My 3500 UIM install(finally!)

[SE'sarecool2]

OK, so I've finally done it. Yeah I know others have already done it but I've been wanting to do this for over a year now(and have had numerous financial setbacks) - and I might be the only one doing this on a stock tune PCM... for now at least... the demise of DHP's Powertuner has made me re-think my tuning options. For now, it runs great(even with leaking injectors). It was quite an ordeal though, not what I would call easy but SO WORTH IT! I'll post up more pics tomorrow, for now enjoy this one and feel free to make any comments/suggestions you might have.






P.S. Ben, I had to do a significant amount more grinding to clear the FPR; nor sure what your test fit motor was but it was way off when I first tried it.

[IsaacHayes]

It helps if you loosen the bolts holding down the fuel rails, then push the fuel rails away from the neck, then bolt it down to hold it there. I did that with fresh o-rings on the injectors so they moved easy. That gave me a lot more room. I also loosened the FPR and tilted it in the rail away a little bit, then re-bent the metal fuel line so that the bracket that holds them down would bolt flush again.

I'm running OBD1(.5) so mine is un-tuned... I went from small ports to 3400 lower and 3500 upper at once.

How does it feel different?

[SappySE107]

Im surprised you had to grind, as I had a LOT of room once I pulled the harness off and tried again. Was my grinding in the right location for your setup? I don't know why it would matter but I was using a 98 3400 with 00 3400 heads and 99 3400 lower, 99 injectors and 99 FPR.

Loosening the injector rail hold down bolts (2) and pushing it forward (in a FWD car) is what I did as well. If its all the way back, then it will not clear at all. Loosening the FPR and tilting it as far as it goes sounds like a good idea as well. I will add these 2 things to my list. What did you do about the vacuum lines and the CCP?

[IsaacHayes]

If you are referring to me, on a 94 3100 the CCP line is still stock which shares the vacuum from the PCV. Only lines I addressed was the vacuumball/trans-modulator line and FPR.

[SappySE107]

No, but I can use all the info possible

[SE'sarecool2]

Doh! I didn't even touch the injector rail hold-down bolts, Ben. Great, another reason to rip it apart again! I'm going to have to take the plenum back off when I replace the injectors, anyway. The motor shudders frequently at highway speeds and my MPG is in the toilet... I've been thinking it was a fueling issue but became more sure when I went to try and tilt the FPR during the install. When I went to relieve the fuel pressure in the rail... there was none. I'm fairly certain one or more injectors are leaking. BTW, Isaac, I'm also still running with the stock SE exhaust too... to answer your question it feels stronger above 3500 RPM. When its not shuddering from the bad injectors it really likes to rev... I can't wait to uncork the exhaust and get the PCM tuned and feel the full effect of the swap. Then its 3500 heads/LIM and a cam!

[SappySE107]

Do you smell gas? When did you try to relieve the fuel pressure?

[SE'sarecool2]

No, I didn't smell gas. But it was barely 30 degrees outside & very windy so I couldn't smell much of anything. I'm not sure what you mean when I tried to relieve the fuel pressure... when I realized the UIM wouldn't fit I remembered reading about rotating/tilting the FPR for more clearance. Then I pressed the shrader valve on the end of the fuel rail. Nothing happened. When I removed the regulator from the other end of the rail fuel dribbled out slowly. I tilted it a little bit, tweaked the hard line so the regulator would fit back on the rail and snugged the bolt. The car sat overnight before I started installing the manifold but I think there should have been a lot more pressure still in the rail.

[IsaacHayes]

It could be the FPR leaking down too or leaking into the vacuum line. My rail holds pressure for ever it seems.

[SE'sarecool2]

More pics.
The 3500 MAP sensor pigtail.

[SappySE107]

How much was that? I can get a harness adapter to go from the old type to the new type and not have to solder/crimp anything.

[SE'sarecool2]

The connector I got from EFI Connection; thanks to Isaac for finding this source. It was too cold to go junkyard hunting for it. Slight modification is needed to make it plug in properly though. There are two index ribs inside the connector that must be removed.

[SE'sarecool2]

How much was that? I can get a harness adapter to go from the old type to the new type and not have to solder/crimp anything.

It was kinda expensive(about $25)but I had a connection(my brother works at a GMC/Pontiac dealer)

[SE'sarecool2]

Another hurdle was moving the p/s pump out of the way so the injector harness could go under the fuel rail; otherwise it would've been pinched between the UIM & the p/s reservior

[SE'sarecool2]

Finished!