Possible MS problem, with 3.1L MS1 EDIS V3

[Trys_Hard]

We have been struggling with Sourpuss for a while now and have not been able to figure out what is going on. First some background:

 

 

 

 

The car was running great, was recently dyno'd at 239RWHP. Then the owner came to us and said he blew out the manifold gasket and had a huge backfire out the intake. He dropped the car off for us to replace the manifold gasket. We replaced the gasket but now the car runs like crap. KPA is at 97, has no power the AFR is all over the place and the header will start to glow red at idle, even though the MS and the standalone LS1 read AFR in the 12-13 range. The engine was not generating any vacuum, I was able to get some vacuum by adjusting the timing but still not up to spec. Our vacuum gauge reads about 8" of vacuum at idle, before I adjusted the timing it was at 3". This is all on the same map that the car dyno'd on.

 

Engine Specs:

 

3.1L, with MSA Stage II Cam Kit, Ported Polished head, Lone wolf intake, 60mm TB, 6-1 Header, MS1 V3 running MSNE with EDIS, using a coil pack and controller from a 94 Ford Contour, Mustang SVO 35# injectors, 100GPH fuel pump and Aeromotive AFPR.

 

 

 

 

 

This is what has been replaced or checked:

 

Replace or checked all vacuum lines, there are only three on the engine, Brake Master, ECU and FPR lines.

 

 

Replace EDIS Coil pack and control unit.

 

Had MS1 checked out by Symtech and they report the unit is working properly.

 

We have changed the injectors, FPR, and fuel pump.

 

I have bumped up the timing and gave it more fuel got it to run a little better but still no power.

 

We also have tested the map sensor with our vacuum gauge.

 

 

 

 

The compression is 210 across the board, and we did a leak down test which also came out OK.

 

We have checked the cam timing many times.

 

 

 

 

I am including a recent datalog, an old datalog when the car was running correctly and the current MSQ.

 

 

 

 

Links to datafile and msq

 

MSQ

 

Current Datalog at Idle

 

Old DL when car was running good

 

Thanks in advance for any help.

 

 

 

 

Art Rinner

Sunrise Z

[mobythevan]

Have you tried pressurizing the intake and checking for leaks? I do this routinely with my eagle talon.

[Trys_Hard]

Have you tried pressurizing the intake and checking for leaks? I do this routinely with my eagle talon.

 

He has a lone wolf intake, very simple, and just three vacuum lines. We have removed and inspected the intake and sprayed carb cleaners all around it to no effect. There are no vacuum leaks.

[mobythevan]

The car was running great, was recently dyno'd at 239RWHP. Then the owner came to us and said he blew out the manifold gasket and had a huge backfire out the intake

 

A kpa of 97 at idle tells me the megasquirt MAP is reading atmospheric pressure, no vacuum. The only time I have seen that was when I forgot to connect the vacuum line from the intake to the megasquirt MAP sensor. Since I am sure you have the line connected I say it is a bad MAP sensor, whoever tested your megasquirt probably didn't do anything to test the MAP sensor, they likely just said "hmm, 97 kpa looks like it is working since it is not connected to an engine"

 

Huge backfire = dead MAP sensor.

[Trys_Hard]

A kpa of 97 at idle tells me the megasquirt MAP is reading atmospheric pressure, no vacuum. The only time I have seen that was when I forgot to connect the vacuum line from the intake to the megasquirt MAP sensor. Since I am sure you have the line connected I say it is a bad MAP sensor, whoever tested your megasquirt probably didn't do anything to test the MAP sensor, they likely just said "hmm, 97 kpa looks like it is working since it is not connected to an engine"

 

Huge backfire = dead MAP sensor.

 

I thought the same thing, but when we put a vacuum pump on it and drew 12" of Vacuum the Map Sensor on the MS read about 45KPA which indicates it is working. And we put the Vacuum gauge on the car and it was actually only pulling about 3" of Vacuum.

Edited April 1, 2010 by Trys_Hard

[mobythevan]

It seems you have checked everything that could cause the vacuum problem mechanically(cam timing, compression, intake leaks). How is the EDIS trigger wheel and sensor mounted? Could something have slipped in this area. I guess I ask the question if cam timing is good, valves are not bent, and compression is good, then what else in an engine can cause no vacuum when you fire it up? The glowing header is indication of retarded ignition timing. I think your problem is purely ignition related based on the details you provide. If I was in your situation and you've already beat your head against the wall for a while then I would throw an 83 turbo dizzy on the engine and see that everything works OK with the simpler setup before debugging the EDIS system. Assuming something went south on the EDIS system then what could it be? I'll throw out some things I have heard that could be wrong with EDIS systems: spacing between sensor and trigger wheel changed, two sensor wires are reversed, sensor wire noise/shielding, meqasquirt tooth settings.

 

The final question, what does a timing light show during cranking? Nice and steady at your fixed angle setting or all over the place? I don't see anything in your posts about checking the ignition timing with a light. I know it is possible because I check my wasted spark LSx engine.