So, i just got my FD out from storage. Its a 94 mod with 32k miles on the click, completly original.

When i parked it in october last year it was working perfectly.

So when i picked it up, i pulled the fuel relay to crank it a bit before starting it to make sure the bearings get lubed at low rpms. Put the fuel relay back in and it starts after some cranking, spitting smoke and all.

It runns perfectly, and i can get it up to 4-5k without issues (not tired higher).
But when i put the throttle past 40-50% it boggs down and hessitates. This happends from about 2k rpm and upwards. Untill i reach 2k it wont bog on full throttle even.

Anyone got some tips on what to start looking for first?

 

bad gas?

 

I left it with a full tank of 98 octane. But would not bad gas stumble in the entire range? Its no problem getting it to redline ss log as im not over 50% throttle?

 

I am wondering if the TPS is going bad.

 

Check the tps. I had a similar issue.

 

A local rotary head said he thought it could be the secodnary injectors that are gone bad. since it seem its only load dependent.

- Can rev to 7000k while drivng without problem if i take it slow
- Can put it in neutral and rev to 7000k with the throttle to the floor without problems
- If i have load on it, it will start hessitate around 2k with throttle more than 30-40%

So i will try and unplug the secondarys one at the time and see if there is a change or not.

Any tips on how to check the TPS for error?

 

TPS is a potentiometer. When they go bad it usually goes bad on a spot intermittently then it becomes apparent.

If it take just disconnecting an injector to check, do that first.

Then worst case you can pick up/borrow a working/good TPS and try.

 

I would run a can of BG44K injector cleaner in your gas tank. It will clean the injectors, maybe solve your problem.

 

Went over all grounds and cleaned them after reading about hessitation and stunbling in threads here, and that solved the problem

 

Thanks for reporting back. Which ground connections have you cleaned? Care to share with a photo?

 

The one on top of the engine, from the back og the intake manifold to the firewall, and the one on the driver side shock tower, under the main fuse box.

They are described here:
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/hyper-grounding-system-15-rwhp-127905/page2/#post10022821