New motor, cannot pass 3000 RPMs?

Well, I just got my chip today, the car is running excellent! The only issue that it seems to have is that for some reason it will not go past 3000 RPMs? Could it be that my fuel pump is maxxed out? It is a stock 305 TPI fuel pump. The new 350 is pushing 300HP and running on a set of LT1 injectors that I got from formula (Thanks again formula!). There was no rev limiter available on the 3rd gens that maybe is kicking in while I drive? I am stumped here... Any input on this problem would be great. I have a feeling I may need a high output fuel pump though... Oh yeah, the car does not do anything strange (ie. backfire, etc.) when it hits 3k RPM, it just sounds like it's bogging down and won't go over 80 MPH. Thanks guys!

Yeah does sound like you need a matching fuel pump..

Sorry guys, I figured it out after I thought about it a sec. I didn't have the TV cable adjusted correctly. :banghead: Got it working now, but still being cautious with the new motor... finally worked all the bugs out! BTW thanks for the reply Rally.

good to hear you figured it out

good to hear you figured it out

Thanks :)

Sadly I have now noticed that the tranny slips a bit when shifting from 2-3, and does not shift to 4th til about 90-100 MPH? I only set the cable to the stock position. Would pulling the plastic clip thing more toward the throttle body help these issues any? I know I will need a new trans at some point, but I am hoping it will hang on til I get more money and can actually afford one.

After a few years those plastic lock clips don't work like they did new, so the "push cable all the way back, then slowly open the throttle so it will set itself" is almost out the window. I do that to get in the ballpark with it then adjust forward (softer shift) or back (harder) one tab at a time by hand.

You may want to check the modulator out itself on the trans too for any leaks.

After a few years those plastic lock clips don't work like they did new, so the "push cable all the way back, then slowly open the throttle so it will set itself" is almost out the window. I do that to get in the ballpark with it then adjust forward (softer shift) or back (harder) one tab at a time by hand.

You may want to check the modulator out itself on the trans too for any leaks.

Thanks. I'll give that a try.

No problem on the injectors and glad to hear you got it running correctly now.

John

No problem on the injectors and glad to hear you got it running correctly now.

John

Yeah, it's not quite as fast as I was hoping for, but I will probably post some vids/pics some time.

Don't stock LT1 injectors have a higher puond rating then the 22lb max out of stock TPI ECMs? I thought they were around 24 lbs?

24.9 to be exact. Thats for 94 - 96 . The 92 - 93 LT1's used 22 lb injectors.

so wouldn't that require tuning the ECM?

Yes, or else the car would be running rich. Although, the ecm is said to use the O2 reference to change the band width pulse of the injectors. So it may be able to make up for the larger injectors without a tune but you would most likely get better results from a tune.

That's what I thought and we are talking about the rather inferior design of the '85 TPI ECM. So I'm wondering if this in fact is hurting him.

Oh, and speaking of which, the O2 on mine was burnt through on the headers, didn't even throw a damn code, so I wouldn't place much faith in that. '85 as well.

Well, when I did this swap I bought all new sensors and everything, so I know that is all good. The car would not stay running with the stock 305 TPI PROM, so I HAD to get it tuned for the setup I have. I think the tune is about as good as it will get. I just meant it is not a whole lot better (that I notice) than the 305 was. Also, I have an AFPR so I can set my fuel pressure to correct any lean/rich issues. I do believe that my tranny is partly to blame for the speed thing though. I will have to be looking for some money to save for a new one soon I think. Also, I am running my timing a bit too far advanced and I believe the ECM is setting it back a few degrees due to knock. I will be dropping that back a couple degrees the next time I drive it. Oh yeah, will pulling the TV cable back away from the TB 1 or 2 clicks make my 2-3 shift not slip as much? Right now it is slipping for about 1-1.5 seconds before it grabs under light throttle.

Well, if the 1-2 shift is correct then no, setting it back another notch isn't going to really help out 2-3, and consequently will make the 1-2 shift harder and push the limits of the valve. You probably have a burnt up clutch band or weak servo.

did you check the vacuum line for breaks, cracks or signs of fluid in it?

on the injectors I was just tickeling my intella-bone and getting a little educated about the LT1's in a TPI.

Could it by any chance be my torque converter? Just not locking up til I get the revs up? Anyone know the stall speed on an 85 700R4?

I'd really be looking into the vacuum modulator, honestly. And, most replacement ones now are a one size fits all with a adjustment screw for the right application.

I wanna say the stall speed is 2,800, don't quote me tho, but sounds close. .