Jump to content

Is there a way to test fuel inj...3.1MPFI - UPDATE: Test 6 individually, results


1990lumina

Recommended Posts

Title says it all basically. The Lumina is running like ass still, and it needs to get fixed so I can sell it. At idle isn't always trying to find somewhere to idle at but is bouncing between 300rpm and 1200rpm all the time. I've tried unplugging the TPS, MAP (there are two sensors back at the firewall, one is the MAP not sure what the other one is), IAC, EGR and O2 sensor thinking that the ECM might resort to open loop for that sensor and make the car run better but it doesn't seem to matter much.

 

The car only has 180,000km on it so I don't think the injectors could be THAT fucked up, but I'd like to test them anyways. Any way to do it without pulling the upper plenum off?

 

This spring with the Tech1 it was showing the long term block learn to be very low..like 100 or so. Apparently that means it's trying to pull fuel, but obviously the ECM is unsuccessful at doing it because it still idles like shit. The second you mash the gas it'll light the tires up and go still (as goodf as it ever did).

 

Plugs, wires, coils are all okay. Fuel filter has been replaced. Good fuel pressure. The PCV valve is new. The fuel pressure regulator checks out (no tears in the diaphram). I don't know WTF is wrong with this car. Other than a vacuum leak which I can't find I don't know where else to check.

Link to comment
Share on other sites

^^^That is not a proper way to test them at all...

 

Pull the plenum (takes like 10 minutes if that) and test them correctly.

 

Otherwise, you end up testing 3 of them and the wiring and connections for resistance.. And I have seen the early Multec injectors read very high and very low.. Should be self explanitory from there

 

Link to comment
Share on other sites

Don't forget that Ohm'ing them out can only really condemn one electrically if it's outta spec. Even if it's within spec, it could still be flowing incorrectly, so a balance test is the best way to test for this.

Link to comment
Share on other sites

(I didn't read all of the post originally), if you can get your hands on a vacuum gauge, hook it up to the manifold end of any and all vacuum lines, pump 'er up, and listen for leaks (engine off of course)

Link to comment
Share on other sites

Does Autozone or places like that normally rent out a tool to pulse the injectors individually to do a balance test? Since my car is OBD1 I don't think it's possible to do through the scan tool. And I don't want to spend over $100 on a tool I'll use once.

Link to comment
Share on other sites

The only way to acurately test the injectors is to pull the upper intake plenum. You can test the bank on the end harness. However, that tests all 3 at the same time. Since 12 ohm is the line for good, and one tests out at 10 ohm, and the other two test at 13 ohm. Its going to read 36 ohm, which would indicated a good ohmage, but there is a bad injector.

 

When one injector goes, it can make the whole bank of 3 run like ass or not run at all..

Link to comment
Share on other sites

I pulled the plenum and tested all 6 injectors, results as follows:

 

Cylinder:

1 - 13.2 ohms

2 - 8.2 ohms

3 - 13.2 ohms

4 - 9.8 ohms

5 - 7.6 ohms

6 - 12.5 ohms

 

From the above readings would you guys say this is why my car idles like complete ass (revs itself, hunting, etc..) I also believe upper plenum rear gasket was leaking since I had sprayed a bunch of Seafoam around that area and the gasket had on top and underneath all the way to the runners for cylinder 2 and 4.

 

Also, what's the trick to pulling the fuel rails? I want to see if any of the injectors are leaking, but they won't seem to let go of their hole lol. I have the 4 bolts out and the rails move around - just the injectors won't break free.

Link to comment
Share on other sites

You have BAD injectors. they may be responsible for your issues. need some injectors?

 

If you have 6 that are close to 12ohms I'd do anything to get some. How much do you want Ken?

Link to comment
Share on other sites

You have BAD injectors. they may be responsible for your issues. need some injectors?

 

If you have 6 that are close to 12ohms I'd do anything to get some. How much do you want Ken?

PM sending....

Link to comment
Share on other sites

I pulled the plenum and tested all 6 injectors, results as follows:

 

Cylinder:

1 - 13.2 ohms

2 - 8.2 ohms

3 - 13.2 ohms

4 - 9.8 ohms

5 - 7.6 ohms

6 - 12.5 ohms

 

From the above readings would you guys say this is why my car idles like complete ass (revs itself, hunting, etc..) I also believe upper plenum rear gasket was leaking since I had sprayed a bunch of Seafoam around that area and the gasket had on top and underneath all the way to the runners for cylinder 2 and 4.

 

Also, what's the trick to pulling the fuel rails? I want to see if any of the injectors are leaking, but they won't seem to let go of their hole lol. I have the 4 bolts out and the rails move around - just the injectors won't break free.

 

 

Time for ford injectors :lol:

Link to comment
Share on other sites

Thanks again for the offers Ken - if I didn't need the car back together during this week I wouldn't have bought the reman injectors. But time was the only reason I didn't buy from you!!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...