Engine/Transmission (1994 - 1998) 370s. Good & Bad.

[Jeff H]

I got my 370 injectors installed. The installation went pretty good. My test drive was hly sht. 34 psi of boost at 3/4 throttle and still climbing like a rocket. I did not max it out. Not use to such a rush My egt's climb just as fast too. Going down the road it moves with such ease.

Well the part I was worried about was my rough running with the stock injectors. That low end to about 1300 rpm. Now with the 370's in it bucks the truck pretty hard too the point you could scramble eggs. Its only on light throttle puttin around in 4th. Sometimes in 3rd. If I keep it above 1300 rpm Its just fine. My suspisions were were always with the injection pump. Sorta thinking that it may be out of calibration.

I'm gonna keep them in for a little while. If the bucking gets annoying They are gonna have to come out.

Oh one other thing about the 370 injector. When engine is running in neutral. When I rev it to 1500 on up its not as smooth anymore. Its really slight though barely noticeable. Just wondering if thats common.

 

[Jim Fulmer]

Jeff do you have a Gov Spring kit in your truck,it's not listed? Your pump is fine, the gov springs don't know what to do at that point, there saying do I fuel or not, if you get off the throttle the bucking stops, if you get on it it stops and if you will notice the idle is a little rougher (slightly) with the 370's that is common and what you are feeling is the bucking when you increase the idle to 1400 or so. Look at my signature, I have the stumble too and I've done all I can do with adjustments and all Piers can think of except some special stuff. He is letting me try some different ideas out by me doing some R&D as it seems I have one of the unusual pumps. If I/We figure it out I'll post the results, till then you have to either keep it above 1300 and live with it or take the injectors out..... mine are staying it!



Jim

 

[Jeff H]

Hi Jim.

No I don't have a spring kit. I had a reamanned pump installed in 98. Since then Its always been kinda rough running under light load and light throttle under 1300 rpm. If I step on it pretty good it will come out of it. With the 370's it really amplified the problem.

There must be a way to control the gov a little better. Reminds me of some Briggs & Straton engines. There gov would always overreact with no load. But will snap out of it when you put a load on them.

 

[Jim Fulmer]

Your sounds like mine, my truck had just ever so slight stumble prior to the injectors and you could high idle it at 1300 or so and it would feel a little out of balance, maybe the same person worked on our trucks

 

[Extreme1]

Delivery Valves!!!

I had the same problem when I installed my 215's. I put in a set of 181 valves and all was well.



Until I installed a set of 370's on Sunday. Now I need 191's because I have the same bucking back but at a different RPM (900-1300) than before.



Anyone have a set of 191's cheap?

 

[radixr]

Jeff H,



I fixed the same problem you have by backing off a click or two on the governor springs. Perhaps your remanned pump has 3K or 4K springs and your just weren't informed about it. In any case, I would try backing off one click and see if it helps.

 

[Deezul1]

Prolly gonna need delivery valves, at least 181s and as long as ya gotta buy em get 191s. Do a search, there has been a lot of info posted on this problem.

 

[Jeff H]

Well tell ya the truth. I don't know where to find the governor. I think at are next TDR meet in North Dakota. Maybe I will get some assistance. John E if yer out there?

Would backing off the star wheel help out any. Make it less sensitive?

Thanks again guys sorta puts me in the right direction for solving this.

 

[Deezul1]

The spring adjustments are directly under the fuel plate. Remove the plate and rotate the engine and you will see the adjustment nut come up. There 2 of them 180 deg apart. I bet its the delivery valves though, if in doubt call Piers.

 

[Jeff H]

My question about delivery valves is. With the 175 injectors it still ran rough.