Weber Carb Swap on 89 Nissan D21

[Burningtime66]

I have an 89 Nissan d21 that I have done a Weber carb swap on. The old TBI was trash and not working so went ahead and switched it out with carb after reading that this is a great fix for these trucks. However, after I changed out the TBI with the carb I was unable to get the truck to rev over 2000 rpm. I have since found the answer to that problem by checking codes and found out that the MAF sensor sill needed to be hooked up. So, now I am able to rev the truck up normal and even drive it down the road some at this point. However, when I get to a certain speed or gear while driving it starts to sputter and back fire a little. I just have the MAF sensor connected and laying in the engine bay. Would this issue still be associated with the MAF sensor? If so does anyone have any thoughts on how to go about fixing the issue or maybe even getting rid of the sensor completely. Thanks in advance for any and all replies.

[datzenmike]

Get the distributor and the oil pump drive spindle below it from an '83-'86 720 Z24 engine. Might as well get the two coils also. Now your ignition is stand alone and doesn't require anything from the D21 but power.

 

I assume you have put a 3 PSI fuel pump on or a regulator to restrict the EFI pump????

[Burningtime66]

Yes I have

[Burningtime66]

So with the MAF sensor would that still need to be attached, if so where because on the 89 TBI it was screwed into the side of it.

[datzenmike]

The MAF reads the volume of air entering the engine. How is that done with a carburetor?

 

Anyway all the sensors help to calculate the mixture and the ignition timing. With a proper mechanical distributor all that becomes moot. You would have a non EFI Z24 when done.

[Burningtime66]

That is what I was thinking. I have watched some vids with this kind of swap with out changing any of that and it ran fine. So I guess my question is why would the 89 not run basically without that sensor but others will even though they have the sensor as well. More "intelligent" ecu in the 89?

[Burningtime66]

So basically putting that Mechanical distributor would bypass the need for the sensor so then the truck should run as it should.

[Burningtime66]

Thank you very much for the info by the way it is very helpful. Basically have ran into a brick wall trying to find out what to do with this thing.

[datzenmike]

18 minutes ago, Burningtime66 said:

So basically putting that Mechanical distributor would bypass the need for the sensor so then the truck should run as it should.

 

The Z24i that you had/have has a CAS (crank angle sensor) that tells the EFI's computer where the crankshaft is. Somehow a spark signal is generated and adjusted for timing depending on sensor input such as throttle position and air flow. How can this be accurately done if the MAF is not connected to the air flow through the carburetor you put on?  Better to complete the EFI deletion and run this Z24i as a Z24.

 

You'll need a Z24 distributor and the drive spindle below it. The CAS drive spindle is splined and won't work with the older distributors. Best get the older coils too.

[Burningtime66]

Alright thank you very much for the help

[Burningtime66]

How would you go about putting the old distributor on the newer engine it has different mounting. Is there an adapter of some sort that would work? Any suggestions?