Freaken Car!!! Please Help!!

[Turbojorge]

O.K. Here's my problem. I am getting this huge Backfire coming out of the intake after 2-3 seconds on WOT. This was occuring before and I went threw the freaken mission of changing the cam, AND NOTHING!! So I put on a different coil pack and it went away--- for about three days and then the car died on me. (coil pack and module died) This was a 9 month old GM coil pack and module. So I went back to GM and bought a new coil pack and module (200 freaken bucks ) and the car ran like a dream. I changed the oil and the spark plugs over the weekend and got the car ready to go to the track. I was dialing it in with a street chip and Xylene last night at 19 psi and again. BOOOM! No freaken way man. Not this sh!t again. The new coil pack and module are about 3 weeks old and this is already happening. Whats wrong with my car?

BTW, I have Red Amstrong cables and yes the cam sensor and botton, along with crank sensor are new.

I don't know what else to do?

Something is killing my coil packs ( I think ) But what?

I don't know what else to do and I'm about to give up and sell it!
This has been an on and off problem since December of 01.

 

[y-hate]

check all your ground wires, including the one`s behind the passenger side head.....just a thought good luck

 

[QuickWrench]

I hate to be a stickler for the KISS rule, but let's figure a couple of things out.

1. Spark Plug Wires
a. Confirm that each are properly attached on each end.
b. Confirm that each wire goes to the proper plug.
c. Using an Ohm-meter, check each wire's resistance. Is one [or more] significantly higher or lower resistance?

2. Coil Pack
a. Confirm that all 3 mounting points of the locating bracket are firmly attached.

3. Engine grounds (this is a biggie)
a. Check for proper location and snugness of each of the engine grounds.
i. Battery Ground to front of engine.
ii. (2) ground connections from engine harness to rear of pass. side cylinder head.
iii. (1) ground connection from engine harness to rear of driver's. side cylinder head.
iv. Copper-looking ground from firewall to upper transmission bolt hole.

Also:
- Have you always been running Xylene when this happens?
- Have you had a competent shop test your alternator and voltage regulator at idle and breakover RPM speeds?
- If so, did they simply test its voltage output, or did they also load it and test the Current output?
- Are you running a Voltage booster of some kind?
- Any alarm systems? Big audio systems?
- Rear-mounted battery?
- Any other electrical-related issues? Fuses going? Starters? Bulbs too often?
- Has the engine harness ever been removed or replaced?

 

[matt87]

agreed! check those grounds and confirm fuel pressure!!!!!

 

[dpok69]

I had the problem of my car poping and dying on me after an intake manifold gasket change. During the change i painted the whole plenum and intake with hi-temp silver paint. This caused a loss of ground or bad ground at the mounting bracket (figured it out through a sharp member in this site who caught that).

So make sure the bracket is making good contact at mounting point on the engine and the coil pack base (i also lost one nut there).

Also make sure your passenger side relay bracket is mounted securly ( thats a ground point for those relays, ESC is also located there).

Pray that Steve Wood sees this post! He has helped me many times and is a Guru .

 

[Turbojorge]

Originally posted by QuickWrench
- Have you always been running Xylene when this happens?
- Have you had a competent shop test your alternator and voltage regulator at idle and breakover RPM speeds?
- If so, did they simply test its voltage output, or did they also load it and test the Current output?
- Are you running a Voltage booster of some kind?
- Any alarm systems? Big audio systems?
- Rear-mounted battery?
- Any other electrical-related issues? Fuses going? Starters? Bulbs too often?
- Has the engine harness ever been removed or replaced?

1. The car started doing this way before I even new about xylene. This is only the second time I do the 3 9 3 mix.

2. No, but I do have a volts gauge and it's usually at 14.2 or so when idealing and everything off. Drops below 12 at night with ac,lights, radio, and extra tranny cooler fan on. Hmmm.

3.Nope

4. No, I have the pump hotwired. I think I should get a volt booster when running more than 17 psi. Right?

5. A simple Clifford 700 IQ with dual sensor. That souldn't be a big deal. A simple 200 watt amp just to drive the concert sound. No subs.

6. Nope.

7. Starter IS kind of starting to wind funny sometimes. Hmmm.

8. No, But one thing I did notice from the wiring harness is that it has melted (somewhat) in the area directly above the down pipe. It has melted the fat gromet (spell?) that hold all the wires together. It does look like the lowest wire (wires?) may have suffered a bit.

I want to out and buy a new set of spark plug wires, But if the coil pack is indeed gone, what good is that going to do me? I'm I wrong?

Fuel pressure is set at 43 line off and rises to it's appropriate level.

I will borrow an Ohm meter tomorrow and get back on the rest of the thoughts.



Thanks for all the replies guys. You guys are great.

 

[Turbojorge]

What would the starters role be in all of this. I have blown the fusable link on it twice. Not recently though. I remember I used to have a bank account back then (It left me stranded at the bank). I'd say the last time that happened was about 6-7 months ago.

 

[Turbojorge]

After 2 somewhat "soft" pulls, I noticed that the backfire out of the intake is occuring when ever I go past 15-16 psi. I get about 2-3 degrees of KR when this happens, But I don't think it's real KR, It may think it is due to the LOUD explosion that occurs.

The boost gauge drops when the explosion occurs and I had to put a tie wrap on the vacume line that runs from the boost gauge to the top of the TB. (It poped out)

 

[blackbuick87]

Did you get that Ohmmeter today?

Also I would repair the damaged wire over the DP first since you will have to do it anyways.

If your voltage is dropping below twelve volts with all the lights and such on at night there is a problem with your voltage regulator or the alternator itself. These cars came with high output alternators and it should not have a problem at night

 

[QuickWrench]

1. When you can swing the $$, call Quad Air at (440) 235-3232 and pick up a Volt Booster. The additional full-throttle voltage may alleviate some of the issues you're experiencing, since they seem to occur at WOT.

2. How many miles are on the engine? Have you ever replaced the valvesprings? If this problem is the only true electrical gremlin you're experiencing, let's sharpen our focus. A problem like you're describing could also be symptomatic of weak springs, especially if the cam you installed is one with more lift/duration.

3. If you did change them, what kind did you use? Were the open and closed seat pressures set up properly?

4. If you've melted any of the wires on your engine harness, bite the bullet and get yourself a new harness. Please. Repairs to the original engine harness wiring are tedious at best, and very difficult to accomplish properly. Scotchlocks or some other solderless connector won't suffice as a repair, and a sufficiently acceptable solder-based repair is difficult to do properly, unless you have the proper equipment, solder, flux, and post-fix sheathing. This isn't like wiring a line-lock switch. Our OEM wires are BARELY sufficient already.

5. I'm intrigued by your starter issues. Let's check this out:
a. Disconnect the orange quick-disconnect near the battery, so the car won't fire when cranked.
b. With your Multimeter (MM), check resistance between the engine and chassis [with the car off, doors shut, etc]. Testing between a motor-mount bolt and a control arm nut often works well. The reading should be very nearly zero Ohms. Record the reading.
c. Switch your MM over to Voltage. 0 - 20VDC, or the next higher setting.
d. Check the battery voltage at the battery posts. Record the reading.
e. With your multimeter at the same two test points, (engine/chassis), have a friend crank the engine. Is there any voltage present while cranking? Record this reading, as well.

Back to work...

 

[Chuck Leeper]

While we're checkin stuff...

What does the POS cable look like?? IF it has the "bolt on" end at the batt, it HAS to go. Did or is the cable burned where it goes under the DP?? If it's the OEM cable, is it cooked to "well done" at the starter end, IE: at the end of the insulation it's corroded and very stiff?? If you are blowing fuseable links, then there's a major short, or they are routed wrong and have gotten too close to the exh.
Check the bolt that hooks the ground to the block/turbo support. Loose?? gone?? cooked due to being loose and overloaded??

If the system volts are dropping low, then the FP output is going to follow in direct porportion to the volt drop.

15-17# of boost on 93 is a stretch unless the engine is in GOOD shape and the tuneup is deadnuts on...

Given the starter is about toasted, what kind of connection "integrity" do you have w/ all the power wires that are there along w/ the POS cable??
Remember, if the load remains the same and the volts drop, the amp draw goes up and that can easily rise hi enuf to exceed the capacity of the links and other wires in the system.
Sounds to me like you need to start at the ft bumper and check, recheck EVERY wire, connection, system component, ALL the way thru the car to the rear bumper. [Take a GOOD look at the plug under the WS wiper motor. If it's full of corrosion/water, etc, that will cause all kinds of havoc.

1 last thot.. Since this happens only at relatively hi boost/power levels; what condition are the engine mounts in?? IF the engine is laying over , it may be getting into the POS cable, shorting it out, volts go in the toilet, the engine leans out, goes BOOM, you get off the throttle, the engine "gets straightened up", the short is gone and WALA!! it's running again...until the next WOT blast..


back under my rock

 

[ACME RACING]

Rich...

My car did this once at the strip, checked the o2 volts that were way too rich, .980 , leaned it down to .770 , and no more backfire. Have you checked the mixture, rich or lean ? alan

 

[Red Regal T]

MAKE SURE THIS IS NOT CAUSED BY A LEAN CONDITION. BE SURE YOUR FUEL FILTER IS NOT PARTIALLY CLOGGED. FUEL PRESSURE GAUGE WILL READ PRESSURE NOT FUEL AMOUNT. YOU CAN BLOW A HEADGASKET WITH BACKFIRES THROUGH TB. JUST SOME SUGGESTIONS.

 

[gofstbuick]

I want to out and buy a new set of spark plug wires, But if the coil pack is indeed gone, what good is that going to do me? I'm I wrong?

If your spark plug wires have excessive resistance, the spark will basically stop and return to your module, possibly frying your module and / or coil pack. So like Quickwrench says, check the resistance of your spark plug wires. If you have excessive resistance without a load on the engine, think about what's happening when your engine is running under a somewhat heavy throttle. I personlly don't like to see more than 7k per foot. jus my 0.02

 

[Turbojorge]

Re: While we're checkin stuff...

Originally posted by Chuck Leeper
1 last thot.. Since this happens only at relatively hi boost/power levels; what condition are the engine mounts in?? IF the engine is laying over , it may be getting into the POS cable, shorting it out, volts go in the toilet, the engine leans out, goes BOOM, you get off the throttle, the engine "gets straightened up", the short is gone and WALA!! it's running again...until the next WOT blast..


back under my rock

Wow! This could be it! But the motor mounts were changed about 9 months ago. (Both) And I do have the motor tied down with a strap.

I'm running xylene and fuel p. is at 46 line off! If anything, it may be too rich.

I'm buying new spark plug cable and putting them on when I get out of work know.

I'll inform you guys then.



Hey I really appreciate everyones help.

Thanks again everyone.

 

[gofstbuick]

Don't forget to use a little dielectric grease on the spark plug boots. This will insure that spark does not leak from the coil pack or from the spark plugs.

 

[matt87]

i had a backfire problem along time ago when i didnt know any better...turned out to be crappy kb red hot wires that i bought new failed after only two days. i saw little lightning bolt coming from one of the boots, change your wires and i'll bet you'll be fine.

 

[Turbojorge]

I went out and bought a brand new Multimeter. Before I went and bought new wires, I decided to Ohm out the existing Amstrong wires that have been on the car for about 4 months. Results: Excelent! Every wire was in between .83 and 1.07 ! Next was the coil pack. Results: 12.39 for 1 and 4, 12.43 for 2 and 5, and 12.39 for 3 and 6. I've been told that this doesn't really say anything. Is that true. I chaecked the volts on the baterry post and it was 12.3. The volts to all the grounds on the fire wall and 12.3 was the results. The 3 bolts for the Coil pack/ Module bracket and got 12.3 -.2 on them.

Un-pluged the orange cable and did the motor mount to control arm resistance test and got 001. Didn't have any one to crank the motor though.

I did notice that spark plug #5 wasn't completely tight. I removed it and it looked good, so I tightend it up and check the rest of the plugs. They all looked good. (they are 4 DAYS old)

However I did notice that the hook for the strap on the alterlator bracket had snapped off (the engine tie down strap) .

If the motor did lean over and touch ground, would it backfire like that and mess up my coil pack?

I put a new one on, started it up and went for a spin. The first WOT the car backfired again, but no where near as loud as yesterdays and the day before's pop. I then went 3/4 till sencond and then went WOT. NO Pop!
I mean if my coil pack went bad, why didn't it backfire when I went WOT? I'll admit that I am kind of scared of blowing a headgasket so I choose not to launch the car.

The coil/Module are still under warrenty, so I think I may swing by the dealer and pick up a new on.

Are my ohm numbers and volt levels good?

Thanks guy's.

 

[QuickWrench]

Allright, let's go down the other path. Let's just blindly assume for a minute that everything is electrically fine. That may not be the case, but for the sake of testing, let's try it. Forget the electrical issues for a few and concentrate on answering these questions so we can better assist you here:

Just wondering. You mentioned that this has been a problem since December. What changes, no matter how miniscule, did you make in the surrounding months? Any accidents? Floods? Caught in terrible weather?

1. Which JL chip are you running?
a. Did you get a new, correct burn for the latest mod's on your car? (Cheetah, 009's, etc.)
b. Is this chip set up specifically for the fuel type and boost levels you're running?

2. Injectors
a. Did you buy the 009's new?
b. Did you have them flowed?
c. Does the timeline of their installation come close to your problems starting?

There's always a possibility that one or more [even new] injectors may not operate properly across the range of duty cycles. Borrowing a set from a friend, or having yours cleaned and flowed will tell that tale.

3. Fuel Pressure
a. How EXACTLY are you setting the fuel pressure?
b. Is your gauge on a 36" or longer hose?
c. Have you checked the gauge against someone else's to determine proper operation of the gauge?

If your gauge is at the end of a hose, affix it in such a way that you can read the pressure AS THE CAR IS RUNNING UNDER BOOST. At-idle fuel pressure readings don't always cut it. You should see numbers very close to your static idle (vacuum off) fuel pressure plus one pound of fuel pressure for every pound of boost. Check this very closely.

4. Data
a. What methods, if any, are you currently using to tune the car? DirectScan? OTC?

If you don't have a tool like one of these, get one, borrow one, steal one, whatever. Post a decent set of results for O2 vs. WOT RPM, spark retard, etc. If you're running DirectScan, email me the data file at Quickwrench@Runbox.com, and I'll take a look at it.

 

[Turbojorge]

Well, I tried launching the car last night after I did all that I mentioned, and once the car reached 15psi or so... BOOOOOM!

It just dies, stumbles a bit, feels like it's going to shut off, and then it recovers, just like someone above said.

I had been using a friends OTC and on ocationally a T-link. I will be recording all data today and I will post it here. I'll try to get my friend to lend me his DS and if so then I'll send you the data. (Quickwrench)

As far as accidents, Floods, or bad wheather, none of this has occured. The only thing I can remember doing when this started happening was that I installed the Fuel pressure gauge on a 36" line. (an Autometer liquid filled 2 5/8 new gauge). Thats it. Actually, I attempted to install it, but didn't have the proper fitting so I left it for another day-- 1 month later. But after the first attempt was when this problem started occuring.

As far a chips go, The problem started with a Pitbull chip, then it did it when I went to the RA93 for a week (changed it quick cause I was getting about 10 miles per gal.) Now the JL 93 has been their for the past 3 months. It has 20* of timming. Thats all I know. It was made for 009's, but not for my Turbo or specificly for my combo.

I bought the car with the 009's and have never had them checked.

Fuel pressure gauge: How do I check it with someone else's? Do you mean remove it and try someone else's gauge?

I really don't think it's fuel. I bet If I swap coil packs, the problem will go away (As it has Three Times already ) But this wouldn't solve anything because their HAS to be something that is making them go bad. Could bad fueling situations cause coil packs to take a dump? If not then what???

IMO, something is causing my coilpack (and eventually module) to go bad, Quick too. The question is: What could be doing it?
I must have little crabs running around somewhere in this car.