I have an 89 Bonneville that has a miss on the #1 cylinder.I have replaced all plugs,wires and a new coil pack was installed a year ago.I know I am getting spark to the cylinder.Trust me...it let me know ...it lite up my day!
I did a check on the injectors by unplugging each one at a time.Well,I found the #1 cylinder had no change when I unplugged the injector.I replaced the injector and STILL have the damn miss.I even pulled the valve cover to see if the valves were opening.
So here it is...1)I'm getting air...2)I'm getting spark....3)I'm getting fuel...I think.
2 wires plug to the injector.One is a hot and one is a ground.I used a test light and found I have constant 12v power to the injector when ever the key is on.How can I check to see is the injector is pulssating?Can I place the test light lead to a 12v source then place the light to the ground side of the plug? Would this show if it is opening?
If not does the ground side go to the ecm?Or does it tie in with the other ground wires to the injectors?
You can't feel the miss when you floor the pedel.But when the torque converter locks it beats the hell out of ya.
I really need some help here guys.I'm ready to take a sledge hammer to this damn car.I'm trying to trade it for a full size ext cab truck.The guy probably wouldn't trade for a car with a miss.I know I wouldn't.

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[This message has been edited by Kevin S (edited October 09, 2000).]

 

Pep Boys (and similar places) sell these things called "test noids". They're little lights that plug into your fuel injector's connector. You plug it in, and watch the light- that tells you the wiring's okay.

As to the injector firing, well, maybe it's clogged. You need a digital multimeter with a 10Meg-Ohm "input impedance". Some of these don't have this fact listed on their spec sheets; I myself have a $5 DMM (same unit as my friend bought for $30) from http://www.harborfreight.com - and it doesn't have the 10MOhm input listed. Someone told me all DMM's should have this input, but I'm not sure about that.

ANYWAY, to check for an injector being clogged, you disconnect the electrical hookup from the injector. Put the DMM on it's ohms setting, and place the probes across the injector. You should see a resistance of 15-16 ohms.. anything way off from that, and the injector could be clogged.

I'm not sure about you tapping into the injector's ground wire to look for a test light flash.. I don't want you to blow your computer. I don't have any wiring diagrams for a 3.8 car without a distributor, either...

How is your crank sensor? My friend had the 2.5l I4 with the DIS & coil packs.. turned out there was a hairline crack in the crank sensor. When the car got hot, the crack would expand, and the sensor couldn't sense anymore. I think the main DIS unit went out a month or so after that.

You're not getting any computer codes, I take it?


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards

 

Not a sigle code!I thought that maybe it was clogged,but I put a new one in.
The way I want to do this test is like what the light does you are talking about.
On the injector plug...one wire is a constant 12v positive while the second is a ground.I'm assuming the ground is controled by the computer thru a solenoid of some kind.I plan on useing my test light by jumping the two wires together. By the way you described the "test noids" This should work.
I'm ready to roll this damn car into the river.......the bad thing is I live about 100 yards away from one

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[This message has been edited by Kevin S (edited October 09, 2000).]

 

Oh, the injector was new? Yeah I doubt it'd be acting funny like the old one- I thought maybe you tried a junkyard one.

Can you find out if the valves are opening & closing like they should? I guess with a compression tester?


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards

 

I do know the valves are opening.I pulled the valve cover to be sure.
Dad has a compression tester,I just need to find it

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[This message has been edited by Kevin S (edited October 09, 2000).]

 

Weird. It's gotta be electrical. Hey that DMM I bought for $5 is back on sale, but for $10 - 'course, it'll take a while to get here for your needs. Orders thru these guys over the phone get processed much faster than the internet.
http://www.harborfreight.com/cpi/taf...CategoryID=170


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards

 

Now I'm pissed !I check the plug to the injector and it has juice.The test light flashed pretty quick.
I have spark,I have fuel,I have air....what the fu*k else do I need?Nuclear power?

Now what?Do I throw the fuc*ing thing in the river or just blow the piece of sh*t up?

I'm going to look for dads compression tester today.If I can't find something wrong with this damn car,it's had it!

You guys will see me in the news for driving down main street here in Pt.Pleasant at 95mph towards the river.Just to see how far I can jump this piece of sh*t!

Did I mention I will be driving the wrong way on main street at 95mph?

GO***MN CAR!

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[This message has been edited by Kevin S (edited October 10, 2000).]

 

How'd the compression test go?

Is it possible something's blocking the spray pattern of the injector? Like, maybe your first injector lost a piece, it fell in, you put the new injector in over it?

What about a bad/old o-ring where the injector goes into the motor?

If you remove the plug and run the car for 20-30 seconds, do you hear the loud powerful whooshes of air? Can you smell fuel?

Try to run the engine with the plug IN and the plug wire UNHOOKED. I guess run it for a few seconds. Turn it off, and remove the plug- I think it'd be wet with fuel, right?

Is there something blocking the air intake port to that one cylinder?

Is the spark coming out when it should? Maybe you have spark, but it's sparking too early or too late, and trying to ignite a mixture that's not there? I'd say timing, but you don't have a distributor. Maybe that DIS box (or crank sensor) is shot? My friend's DIS unit on that 2.5 4-cyl was $130, maybe you can nab one cheap from a junkyard to try?

Remember to roll the windows down before the dive into the lake so you can get out okay!


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards

 

This kinda of behaviour plagues my Monte Carlo every once and a while. In my case it was always traced back to

1) a fouled plug
or
2) a burnt plug wire
or
3) bad EGR control solinoid

 

I've not had a chance to do a compression test,yet. As for the other things you have described I will have to try.

Before my last post on this topic I was ready to destroy this damn car.For the last 2 days it was hit and miss.Sometimes it would fire and sometimes it wouldn't.Maybe it's coming around

Dobber,I have done a tune up,new plugs & wires & no codes thrown in my face.


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[This message has been edited by Kevin S (edited October 13, 2000).]