turbo...sssssss, flut, flut, pop, sssss - Intermitent

[cesarp]

I'm clueless. I have an 84 Hot Air. Replaced the following: fuel filter,pcv valve, egr valve, spark plugs AC at 0.32, new 8mm wires.

I've checked fuel pressure at it sits at 30~31 PSI at idle and 37~38 with the vacuum hose off.

I've turn down the boost to 10 PSI and I still get popping.

Knock gauge lights up sometimes on the first 1 or 2 green lights. The popping sometimes is very loud, sometimes not as loud. Like it flutters. flu,flu, flu, pop.

This is ONLY under boost on hard accelaration and very seldomely under light accelaration .

I hear a light tik, tik , tik somewhere in the fron of the engine. Somewhere in the pulleys area.

I don't want to give up on it. The car runs real good most of the time except for that annoying and sometimes enbarassing POPPING !!!!

Don't have scantool just the knock gauge. The knock that it sometimes read, I believe is because of the popping is sometimes loud causing it to be false knock but not sure. When the popping is light then I get no green lights.

This is if I'm just gunning the pedal. I will try my best to simmulate :

turbo..ssssssss, flut,flut, pop, pop, ssssssss

is intermitent.

 

[6SENSE]

I'm clueless. I have an 84 Hot Air. Replaced the following: fuel filter,pcv valve, egr valve, spark plugs AC at 0.32, new 8mm wires.

Your symptoms, and the fact that you just got finished changing plugs/wires sound like you need to go back over wire placement. First make sure the wires are to the correct cylinders. Also make sure the boots are down tight on the plugs.

I hear a light tik, tik , tik somewhere in the fron of the engine. Somewhere in the pulleys area.

This sounds like Crank Sensor misadjusted and hitting. Before messing with it though, open the hood at night with the engine running and see if you see any spark arcing anywhere. This will also cause a "tik" sound and the issues you described (hence the reason for checking the plug wires first). The sound of a misadjusted crank sensor hitting will be annoying, but most likely wont cause any performance issues. Unless it has been happening long enough that it has actually broken part of the sensor. If this has happened you would have some problems when starting the car. Do you?
I would focus in those areas first but you can also make sure nothing is out of whack with the vac lines from doing the EGR and PCV.

 

[cesarp]

well, we put the car to a scope. The # 1 cylinder seems to be the problem.

I checked the gap on all new plugs but noticed that the #1 spark plug seem like is not even firing because the is the only plug that almost looked new.

I don't want to just start buying parts without knowing for sure what it is.

#1 - is the problem for sure.

should I go ahead and buy a coil pack from Auto Zone and Adapter for it to fit an 84 hot air ?

I'm thinking it could be the injector# 1 also but not sure.

The coil pack towers are reading 13.50 give or take a few but there pretty much even all accross.

Any ideas guys....

 

[6SENSE]

Our "C3I", distributorless ignition systems, use a "waste spark" method to distribute spark. Each cylinder is paired: 1&4, 2&5, 3&6. Spark is simultaneous between two cylinders (one coming up on compression stroke, one on exhaust). IMO, I dont think that your coil pack is the culprit.
Could be the ignition module. Testing resistance across the towers of the coil tells nothing about the state of the module. Sorry, not much as far as testing this. Casper's makes a tester that tests both the module and coil pack simultaneously. It simulates actual engine load as if you were driving (this would be good for you situation). Other than that its good old process of elimination.
Another thing to check is at the injector (as you mentioned). Get ahold of a noid light. This is a tool [tester] that plugs into the injector plug (connector) so you can see if it is firing. You can pick one up at AutoZone. See if that #1 injector is firing (crank engine and watch for light to blink).
There is a chance that the ticking sound you described could lead to the problem. If the sound is the crank sensor, and it is damaged from rubbing the interrupter ring, it would cause driveability problems. If you have any type of scan tool (or a tach), monitor rpms while driving. If the #s are erratic it would indicate that the ECM is not receiving a proper reference pulse (probably bad crank sensor).
I have never heard the sound that people have described their bad cam sensors making, but possibly the sound you described? This would be in the same vicinity that you described your sound. Well, the ign mod monitors crank and cam sensor signals and passess the info on to the ECM to take care of spark and fuel timing, so both your cam and crank sensor must be giving SOME sort of signal. If they werent, the car wouldnt start.

Of course the cause could be the ECM itself.

Id check these possibilities. Especially in the case of the ECM or ign module, it would help if you had another known good unit that you could just swap to rule out possibilities (this is sometimes a must when it comes to the process of elimination).

Any trouble codes? Maybe 41? Also, what did the other plugs look like?

 

[cesarp]

no codes. The plugs after a weeks use look normal. The #1 looks like it barely gets to see any action.

It is firing, I even changed that #1 spark plug with a new one. Also a new wire and it's still missing.

Since the spark plug itself seems to new, I'm thinking that gas to the #1 injector is not engagin or the injector is just completely clogged.

This would mean that the spark plug is firing but there is no gas or very little to that injector.

The scope showed all of them were firing fine but the #1 will missfire or it was irratic just on that # 1.

 

[6SENSE]

At this point I would try to eliminate the injector possibility. Get the noid light to check that its firing. Then check the injector itself. Maybe something (i.e. dirt) got into the line when changing the fuel filter? Filter facing correct direction, right?
May be a problem with the cam sensor, which finds #1 (1&4) to start its signal. The signal which is also responsible for injector timing (through the ECM).
After checking the injector, swap the ECM, then module, then if problem still exists its time to look closer at the cam sensor.

 

[cesarp]

Here is what I'm getting when I test the coil pack after driving it and letting it sit for like 5 minutes.

Coil pack
1-4 = 13.80
5-2 = 13.75
3-6 = 14.20

Does this definetly mean the coil pack is no good under HEAT !!!

 

[cesarp]

thanks to everyone that helped me !!!

I went to Autozone and they tested my coil pack. It tested fine and it showed to be ok according to specs. I was kinda disapointed because I tought that would for sure state that the coil pack was bad. The manager said "It's not the coil pack" ....

Guess what ?

I still bought it with an adapter to fit the 84 Hot Air.

It was the coil pack oon:

Even though it tested fine it was no good !

I'm happy....

 

[6SENSE]

Originally posted by cesarp
thanks to everyone that helped me !!!

I went to Autozone and they tested my coil pack. It tested fine and it showed to be ok according to specs. I was kinda disapointed because I tought that would for sure state that the coil pack was bad. The manager said "It's not the coil pack" ....

Guess what ?

I still bought it with an adapter to fit the 84 Hot Air.

It was the coil pack oon:

Even though it tested fine it was no good !

I'm happy....

Happy for ya . Until the part where you said "Guess what?" and that you went ahead and bought the coil pack, I was trying to get my eyebrow to stop going up. Kind of looking like this : .
Auto Zone is testing coil packs now!? What did they use to test it? Specs are 11-13k ohms, not 11-14k. Anyway, glad it was an easy fix. Always start with the easy stuff first. Again, swapping parts always helps, especially with something easy to swap like the coil pack. I remember buying one a long time ago for a 3800 car just to see if it was the problem. I was real carefull with it so that I could turn around and return it .

 

[cesarp]

Auto Zone showed the specs to be

11 ~ 13.50 at the secondary side (towers)

0.03 ~ 1.00 on the primary side (bottom of coil pack)

They used a Digital Multimeter

 

[6SENSE]

Cool, you must have one of those rare AutoZones with someone(s) that actually knows something about what there doing . Unfortuneately on more than a few occasions, when I went into the AZs around here, Ive felt like I should have been on the payroll.

 

[6SENSE]

Oh yeah, it can be kind of an intermittent problem. When you got the high readings yourself vs. their "good" readings, that is often the norm. Heat can play a role with electronic parts. For example ignition modules on GM HEI distributors will often [initially] test good, but if they try the test a few more times (and theyre supposed to) until the module gets hot, it will fail the test. This is when the problem usually occurs with these types of parts: underload /or warmed up.