So this is the issue I am having. I have gone nuts over it. I'll start with the basics.
Its a stock 84 engine, 87 gn turbo converted to work with hot air. 87 ecm 87 maf 87 module and coil adjustable fuel regulator stock base cut top with the adjustable top.
This first started way back when I had the 84 equipment on there. So I started slowly converting everything over to the newer 87 stuff. Through out this whole time I would constantly watch things on my scan tool keepin things at 20-30 iac count 40-45tps and my blms were around 125ish . Up until recently I was having issues with my iac. but I got them down to around 25 in closed loop.
So after swapping parts to the newer stuff this issue continued to follow. Just recently about two weeks ago. I was having issues with building boost it would slowly build then bam 12psi. ( But before after I swapped to the 87 turbo. you could floor it down shift n it would shoot right to 14 and boost control with take it down to around 11-12) This is when I found my blms to be around 110. At this time I was running the 84 maf on the 87 ecm. So I was like I must have to have a leak somewhere. I pulled everything off and found I have a few loose intake manifold bolts. I tightened them down put it all back together my blms went up to around 118. if I would lower the fuel psi I could get them up to around 128 but this was 20psi with vacuum n I am not comfortable with that. After this I would go for a ride and still slow to get full boost and the stupid idle surge.
I just couldn't deal with it any more so that night after work I went and grabbed the smoke tester. I tested at three points the vacuum block on the throttle body could get anything. Moved to the fuel pressure vacuum which goes to the main vacuum off the back of the manifold, then straight into the main vacuum. Still nothing only thing I could get was smoke coming out of the filter after the maf.
So today its a cold day started the car and it would run like crap which I knew from reading the 84 maf on the 87 ecm would cause this so no worrys. Cause today my buddy had a 87 maf that is know good, was took off his car when he went to the lt1 maf. Put it on and checked the scan tool and bam 128 blm in closed loop iac was 28. Put it in drive and it would still surge from about 11hg to 9hg. So I started thinking ok maybe its tps. Swap it out to another one I have and it was still there. But with the car running if I unplug the tps it will smooth out and the surge will get very small to nothing at all. I am stumped and don't know where to go from here maybe a 5.7 chip will help idk. any ideas will help.
Its a stock 84 engine, 87 gn turbo converted to work with hot air. 87 ecm 87 maf 87 module and coil adjustable fuel regulator stock base cut top with the adjustable top.
This first started way back when I had the 84 equipment on there. So I started slowly converting everything over to the newer 87 stuff. Through out this whole time I would constantly watch things on my scan tool keepin things at 20-30 iac count 40-45tps and my blms were around 125ish . Up until recently I was having issues with my iac. but I got them down to around 25 in closed loop.
So after swapping parts to the newer stuff this issue continued to follow. Just recently about two weeks ago. I was having issues with building boost it would slowly build then bam 12psi. ( But before after I swapped to the 87 turbo. you could floor it down shift n it would shoot right to 14 and boost control with take it down to around 11-12) This is when I found my blms to be around 110. At this time I was running the 84 maf on the 87 ecm. So I was like I must have to have a leak somewhere. I pulled everything off and found I have a few loose intake manifold bolts. I tightened them down put it all back together my blms went up to around 118. if I would lower the fuel psi I could get them up to around 128 but this was 20psi with vacuum n I am not comfortable with that. After this I would go for a ride and still slow to get full boost and the stupid idle surge.
I just couldn't deal with it any more so that night after work I went and grabbed the smoke tester. I tested at three points the vacuum block on the throttle body could get anything. Moved to the fuel pressure vacuum which goes to the main vacuum off the back of the manifold, then straight into the main vacuum. Still nothing only thing I could get was smoke coming out of the filter after the maf.
So today its a cold day started the car and it would run like crap which I knew from reading the 84 maf on the 87 ecm would cause this so no worrys. Cause today my buddy had a 87 maf that is know good, was took off his car when he went to the lt1 maf. Put it on and checked the scan tool and bam 128 blm in closed loop iac was 28. Put it in drive and it would still surge from about 11hg to 9hg. So I started thinking ok maybe its tps. Swap it out to another one I have and it was still there. But with the car running if I unplug the tps it will smooth out and the surge will get very small to nothing at all. I am stumped and don't know where to go from here maybe a 5.7 chip will help idk. any ideas will help.
Idk but there is a guy in my town that has an 87 fully restored when I heard it start up honestly it sounded like it had the same prob not appealing at all but his car runs great go figure
