More top swap help..

[thewronggrandprix]

So thanks to matt5112 I finally got the car running....But the joy was short lived. Here is what I'm dealing with right now.

1. Once I got it started the first thing it did was jumped to 4000 rpm and after about two seconds it slowly made way to about 500 rpm(just about died) and then right back up to 4000 again. It did that about three times and I never touched the gas. Is this a air flow problem or a sensor problem?

2. Once it finally settled down and by that I mean about 700 rpm or lower(just before death) if I touched the gas peddle it would just die completely. And if I started the car again it would repeat issue number one above. Would this be some kind of vac problem or is it also a air flow problem?

3. After letting my car sit for a day(mostly due to frustration) I came out to see if anything changed. Surprisingly something did change...It wouldn't start...I thought maybe it was because I dost plug it in the night before since the temp outside hit -15 so I decides to plug it in and wait awhile, didn't work..Thought maybe it was the battery being damn near frozen so I did the smartest thing I knew to do, I gave her a jump. Started right up but started doing issue #1 and #2 again. I decided that at least it was running and went ahead and disconnected the jumper cables and I course the car died. I'm pretty sure it's not the battery because when the key is in and turned to on everything works fine and usually when it is the battery the car won't allow you to remove the key from the ignition( that's been my experience) and somebody told me that maybe it's the alternator which I'm not sure about seeing as tho I've seen posts about people's cars not starting after doing a top swap. Should I go ahead and replace the alternator or is is it a simple to free fix? Sorry for the long haul again but I'm grateful for any help you guys can offer.

[dsmuts]

vacuum leak?

[machinegunsquid]

May very well be a vacuum leak for Problems #1 and 2.

as far as #3, get a meter and check to see what your charging output of the alternator is.


Also, make sure that your TPS is installed into the throttlebody correctly.

[thewronggrandprix]

Well issue 3 has been found and fixed. The battery was completely shot. Not really sure how that happens in a day but whatever, since I've been replacing everything else why stop now. But I think I found the vac leak and fixed the idle issue. Keeping fingers X'ed

[machinegunsquid]

^^ Good news.

My battery did the same thing, ended up having a cell go bad in it.

[thewronggrandprix]

Well I got a good part of issue one worked out a little better but she's still on the low side of rpms side. It won't die and start but it just sounds like it's got a massiv cam. I don't think it does so it worries me.

[matt5112]

If you have a compressor you could try pumping a little bit of pressure (under 10 PSI) into the vacuum system to see if you have any leaks. You'd have to seal off the throttle body inlet though.

The traditional methods for finding vacuum leaks tend not to work sometimes. For example, spraying brake clean around the EGR tube hardly ever shows anything. Yet it could be broken and leaking terribly. As such, check the EGR tube where it meets the LIM.

Did you put RTV in the corners of the LIM gasket where each piece meets each other?

Do you have another IAC you can try?

Is the TPS putting out 0.40 V or less when not touching the pedal at all?

Threshold for WOT is 4.0 V IIRC. Check those out.