Help needed 1993 rx7 FD bucking and backfiring

[proudlove]

So long story short decided to book it in for it's m.o.t few days ago and took it out for its first drive on the road in about 20 years thought I'd take it out early and drag the breaks to clear them up as replaced them all a year ago with a new set all around and started to get a bit scabby.

took the car out and properly babying it as engine is completely fresh apart from a few start ups to bleed system . After driving for a few minutes I realised if I pushed the car a tiny bit like went over about 10% throttle the car would bog down massively and start to backfire it was that bad on the way back I made the mistake of going down the bank and had to go back up it I couldn't take the car out of first to second with out it falling flat out it's face and sounding like a AK47 is behind me ended up going back up the hill around 3k rpm about 15 mph and the car wouldn't push past that without just bucking ans backfiring .

Could do with any sort of advice the car is completly bone stock 93 import apart from a cat delete at some point in it's life.

it's had a full engine rebuild with the rats nest fully replaced out for new solinoids and vacuum lines .

I've also replaced the fuel tank and pump/filter for new .

Tried with completly fresh sparks .

I've Smoke tested the system through the UIM from the line that goes to the master cylinder not found anything from that.

Any advice would be great , im so close to finally enjoying this car

 

[Project Tiger]

Coils? Are they tested and decent? Is there a certain orientation to the cables?

 

[proudlove]

Coils? Are they tested and decent? Is there a certain orientation to the cables?

Haven't tested the coils , I've got a spare OEM set so will test them as well . What do you mean by the orientation ? Like the lead and trailing order ?

 

[Project Tiger]

Haven't tested the coils , I've got a spare OEM set so will test them as well . What do you mean by the orientation ? Like the lead and trailing order ?

Yes, I'm not clued up on the ignition system but I'd imagine you'd have split timing for the plugs due to flame propagation speeds. It may be able to handle small volumes of fuel, perhaps the mixing is more homogenous at lower throttle angles and you have less "cold spots" or concentrated zones of HC in the chamber. Thus if they're swapped you may be firing the trailing first and the leading last, causing a lot of the fuel to get chucked into the exhaust and booooom

 

[Jit]

20 years off the road, id check fuel tank. if its rusty and pump is covered in rust then thats your culprit

 

[proudlove]

20 years off the road, id check fuel tank. if its rusty and pump is covered in rust then thats your culprit

All ready replaced fuel tank / pump and fuel filter and lines for new so should be able to rule that out

 

[proudlove]

Yes, I'm not clued up on the ignition system but I'd imagine you'd have split timing for the plugs due to flame propagation speeds. It may be able to handle small volumes of fuel, perhaps the mixing is more homogenous at lower throttle angles and you have less "cold spots" or concentrated zones of HC in the chamber. Thus if they're swapped you may be firing the trailing first and the leading last, causing a lot of the fuel to get chucked into the exhaust and booooom

Checked the leads they are correct and tested the coils and within spec

 

[Temujin]

might be worth trying a smoke tester to check for vac leaks!

 

[proudlove]

might be worth trying a smoke tester to check for vac leaks!

Was the first thing I tested tbf ran it through the UIM from the master only area it was leaking from was the oil filler neck

 

[Temujin]

Have the injectors been flow tested?
What was the reason for rebuild?
Wonder whether the replacement of the rats nest has not been completed correctly

 

[jack.am]

MAP sensor

 

[proudlove]

MAP sensor

Is there a way to test the map sensor ?

 

[proudlove]

Have the injectors been flow tested?
What was the reason for rebuild?
Wonder whether the replacement of the rats nest has not been completed correctly

I semi tested/cleaned the injectors just to make sure they were working a while back but didn't flow test them just checked they weren't leaking and spaying as they should .
Car was imported in 2006 and blew up in 2006 with originally was I think jacket failer and sat for 20 years until I bought it . Engine was pretty much unusable apart from one of the rotors , had had the rats nest colour coded when It was rebuilt so have double checked they are correct.

 

[proudlove]

Also car idles fine a moves lovely under 3k couldn't believe how smooth it felt until i took it out properly onto the road and started backfiring tons and bucking . I plan on getting a boost gauge for it just to see that it's even making boost as it does feel a bit limp but I've never seen another rx7 or drove one so got nothing to go of with how it would feel