MPFI conversion

[Ryan Krizan]

Working on converting my 99 tahoe to mpfi injection. After I installed the new MPFI unit, I noticed the injectors do not seat well, at least not all of them. Most of them seat, and will stay in place, but a few of them, most notable cylinders 1 and 3, will pop loose with the slightest of force. I can easily push them up from the intake side.

Is this normal? Everything looks fine to me. I'm not sure what's going on.

 

[Big Mama]

Welcome from Virginia Ryan I’m no help with this one but others will chime in soon.

 

[OR VietVet]

Welcome to the forum from Oregon.

Did you try switching injectors with another spot to see if the problem follows the injector?

 

[Ryan Krizan]

Welcome to the forum from Oregon.

Did you try switching injectors with another spot to see if the problem follows the injector?

I did try that, and the swapped lifters still had issues in those locations. What I ended up doing was braiding copper wire and slide it in behind the plastic locking collar to give them more pressure against the walls of the lower intake. That locked them in nice and tight.

Redneck enginuity

 

[OR VietVet]

Good idea but are all the injectors new and the intake new? If so then you should not have to do that. You may have to spring for new injectors because it sounds like the intake is ok to hold them.

 

[Ryan Krizan]

It's a brand new AC Delco MPFI conversion. The lower is the original manifold. Plenty of shoulder. I think it's just the locking tabs on the injectors that aren't well designed.

 

[OR VietVet]

I agree. Good luck.

Pics of install please.

 

[Ryan Krizan]

Sure I can take some pictures. I’ll take some later today when I have some tims

 

[exp500]

Are the holes clean? Sometimes carbon buildup on the ridges keeps it from locking. Bottle brush in drill works. I think thats in the manual too.

 

[Ryan Krizan]

Are the holes clean? Sometimes carbon buildup on the ridges keeps it from locking. Bottle brush in drill works. I think thats in the manual too.

Oh yea, they are spotless. I wouldn't use a drill with a bottle brush though. I used a bottle brush by hand power only. That's just my personal opinion.