So i just put 75 hp DDP injectors in my 89. And now if i let off the throttle it hits idle and starts to lope... I asked my bud in town what it was doing and he said that when the fuel entering the cylinder exceeds 16psi it starts to lope. Is this true and is it a bad thing or a bad a** thing? There are no leaks in or on the injectors or the injector lines so its not air in the fuel. I will try and get a video of it this afternoon.

 

It sounds like he knows what he's talkin about but I can't say for sure cuz I'm not really familiar with the first gens. With new injectors and stock lift pump you could be pushing it to the limit with bigger injectors so it's probably having a tough time keepin them fueled. I'm guessin so don't take my word for it.

 

So if i got a bigger lift pump it would help me to get the full power of the injectors?

 

Not necessarily "bigger", but a better lift pump. Such as an AirDog or FASS system that can move fuel from your tank to your injection pump more effectively. Now, I don't know if FASS makes a compatible system for the first gens but I do know that an ADII can be used for them. I believe using onr for a 2nd gen 12valve will work just some grinding/modifying is needed so it can fit the VE. I know there are some lift pumps that you can mount to the engine and run off the belt but I'm not educated enough on them to tell you much more.

As for getting full power, I'm pretty sure you're injectors are doing their job perfectly. Just know that if you're constantly hot-rodding around your lift pump will fail and in time so will your injection pump. I would higly recomend getting a fuel pressure gauge to see what you're running at idle and WOT to be safe, then take it from there. Good luck man

O do post the vid, I'm a huge fan of the first gens

 

whats your idle at? did your tamper with injection pump at all?

 

I got a Denny T stage 2 pin and turned the star wheel 2 turns but no smoke screw and no idle

Ill try and do a vid in a bit

 

my truck has been doing the same thing but mine i was told by the local diesel shop is caused because with new injectors you usually have to adjust the idle a bit. and he also told me to bump the timing 1/8 of an inch and that will help too

 

We at FASS have systems for the First Gen's up to 150 GPH.

 

Gov spring, put a 3200 rpm in it and it'll probably stop. Mine would hit idle hard, can't recall it loping but it was all after I turned the pump up.


Sent from my iPhone using Tapatalk

 

Cow pies.