problems getting 13b running after rebuild

[BarryB]

Hi everyone, this is my first post here, wish I had found this forum months ago!!:mad:
Anyhoo, I have a \'88 FC non-turbo and I lost compression on the rear rotor some months ago and have stripped the engine down and found a broken apex seal. The car has been back together nearly three months now but I cannot get her running properly!
Its a pig to start, mostly just flooding, but when it does start it runs very rough and lumpy at low rpm, wont idle at all. Seems fine at 3k and above.
I\'m sure its the rear rotor thats the problem still. I can start it and run on the front rotor alone fairly well, but not the other way around. There\'s fuel, there\'s sparks and they are at the right time.
I\'m worried that I have broken something during the rebuild, a vacuun pipe or wire.
Any suggestions? how to dianose the problem??
TIA

[Sean]

I had the same probs and all it turned out to be was a hole in the air intake pipe, because it was after the airflow meter it made it run sick as a pig on idle and eventually stall but when it was being revved it seemed fine

[BarryB]

thanks for the suggestion, I\'ve checked it and its ok.
Besides it wouldn\'t explain the difference between front and rear rotors. I\'m trying to think of some way air could leak in to one rotor only

[bill shurvinton]

I would do a compression check. What you are describing sounds very much how my engine behaved BEFORE its rebuild.

At least it would remove 1 possibility

Bill

[Sean]

Originally posted by bill shurvinton
I would do a compression check. What you are describing sounds very much how my engine behaved BEFORE its rebuild.

At least it would remove 1 possibility

Bill

This is the best advice! This is why my engine is sat on my patio waiting for Pip to come pick it up for me, and that I have to cycle to work at midnight in the pissing rain!!!! But I refuse to sell her cause I know that it will all be worth while in the end:cool

[BarryB]

is it possible to check the compression without resorting to that very flash and expensive test kit that the dealers would use?

[Wobbz]

What sorta rx you got sean?

[Glenn Butcher]

Hi Barry,

You can use a piston engine comp. tester - but the readings won\'t be accurate.

What you will be looking for is that the comp. is the same/similar per chamber for the front and rear rotors.

Just take the two top (trailing) plugs out.

You can also do a test by ear, by taking the two trailing plugs out - disconnecting the coils and turn it over.  They should all sound consistent i.e. psh psh psh psh psh psh


What was replaced in the engine?  was the rotor housing damaged and then replaced after the original apex seal let go?

[BarryB]

Hi Glenn,

Thanks for the reply, I have checked the compression by ear as you described and there is no discernable difference in the sound from the two rotors.

All the apex and side seals were replaced on the rear rotor, the housing was NOT replaced, there is some marking where bits of broken apex seal impacted but after discussion with the main man at Hurley engineering (and due to not having the cash for a replacement) it was considered that the effects ot the scoring/pitting would be negligable. None of the damage was on the compression/combustion part of the housing.

I know this is not an ideal situation, but after spending nearly £4.5k in the last three years on exhaust and engine I\'m not able to put much more money into the car.

The more I look into what is wrong the more I\'m convinced its not the engine internals. However, I appeciate people going over all possibilities to ensure I haven\'t overlooked something.

Barry

[Wobbz]

Possibly a damaged ecu?

Have you changed your plugs/leads?

Proper connections for wiring? (ie. wires leading to/from the engine, when you removed/installed it).

Intake isnt blocked with anything? (airbox)...

injectors are clogged/damaged?

Those are just generic things which could be the problem....

[BarryB]

Hi

damaged ecu? difficult to tell without a known working one to swap it with to see.

plugs and leads are not new but have all been checked out
there is a spark at each plug

I took lots of pictures with a digital camera during disassembly to help when it came to reassembly to ensure I got the wiring and plumbing right

injectors have all been checked and function ok, the wiring has been checked back to the ecu
btw, which injectors supply fuel when idling?

It may be an air block but it must be specific to the rear rotor because the engine will run on the front one but not the rear.

Barry

[Wobbz]

Don\'t they only have 2 injectors :confused:

One in each chamber?  (im a rotary newbie... more of a piston man )

[bill shurvinton]

I used a regular compression tester on my engine and was pleased to note that my readings were close enough to those from a factory tester to at least prove the engine was not right.

A compression test is only #15-20 at a specialists, so worth doing. If you have put new seals on an old housing it is likely to idle like a dog for the first few hundred miles anyway.

Get that checked. I spent 3 months trying to trace a fuel, spark or air leak problem and it was a worn engine all along. You have rebuilt that part so that is the first thing you have to prove is right

Other than that you have to just check every connection to see if there is an air leak.

Bill

[BarryB]

Wobbz,

They have four injectors, two per rotor. They inject fuel into the inlet manifold, one right in the inlet port and one further up the manifold.

Barry

[Wobbz]

Ahhh thats right.... my brothers mate runs like the standard injectors and 2x bosch (?) 1600cc items

~350rwhp @ 15 psi... (from what they tell me).... fully built engine from R-Magic... HKS to4r.... its a very nice ride... too bad I haven\'t been in it yet :mad: