[olddog]

Thanks. That helps.

Yes, Don it is MassFlow.

Rick - I do want to get it tuned at a dyno, but I think I have some problem components that need replaced first.

Maybe I should explain what I have been going through. I hope you can help me some more.

It has never idled well when started cold. It acts like its lean when cold, surges, and wants to idle down around 600 rpm cold, when set at 900 rpm hot. Hot it runs rich at low rpms by the smell, sooty pipes and plugs. Below 2000 rpm the engine is not smooth, I origonally chocked it up to the cam, but now I suspect injectors.

Oh yea 5.0 347 stroker, Edelperformer rpm heads, cam 236/242 durration @0.050 110 LSA. The MassFlow uses an Edel Vic Jr single plane intake with bungs welded in at each port.

Last summer on a 95 F day, I stopped to eat and a half hour later when I started it. It would idle Ok, but under load it would miss, bad. It wouldn't even free rev past about 3000 rpm. Acted similar to a rev limitter but much more erradic. I opened the hood and checked fuel pressure. It was ok. After the hood was open a bit it seemed to get a little better, so I babbied it down the road. After a bit it ran normal again. At the time, I assumed it was something electrical breaking down under load and when it cooled off it was ok. It did it again that day almost exactly the same circumstances.

I suspected it was the coil, but resistance measured right. I tried to make it do it again, buy letting it get hot idling with the fan off, but couldn't. Then it did it this spring on a 80 F day. so I replaced the coil.

After that I was playing around to see if I could lean it out some, so I temporarily dropped the fuel pressure from 39 to 28 & reset the ECU (power off) to see how it would act. To my surprise below 2000 rpm it was missing and sometimes it would have a cylinder hit real hard, as in the opposite of a miss (twice the power). Also in 5th gear at about 1500 rpm if I lugged it a little it would go into the miss fit like before I changed the coil. I could make it do it at will. I turn the fuel pressure back up to 39 and it was back to normal. Drop it to 28 and it would do it. Back to 39 and it was normal.

Now at this point I started to realize that what was normal definately had some misses and hard hits below 2000rpm. I think it always did it but I had chocked it up to the cam and rarely ran it below 2000 rpm. So I turned the fuel pressure up to 45 psi & reset the ECU. At this pressure it nearly took all the miss and hard hits out of it below 2000 rpm. It also started up cold buch better (not so lean). It still idles low, but it is very smooth.

Also when the fuel pressure is set down at 28 psi the pressure bleeds off fairly quick when you shut the engine off. The higher the pressure the better it holds when you shut it off.

Then it blew a fuel pump fuse going down the road. I replaced the fuse and when it started it went into the miss fit exactly like it did on the hot days. It took it about 10 minutes to come out of it. So at this point, I am sure it was not the coil and suspect it is injectors. I'm not sure if these big miss fits are the injectors leaking or sticking or if it they are shorting electrically. I do think at low fuel pressure they are leaking or not shutting off properly, but I'm not positive.

Any ideas on how to prove or disprove any of this? I plan to measure the ohm across the injectors cold and hot as soon as my back will let me.