So I've rebuilt(headgaskets/timing belt sys) this 4r 3vze 95 and almost everything seems to have gone well. Compression was at 190, it drives and all CELs are off. What I can't figure out is why it has no acceleration. When put into gear it shifts hard, then when driving it takes a very long time to get up to 50mph and simply can't get above 70. It seems as if there is no correlation between gas and acceleration. I can floor it and have the rpms at 3500+ and it will accelerate at the same rate as 2000. If someone could give me a direction to look that would be great.

The only things I can think of is timing or a vacuum leak. My buddy set the timing tho and it seems fine and I've sprayed around the engine with starter fluid and have heard no reaction.

Thanks in advance guys. I wouldn't have gotten this far in the rebuild without these forums.

 

Just a few ideas, double check vacuum routing especially to the egr, make sure the flapper in the vfram is not binding, check the fuel filter and fuel pressure, is the cold start injector shutting off when warm? and use a vacuum gauge to see if you're getting around 20 or more inches of steady vacuum at idle, different fluctuations can be used to diagnose different issue. A vacuum guage is an underrated diagnosis tool.

 

Thanks for the quick response. so I checked the vacuum with a rented auto zone gauge and it definitely went down quickly. I checked with starting fluid sprayed around but I'll try again. Any other ideas about how to locate the source of the leak? The egr was deleted and the vafm was replaced with a junkyard one with no change. It seems like checking the fuel pressure will be a bit of a hassle, I'll get a kit for it tomorrow if possible. I did run some seafoam through the tank, with no change. Wouldn't that maybe clean the filter if it was partially clogged?

 

There is a link to help use the vacuum guage...http://www.imperialclub.com/Repair/F...auge/index.htm

I'd suggest changing the fuel filter if you don't know how old it is, even if it is not causing the issue. It's not a hard job but is very dangerous if you don't know what you're doing.

 

What did he set it to? (The correct number is on a sticker under the hood.) Did he jumper TE1 to E1 first?

If the timing is off, you should get the symptoms you describe.