ECMlink 90 DSM just put on SD need help with log

[unchuchable]

I have a 90 GST that I've been having problems out of.

When originally put on SD, everything ran fine but then I changed the throttle body and seemed to have all kinds of hell out of her for the last 2 years. Well I think I found my culprit in the MAP sensor connector was shorting out.

Now I've got her moving under her own power but I don't wanna mess anything up again so hoping I can post a few logs and have somebody with some knowledge help me out.

As stated the car is a 90 GST and mods are of course SD, FP manifold, bored .20 over then ARP headstuds and new gasket, Walbro 255 pump, TRE 1000cc injectors, FMIC, 2.5 turbo back exhaust AEM wideband in front O2, stock 14b turbo for now.

I am going to post 2 logs. First one is cold start and you can see how my AFR starts good then slowly goes lean. Second one is at operating temperature, it's only about 30 seconds long because the car dies and won't start back up. My battery jumper died so I figured this was at least a start to see what I may need to do to the car or in DSMLink.

Thanks beforehand with any and all help, its greatly appreciated!

 

[Stapl3]

The car doesn't idle at a VE % of 66.

Your engine idles at 1400rpm with a ISC value of 0 because there is air entering the engine somewhere between the throttle plate and back of the intake valves that shouldn't be entering.

 

[We're on Boost]

Kind of what I was thinking and why I asked. You got a preference to which one you think is better I start with?

I'd say check the butterfly position first, and if it's not the standard amount, adjust it per that paragraph in the Six Sigma article.

2nd, I think the flatter timing near idle will help your idle be more stable regardless of anything else you do, for as long as you have 1000cc injectors (or bigger) in it. So I'd change that and run a log. Low timing in that area doesn't hurt anything except a little tick down in your fuel economy and probably a change in emissions. There's no power there to speak of. As soon as you step on the gas a little bit, your Load Factor will jump immediately up to something higher than 0.4 so you are right back into normal timing again.

3rd, still with the low idle timing, add the weird VE numbers near idle which, like I said above, if it helps, I'd call it a workaround for some other problem that we just don't know what it is yet.

4th, lock it in open loop and log that.
By the time you are done with those things, you'll probably have a pretty good idea if one thing or another of them needs to be backed out. They are all simple settings, so none of it is super time consuming - except trying to run it to log it. In the last log when it was already hot, it didn't even want to start.

The car doesn't idle at a VE % of 66.

Right, that's why I said that if it helps, I'd call it a work-around for something else that is wrong.

Your engine idles at 1400rpm with a ISC value of 0 because there is air entering the engine somewhere between the throttle plate and back of the intake valves that shouldn't be entering.

Well, we didn't talk about the FIAV much. Just mentioned it on page 1 but nothing since then. Maybe that's it.

We should know if the throttle body is a 1990 or if it's a later one, because if it's a later one he could eliminate the FIAV with a bypass plate.

He has a lot of vacuum now though. 20 in/Hg at 1100 rpm. And his airflow I think is low for 1100 rpm. 0.5 and 0.6 lb/minute. If he had an air leak there, wouldn't he have less vacuum and higher Airflow numbers?

 

[We're on Boost]

@unchuchable Let's figure out what year car your throttle body is from. Should know if it's a 1990 or a 1991-94!

So here's a pic of the 1990 throttle body that was on my car 20 years ago. Looking at the small hoses, there are 2 on top (blue arrow) and another 2 down on the side (green arrow).

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Here's a pic of a 1991-94 throttle body on another guy's car 20 years ago. It still has 4 small hose nipples but they are all on the top (blue arrow). His are all capped off.

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Which one do you have?

 

[unchuchable]

Mine is a 90. I bought it may of last year refreshed by Josh Bachman. I tore mine apart Christmas time of ‘24. Gave it a good cleaning and put it back on in the spring.. that’s when everything went downhill car was running pretty solid prior to that. But cleaning it opened all the seals especially the seal on tps side was shot. So I sent mine to him as a core and bought one he rebuilt but still have not had much luck with the car. Glimpses of hope that I thought had it but not yet so then I finally decided to make a post and get 1st hand help with my specific scenario vs just scouring the internet over and over and trying things.

Here photos he sent before I purchased it

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[unchuchable]

@unchuchable Let's figure out what year car your throttle body is from. Should know if it's a 1990 or a 1991-94!

So here's a pic of the 1990 throttle body that was on my car 20 years ago. Looking at the small hoses, there are 2 on top (blue arrow) and another 2 down on the side (green arrow).

You must be logged in to view this image or video.

Here's a pic of a 1991-94 throttle body on another guy's car 20 years ago. It still has 4 small hose nipples but they are all on the top (blue arrow). His are all capped off.

You must be logged in to view this image or video.

Which one do you have?

So I got home and was starting to do adjustments and said he’ll with it and took the throttle body back off of the car and did the fiav delete since nothing extra is necessary to do it. Figured hell with it it’ll delete one possible cause but the car will never be winter driven anyways so no big deal. I am waiting on the silicone gasket to set up then will be reinstalling. I’ve chamged the timing table in link and have that good to go .. one reason I did it was I seen another post about closing the biss all the way and and if the car stays running it could be the fiav never closing so I did get the car to temp and closed the biss all the way and sure enough it kept running so maybe possibly that was an issue but if it was it won’t be now

 

[We're on Boost]

Here photos he sent before I purchased it

This is good that you have a rebuilt throttle body and also have really good pictures of it!

So I got home and was starting to do adjustments and said he’ll with it and took the throttle body back off of the car and did the fiav delete since nothing extra is necessary to do it.

Wait a sec - did you do all this just today?
Or was this done already before any of the logs that we've been looking at?

The FIAV delete that he did - was it basically screwing in that round plate all the way until it bottoms out - like shown in this Boosted Beaver video Closing the (1990) FIAV - The Free Way ?

Figured hell with it it’ll delete one possible cause but the car will never be winter driven anyways so no big deal.

Right.

one reason I did it was I seen another post about closing the biss all the way and and if the car stays running it could be the fiav never closing so I did get the car to temp and closed the biss all the way and sure enough it kept running so maybe possibly that was an issue but if it was it won’t be now

Right, good!
BTW you can still buy a new OEM BISS screw with o-ring and cap from STM if you need it.

 

[unchuchable]

This is good that you have a rebuilt throttle body and also have really good pictures of it!


Wait a sec - did you do all this just today?
Or was this done already before any of the logs that we've been looking at?

The FIAV delete that he did - was it basically screwing in that round plate all the way until it bottoms out - like shown in this Boosted Beaver video Closing the (1990) FIAV - The Free Way ?



Right.



Right, good!
BTW you can still buy a new OEM BISS screw with o-ring and cap from STM if you need it.

Yeah this was today and after getting that done I decided to do another boost leak test. Just for good measure after putting it back on. I definitely have air somewhere between intake and fuel rail releasing air I can hear it but with spray bottle and soap I am having a hell of a time tracking it down .. maybe I need a smoke machine or something cause I’ve been trying to find it for the last hour to no avail.

 

[unchuchable]

This is good that you have a rebuilt throttle body and also have really good pictures of it!


Wait a sec - did you do all this just today?
Or was this done already before any of the logs that we've been looking at?

The FIAV delete that he did - was it basically screwing in that round plate all the way until it bottoms out - like shown in this Boosted Beaver video Closing the (1990) FIAV - The Free Way ?



Right.



Right, good!
BTW you can still buy a new OEM BISS screw with o-ring and cap from STM if you need it.

Also yes that is the exact video I watch and I noticed he did the boost test afterwards . Also I sprayed around both sides of the throttle body and the biss screw hole and they checked out. I am good all the way up to the point where the intake meets the head somewhere around the injectors but no luck.. sorry I can’t figure out the quote thing I’ve tried a few times and it never does it for me.

 

[We're on Boost]

Yeah this was today

Awesome, that means from here on out you've got an improved (probably) mechanism there with the FIAV closed up.

I definitely have air somewhere between intake and fuel rail releasing air I can hear it but with spray bottle and soap I am having a hell of a time tracking it down .. maybe I need a smoke machine or something cause I’ve been trying to find it for the last hour to no avail.

Ok good I'm glad you are looking for that. I'm no expert on finding air leaks in this thing so I won't be much help with it.

sorry I can’t figure out the quote thing I’ve tried a few times and it never does it for me.

Do you mean this?

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Well if you are on a computer, you hold the left mouse button down while you sweep the mouse over the text you want. Then as soon as you let go of the left mouse button, that little Quote|Reply thing will pop up and you just pick one of them, I usually pick Reply. Then it will pop the quote into the spot wherever you had the mouse cursor sitting before sweeping the text you want.
I've never tried it on a cell phone or any other device that has only a touch screen, so I don't know how that works.

I'm always on a desktop computer with a nice full size Aula F108 keyboard that I like a lot, and a Logitech M550 wireless mouse that I also like better than any mouse I've ever had. I'm lousy on cell phones and the other mobile stuff and I don't like laptops either.

Before the Aula, I was using the last remaining Keytronics classic type keyboard from 4 that I had bought in, I think it was 2003. That was the type that looks like an aircraft carrier compared to modern keyboards, but that's what we always had for "enterprise class" keyboards at Boeing in the years I worked there and they were very good keyboards, easy to use. Well in later years Boeing got that stuff from Dell, but it was still pretty much the same.

 

[Tony1094]

Yeah this was today and after getting that done I decided to do another boost leak test. Just for good measure after putting it back on. I definitely have air somewhere between intake and fuel rail releasing air I can hear it but with spray bottle and soap I am having a hell of a time tracking it down .. maybe I need a smoke machine or something cause I’ve been trying to find it for the last hour to no avail.

Spray on the injector seats, I believe the injector seals are pretty common leak spots, especially if it sat for a while and rubber dried up/deteriorated. Super easy to fix.

 

[1990TSIAWDTALON]

And lower seals are cheap