Car Won't Run After Accufab SBTB Install - Ideas?

[SC Heaven]

Well not quite the weekend I had hoped for. Finally got around to installing my Accufab SBTB and plenum this weekend and now the car is out of commission.

When I first fired up the car after install it sounded like it ingested a cat. Very odd sucking/wheezing noise from the engine, followed by a very rough idle, stalling and a strong gas smell in the engine bay. I triple checked all my vacuum lines and sensor connections and couldn't find a smoking gun. After some research I found I needed to adjust my TPS voltage. Accufab recommends between .98 and 1.0v at idle, was able to get this set right in the middle at .99. This helped somewhat, but still odd noises and won't idle.

I began to wonder if the idle set screw on the Accufab piece was out of adjustment and starving the engine of air, so I put the stock throttle body back on to see what would happen. Same thing, rough idle, stalling, odd noise around the intake. Absolutely no idea what the hell is going on. I have a friend coming by with a spare FRPS tomorrow to try that out as I saw some threads saying those can go out without warning. But I'm not convinced it's my issue. It honestly sounds like it pulled something into the intake and is choking on it, but there was no packing material on or near anything and the filter and MAF are both clean. I also checked the IAC passageways and cleaned the IAC valve.


At this point I am very out of ideas and incredibly frustrated. Any ideas / thoughts / suggestions are appreciated. I tried to get some video but I didn't have anyone around to hold the phone and couldn't find anywhere to prop it up.

Thanks all.

 

[Senkak]

Could you have mounted your IAC backwards.
Seen it before.

 

[SSChris NY]

Could you have mounted your IAC backwards.
Seen it before.

Agree 100%

 

[SC Heaven]

Agree 100%

I actually took a picture of the engine bay to make sure I didn't do this exact thing. But after the first time I tried reversing it to be sure, wiring loom was short enough that it wouldn't let me turn it around. But I will check again tonight. Thanks guys :beer:

Any other thoughts / ideas?

 

[SC Heaven]

Just went and took a pic for comparison.

Pic of mine as it sits now:

Reference Pic from Google:

Looks correct from what I can tell. Is there a way to test the IAC valve to see if its working?

 

[KLLR SNK]

FRPS quickly comes to mind but so does a vacuum leak or torn gasket around the plenum area if that is all you changed. Since you set the TPS Check the IAC and the FPDM voltage. The TPS could also have a dead spot in it.

 

[SC Heaven]

FRPS quickly comes to mind but so does a vacuum leak or torn gasket around the plenum area if that is all you changed. Since you set the TPS Check the IAC and the FPDM voltage. The TPS could also have a dead spot in it.

I actually ordered all new gaskets from Accufab pre-install, so I'm not too worried about the gaskets having failed. And it feels very vacuum related, but all the lines are solid. Do you know off the top of your head where the IAC voltage should be? I'm not sure how to check if the IAC is bad short of swapping it out.

Also not too worried about the TPS voltage having a dead spot, as I set the idle voltage correctly, and when I start it up I'm not applying any throttle in fear of damaging something, so in theory it should be sitting at .99v the whole time.

I will do some research and check the FPDM tonight. A spare FRPS will be swapped in tomorrow to rule that out. Thanks for the sugestions. :beer:

Keep the ideas coming. All help is appreciated.

 

[Riddick]

Try slapping your stock TB back on and see what it does then.

 

[SC Heaven]

Try slapping your stock TB back on and see what it does then.

I began to wonder if the idle set screw on the Accufab piece was out of adjustment and starving the engine of air, so I put the stock throttle body back on to see what would happen. Same thing, rough idle, stalling, odd noise around the intake.

Already done. ;-)

 

[03SonicVert]

Did the IAT fall out of the JLT elbow?

SV

 

[SC Heaven]

Did the IAT fall out of the JLT elbow?

SV

Just went and checked. IAT is snug and happy. Triple checked the MAF connector as well. Nothing out of place.

Thanks for the suggestion. :coolman:

 

[oldmodman]

It sure does sound like you have developed an air (or vacuum) leak somewhere. One fairly easy way to look for it is to get a propane torch, turn it on unlit and direct the gas flow to various points around the engine while it is idling. If the revs suddenly pick up and smooth out you have narrowed down the location of the leak. I was trouble shooting a car once (not a Ford or blown) and found an air leak that had me pulling out my hair all day. It was a hose that had gotten knocked off of an area that wasn't even being worked on. And it was so buried that I would never have found it otherwise.

 

[KLLR SNK]

Looking at your pics I am not certain if there are sensors or regulators somewhere on the CC or throttle cables (under the dash - in the PCM, etc) but I would put them back on to make sure they were not causing the problem. I know it sounds stupid but the group has covered most of the bases generally related to your issue.

 

[SC Heaven]

It sure does sound like you have developed an air (or vacuum) leak somewhere. One fairly easy way to look for it is to get a propane torch, turn it on unlit and direct the gas flow to various points around the engine while it is idling. If the revs suddenly pick up and smooth out you have narrowed down the location of the leak. I was trouble shooting a car once (not a Ford or blown) and found an air leak that had me pulling out my hair all day. It was a hose that had gotten knocked off of an area that wasn't even being worked on. And it was so buried that I would never have found it otherwise.

I think I have an old torch in the garage somewhere. I will give this a shot. Thanks. :coolman:

Looking at your pics I am not certain if there are sensors or regulators somewhere on the CC or throttle cables (under the dash - in the PCM, etc) but I would put them back on to make sure they were not causing the problem. I know it sounds stupid but the group has covered most of the bases generally related to your issue.

I'm not sure that there are any under there or not. But I will take a look. At this point nothing sounds stupid as this has got me all sorts of confused. Got a Ford mechanic coming over tonight to help me trouble shoot. I will post up what we find. I'm hoping it's not something stupidly simple, but it probably is and is probably why I am missing it.

Thanks everyone for the help. :beer:

 

[hotcobra03]

The rest of air inlet is connected...ait and maf

 

[SC Heaven]

Well, after a full blowerectomy last night, the problem was found. Somehow when I was installing the new TB the first time, I missed a piece of gasket when cleaning the surfaces and the blower ingested a nickel size piece of old gasket. There were several other much smaller pieces that fell out as well. That explains the noise the car was making, but it was amazing that such a small piece was choking the car. My best guess is the gasket was wedged in between the front of the blower housing and one of the rotors and it was slowing the rotors down (just a guess).

So with all of the crap out of the blower, I cleaned out the valley, cleaned and resealed everything, put it all back together and she is back to purring like a big angry kitten. I was relieved it wasn't more serious, as the sounds it was making had me convinced the blower was near death. In the end it cost me nothing more than time, but I (re)learned the importance of prepping and cleaning everything properly.

Thanks all for the help and suggestions with this. :coolman:

 

[whitedevil95]

Glad you got it figured out.