Need some input -> Problem with 3.2 transplant going lean and misfiring after two min

[Wayne 962]

Originally Posted by manbridge 74

Clarification: the one pictured above is inverted and needs to be flipped....

Thanks for the thought Jeff, but they were installed from the factory in the "upside-down" configuration. This one is pretty much in the same configuration / orientation as the factory installed location.

-Wayne

[Mr Beau]

A flaky injector could easily be affected by heat which would help explain the 2 minute issue. One cylinder starts misfiring which then starts to throw other things off.

[Pete000]

Doesn't sound too bad, hows it driving?

[manbridge 74]

Originally Posted by Wayne 962

Thanks for the thought Jeff, but they were installed from the factory in the "upside-down" configuration. This one is pretty much in the same configuration / orientation as the factory installed location.

-Wayne

Ah yes, couldn’t make it out exactly from your pic I guess.

[Wayne 962]

Originally Posted by Mr Beau

A flaky injector could easily be affected by heat which would help explain the 2 minute issue. One cylinder starts misfiring which then starts to throw other things off.

That is a possibility. I think new injectors are in order if this problem doesn't go away...

-Wayne

[Wayne 962]

Originally Posted by Pete000

Doesn't sound too bad, hows it driving?

There's still a bunch of stuff disconnected and hanging down below, so it will probably be tomorrow until I can drive it...

-Wayne

[Zacman]

When the fuel rail was out, was it checked for rust? I got a 3.2 in a 914 that sat for 4 years, the "T" line to the side rails rusted almost to the point of being blocked. same crap in the return line to the tank.

[mike sampsel]

Sorry, this is not really any help ...

But if you are looking for some help "beating the snot out of it on the highway", I might be up for a trip

[Wayne 962]

Originally Posted by Zacman

When the fuel rail was out, was it checked for rust? I got a 3.2 in a 914 that sat for 4 years, the "T" line to the side rails rusted almost to the point of being blocked. same crap in the return line to the tank.

Yup, had the fuel rail cleaned along with the injectors...

-Wayne

[Wayne 962]

Originally Posted by Pete000

Doesn't sound too bad, hows it driving?

It's not exactly a good time to go out on the highways of Los Angeles to flog your Porsche. Today, I worked on the interior, and tomorrow I'll clean up the fuel lines and realign the windows. Then I'll see if we're still on lockdown. You'd hate to see me test this thing in a good ole' Los Angeles high speed chase (although that would be very noteworthy - most high speed chases involve pretty much very boring cars).

-Wayne

[ischmitz]

Originally Posted by Wayne 962

It's not exactly a good time to go out on the highways of Los Angeles to flog your Porsche. Today, I worked on the interior, and tomorrow I'll clean up the fuel lines and realign the windows. Then I'll see if we're still on lockdown. You'd hate to see me test this thing in a good ole' Los Angeles high speed chase (although that would be very noteworthy - most high speed chases involve pretty much very boring cars).

-Wayne

If you go make sure you’ll have a full tank of gas and a blowup doll in the passenger seat. It’ll make for more drama when the news choppers try to decipher if your passenger is voluntarily or involuntarily joining the run.....

[Mike Andrew]

Could be fodder for a new book. "101 Ways To Elude Police" by Wayne Dempsey.

[john walker's workshop]

Consider removing the firewall insulation for better airflow. Might run hot the way it is. Belt changes and timing checks would be easier, too.

[The_PS]

I have a 3.2 that is perfectly smooth cold, idles a little rough warm, but smooths out again around 1500 rpm.

I've now found several small vacuum leaks that two smoke tests didn't turn up. I see you don't have half the vacuum plumbing I have -- just to say that a cold smoke test at 1 psi is not that reliable.

[Wayne 962]

Originally Posted by john walker's workshop

Consider removing the firewall insulation for better airflow. Might run hot the way it is. Belt changes and timing checks would be easier, too.

The other 914 doesn't have that, and it's way too loud in the passenger compartment - I had to install the "helicopter style" headsets in there!

-Wayne

[Wayne 962]

Originally Posted by The_PS

I have a 3.2 that is perfectly smooth cold, idles a little rough warm, but smooths out again around 1500 rpm.

I've now found several small vacuum leaks that two smoke tests didn't turn up. I see you don't have half the vacuum plumbing I have -- just to say that a cold smoke test at 1 psi is not that reliable.

How did you finally find the vacuum leaks then?

-Wayne

[NoBozos]

Originally Posted by Wayne 962

It's not exactly a good time to go out on the highways of Los Angeles to flog your Porsche. Today, I worked on the interior, and tomorrow I'll clean up the fuel lines and realign the windows. Then I'll see if we're still on lockdown. You'd hate to see me test this thing in a good ole' Los Angeles high speed chase (although that would be very noteworthy - most high speed chases involve pretty much very boring cars).

-Wayne

Sure ain't no white Bronco...

[NoBozos]

Searched this post but didn't see it in the results, did you ever do a system fuel volumetric test to see if any cylinders are being starved? e.g. measuring each injector output while installed in the rails on the engine to include the "system".

Thought is potentially having good pressure but marginal flow that actually shuts off or starves a cylinder when it drops off the warm up RPM. This is based on your observations of a left/right difference after the car kicks down.

[The_PS]

Originally Posted by Wayne 962

How did you finally find the vacuum leaks then?

Poking and prodding ugly looking fittings. Looks like you only have the fuel pressure regulator and damper hooked up? No crankcase breather? I'd recommend testing the regulator and damper with a hand vacuum and then hooking up a vacuum gauge on the intake. (That's what I'm going to do this weekend.)

[cabmandone]

Am I the only one who finds it odd that cylinder 4 is running 30-40 degrees hotter than the other 5? When I get time I'm going to have to fire up my car and take some readings. I don't recall any of mine being that far apart.

Edit: You mention a few times early on that you measured temps and "they were all fairly even" (post 88, page 5). I haven't come across a post yet where you have temps. Just seems odd to me that the one is a good bit higher than the other five when the other five are all within 10 degrees.