Fuel injector question

[88PA]

Hello all, driving home a couple weeks ago and car started running terribly rough, found bad #2 cyl. injector. Replaced the injector and all is well untill this evening when it started running rough again. Through process of elimination I think the same cylinder is dead again. Ok, on to the question.

The new Autozone injector we put in looked different, it was shorter, the business end of the thing that sprays the fuel was blunt and quite shorter than the old one. My brother said it was just the way the new ones look so we run it and it ran great until now. Before you ask, I did look carefully to see if the injector end was innerchangeable and it wasn't but the Oring configuration was a little different.

Since it has run great for 2-3 weeks then I suspect it is the correct injector but has gone south on me (it wouldn't be the first time a new part went bad from Autozone). Yes the plug is firing too, I pluged a known good plug into the wire end and started the engine and it was firing good, AND, it had the same miss.

Can anybody help me with this, I have my truck tore down right now and this PA is my only other source of transportation so I'm kinda in a pickle.

Thanks for ANY help!

[maxwedge]

See if you can hear the injector clicking/ticking, if not and there is pulse to it its bad, this is a nornmmal diagnostic procedure to check the inj. you could also check the resistance across the connector.

[88PA]

Originally Posted by maxwedge

See if you can hear the injector clicking/ticking, if not and there is pulse to it its bad, this is a nornmmal diagnostic procedure to check the inj. you could also check the resistance across the connector.

Yea, I did just that using the old screw driver as a stethoscope trick and determined the injector is pulsing. I have it narrowed down to the ICM. Is there anything I can do to help the ICM like clean a ground or something?

Thanks

[maxwedge]

Check for injector pulse first, none may indicate an icm or harness problem.

[wrightz28]

Just hit this up in your other thread the other day, make sure the spark plug wire on the coil pack isnt' getting knocked off by the firewall.

[HotZ28]

Since you posted this thread in the PA Forums, we can only assume the car you are inquiring about is a Buick PA. In addition, since there is no mention of the build year, other than your Avatar (88PA), we must again assume that the year it was built was 1988. If that is in fact the model year of your car, you have the Magnavox DIS ignition (coil/module) mounted on the front of the engine, far away from the firewall.

Please update your thread and let us know the year of your PA?

[wrightz28]

Originally Posted by HotZ28

, you have the Magnavox DIS ignition (coil/module) mounted on the front of the engine, far away from the firewall.

I believe up til 89 they were mounted over the "rear" valve cover, atleast that's where my 87's was.

[HotZ28]

The only underhood pic I could find of my old 1988 VIN3 3800! May she RIP!
Notice DIS mounted on the front side next to alternator & near battery.

[wrightz28]

Well I wash I ahs a pic of mine. That is the same motor setup I had in my 89 LeSabre but not the PA.

[88PA]

I don't think I had injector problems in the first place, I think it was ignition all along.
After putting another new injector into the same hole it didn't help at all so it was back to square one. I again checked for spark and low and behold there wasn't any. I replaced the ignition coil pack. When I fire it up it ran for about 30 seconds then started missing again just like it had been. By this time I am thoroughly discusted with the whole thing.

Fall back and punt again. This just didn't make since that one cylinder was dead when the coil pack is fed by the ICM by using three hot and one return, do the math. I began pulling injector connections thinking there has to be another dead cylinder, I found that a cylinder on the other side was indeed dead. I replaced the ICM and it now runs well except for a little bucking at around 45 MPH.

I know, poor troubleshooting on my part because I should have taken the ICM in to be tested before I paid 52 green for a coil pack. What I don't understand is why the thing ran fine for 3 weeks or so after we changed the injector and plugs if the problem was the ICM all along. This has been a strange on.

I did JB weld a cam sensor magnet in but still have the light so I need to look at that again.

Sorry about that, it's an 88 Park av. loaded with stuff like load leveling shocks (pump runs a lot) climate control, power seats, and stuff I don't know what they are.

The ICM is located beside the battery front passenger side.

Thanks for all the help!!!!

[HotZ28]

Thanks for posting the year! BTW, 1988 was the transition year to the 3X -18X_ DIS ignition system. Just for you Dylan, and to confirm you are on the road to recovery, they did have the rear mounted coil pack in 1987. I found a pic shown below of a 1987 VIN-3 with the rear mount.

[wrightz28]

Originally Posted by HotZ28

they did have the rear mounted coil pack in 1987. I found a pic shown below of a 1987 VIN-3 with the rear mount.

That was my baby

Now, you can see what I mean tho, when the front mounts become really flimsy, and the motor rocks back, drove me nuts when it did it, at idle the dang thing was fine, but under load it felt like a huge spark scatter from a points and condensor distrubuter. So finally I brake torqued the motor and low and behold she went all the way back and poof, just enough seperation.