if it popped the jboot off, then it could have popped one of the vacuum lines under the intake manifold "fingers" off, too... that was my problem.. Of course, I haven't read the 3 pages to see if you've tried this yet..

I did read that you checked all your vacuum lines, and you may have - but to be honest, this is still where my money is gonna lay...

I have triple checked the rotor. It is tight and moves with the cam.

Speedy:)

So you're saying that it points to cylinder #1 when the engine is at TDC?

I had a killer vacuum leak tonight and it was a pain to track down. It was on the bottom of the manifold, where the idle stabilizer I believe it is ties into the intake manifold. that was a pain to fix, but it solved the problem. I too had back fires, no idleing and the like...didn't blow the j-boot off though. Typically a vacuum leak that good though you can hear. Will the car start if you give it the gas? Mine did so I could hear the leak.

It better point to cylinder #1 at TDC since the TDC is measured at the #1 cylinder.

I pulled the fuel pump relay and jumpered 30 and 87B and measured the amount of fuel the pump pumped in 30 seconds. The result was 1,200 mL in 30 seconds. Clarks-garage says >850 mL is good. So the fuel pump is OK.

I reinserted the Relay and engaged the starter to trigger the fuel pump and I was getting good flow out the return line just like when I had it jumped. This telling me my relay is good as well.

I will turn the motor to TDC and check that the rotor is at #1 as suggested.

BRB

Speedy:)

I checked the rotor at TDC and it is pointing to the front cylinder.

I am going to pull the fuel rail, lay it on its side and try to start the car to see if the injectors are firing.

Speedy:)

The fuel injectors are emiting a nice spray pattern in pulses.

I am truly running out of ideas :(

Speedy:(

This is getting crazy.
 

OK, I re-re-read this thread again and I have to mention this only because it happened to me. I recently did some ignition improvements in the right front area of the engine compartment. When I was done, the car ran like $hit (similar to yours). I have no concept of how, but I managed to whack and crack one of my reference sensor connectors at the back of the intake manifold. It wasn't really noticeable unless you were specifically looking for it. I had to ty-rap the connection to hold it securely to the bracket, but all was (and still is) good after that. I was extremely happy that it only took me about 5 mins to figure it out. A true "DOH" moment.

Other things to ponder that were not covered yet:
- Test the coil with an ohmmeter
- How many miles (how old) on the ignition wires

Everything you tested (eliminated) so far is beginning to indicate an ignition problem.

Ignition wires have about 10,000 miles and 1 year on them.

I swapped out coils a month ago and it didn't make a difference but I just checked my MDS ignition coil on the car using the clarks-garage method of disconnecting the negative coil wire, unpluging the coil wire which goes to the distributor and placing a spark plug in its place, run a ground wire from the threaded part of the spark plug and then connect a wire to the ground on the coil. Tap the other end of the coil ground wire on the negative battery terminal and look for sparks on the plug. When I did this I couldn't get a spark. I even stuck the spark plug dirrectly into the coil terminal and tried again and got no spark. I check supply voltage going to the coil and was getting 12V.

I am going to try my other coil I have and test it in the same manner.

BRB

Speedy:)

I tried my second coil and couldn't get a spark from performing the clarks-garage procedure.

I pulled the coil from my Ford truck and tried it and the car still ran the same.

I reinstalled the MDS coil, pulled a spark plug and layed it on the intake while my wife cranked the car. I could see a spark but it was pretty wimpy.

Speedy:)

Not giving up yet.
 

Are you running a MSD Blaster coil with the stock Motronic DME? If so, are you using the required 0.8 ohm MSD ballast resistor?

If you answer YES and NO to these questions, you are burning up coils or hurting the DME and/or DME wiring. I explain in this thread:

http://forums.pelicanparts.com/showthread.php?s=&threadid=354156&highlight=ballas t

I will check tomarrow morning what kind of coil it is. I pulled it off of the 'S' I bought from Legion and installed it about 2 years ago. The car always ran perfectly.

Speedy:)

I also just re read this entire thing

I would do these things first

I think it is still a vacuum leak, they can and do create a backfire I have done it so many times it isn't even funny while tuning my setup. They will aso make it run rich under certain conditions.

You said you went and got some starting fluid? You need to spray it around various areas including the intake mating surface. Do little areas at a time. If the idle all of a sudden changes you have found something.

then if that doesn't work I would put the coil and dme back to stock no MSD at all see if and maybe re borrowthe early DME

then please repost what you find.

I will throw my old coil back on. I have an issue with trying to spray the area with starting fluid because the car doesn't idle by itself. The throttle needs constant stabbing to keep the car running. I can't perform both operations at once.

Maybe my lovely wife would be willing to take a "stab" at stabbing the throttle.

Speedy:)

Also, some food for thought on aftermarket ignition components and spark plug wire:

The factory wires are non-resistive straight stranded copper. The cable is rated 38,000 Volts. The RFI suppression resistance of the factory spark plug cable assembly is built into the connectors at either end.

Upgrading to an aftermarket "hotter" coil and/or ignition box will produce spark voltages as high as 45,000 Volts or more depending on the combination. You must also upgrade to aftermarket high energy ignition wires as well for several reasons. A higher dielectric strength is required to handle the higher spark voltage. A helical or spiral wound conductor is required to suppress EMI which could, in extreme cases, wreak havoc with engine computers and other electronics and to reduce the possibility of inductive crossfire between the spark plug wires. Some resistance is also needed to reduce RFI of wireless transmissions.

two things i am sure of: 1. go to lindsey racing garage help section and build a blink code tester: 4$ at radio shack and you can simply crimp it (85.5 fer sure, dunno on 83) 2. unless you tested fuel FLOW in addition to pressure, you did not finish testing your fuel supply; the pump will make adequate pressure with almost any flow. as old as your car is its possible you fuel tank screen got jammed durring your ten minute ride. check clarks-garage. hate to disagree w/ people who know more than me, but my understanding is vacuum leaks will not strand you, just make you run bad. also, DMEs rarely blow up unless wet. also, your AFM is self-adjusting; do not tinker w the insides unless you have Substantailly modified your car. i had the exact same problem bbut mine evolved very differently: it was blocked fuel tank screen, and my fuel pressure was perfect

When I checked fuel pump flow I got 1200 mL in 30 seconds compared to what clarks-garage says is acceptable ( greater than 850 mL). So my pump/ fuel filter are not restricting flow.

I reinstalled my original coil and tried to start the car and there was no difference.

I then had my lovely wife try to start the car while I sprayed the area with starting fluid. When I sprayed the starting fluid under the intake manifold beween #3 and #4 cylinders the RPMs jumped to 3000 RPM without any throttle input at all and the motor smoothed out with no pops and sputters. When I stopped spraying the car started to sputter again. I sprayed once more and the RPMs went to 3000 again. There must be indeed a HUGE vacuum leak under the intake manifold between #3 and #4. I will now pull the intake and investigate.


Speedy:)

BTW I was running the MSD Blaster II coil.

Speedy:)

I pulled the intake off and there is a vacuum pipe which is normally inserted into the bottom of the intake back by #3 and #4 cylinder. This pipe is about 1/2" in diameter and is steel. This pipe was disconnected from the intake. It looks as if it was epoxied in place from the factory and the epoxy finally gave way. Am I correct in this assumption???

I have some West Systems Epoxy I will use to put it back into place with.

Speedy:)