Jun 2000
Posts: 5,874
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From: Cary IL
St. Jude Donor '09-'10-'11-'12
Re: Injector tests Help (Cruzin I-5)
About a year ago I had a similarly irritating problem with my '90. No codes, erratic operation, etc. Tried everything: EGR, O2, EGR control solenoid, etc. Finally did a cold "ohm" check on the injectors and found two adjacent injectors with slightly low readings -- just at or below the acceptable threshold: 10 -12 ohms. Seems that because L98 injectors run in parallel, when more than one injector in a bank shows low resistance, this can cause a voltage overload and the ECM will cut out all four injectors then firing to protect the circuit. Replacing those injectors fixed the problem. I'd recommend that you check your injectors for resistance; takes about ten minutes and this will at least eliminate the injectors as the source of your problems.
Thread Starter
Instructor
Joined: Nov 2001
Posts: 102
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From: Olympia Wa
Re: Injector tests Help (SLOWBUSA)
to do an ohm test:
with the ignition off, remove the electrical connector at the fuel injector, (One at a time)with a DVOM (digital volt ohm meter) set the DVOM to do an ohm test accross the two termnals on the injector. it should read in the neighborhood of 14 to 17 ohms + or - 1 or 2 ohms.
well last night i checked all of my injectors and they are all consistant @ 16 to 17 ohms.
does any one have access to a Mitchal Manual with test flow charts???? :confused:
with the ignition off, remove the electrical connector at the fuel injector, (One at a time)with a DVOM (digital volt ohm meter) set the DVOM to do an ohm test accross the two termnals on the injector. it should read in the neighborhood of 14 to 17 ohms + or - 1 or 2 ohms.
well last night i checked all of my injectors and they are all consistant @ 16 to 17 ohms.
does any one have access to a Mitchal Manual with test flow charts???? :confused: