Nick5545

If you have seen my previous threads you'll see I've had nothing but bother since taking my engine out to replace oil control ring seals.


The car runs now, when it wants to start. Some things I have done which haven't been adjusted for in the map

- upgraded fuel pump
- rewire of fuel pump to battery located in the rear

My issues starting are it will sort of crank and crank with the odd sound like it wants to start, if it does catch it almost sounds like its only on one rotor then the other sounds like it comes in and out. When you're cranking it whilst its still warm the engine will do some pretty decent backfires, im assuming its just dumping fuel into a hot exhaust?
When it does start the idle rockets to about 2.5k then settles down after about 10 seconds to around 1k.

When I de flood the engine after an unsuccessful crank there is A LOT of fuel vapour coming out, and when it does start it looks like it is massively over fuelling.

The car is running a power fc. Is there any way to change the cranking mixture on it? I read somewhere on this forum that excessive ignition advance could cause trouble starting and flooding issues.

Is it worth me doing a hard reset on the power fc? The power fc came with an R Magic tune on it.

Car has new coils, plugs and ht leads too.

billyboy

How big is the "upgraded" pump and is the reg still stock?

Nick5545

Its 350lph and the fpr is a Sard unit.

DaleClark

iTrader: (55)

There was a thread recently, someone ran that fuel pump with a stock FPR and it was running crazy high fuel pressure. You need to set your base fuel pressure. It should be the stock pressure so the shop manual's recommendations are correct. Use the shop manual to check it and adjust it down if its too high.

Dale

Nick5545

Its right around 30psi when the pump primes, I haven't checked what it goes to when I'm cranking but I'll set a camera or something to watch to the gauge I've put on the fpr.

The car is like a smoke machine now. The reason I took it apart to replace the oil control ring seals was it would smoke at idle and more when it was warm but clear up under load - ended up being the seals.

Now its just constant greyish looking smoke that gets worse when it revs, wondering if I've done something wrong when reassembling and haven't caught it...

DaveW

Grayish smoke is a sign of running WAY too rich - I'm guessing the fuel pressure, as you mentioned, is, in fact, the main issue.

Nick5545

I thought was could be a potential sign of running rich but wasn't sure. The car just has a crappy narrowband on it at the moment but it does just sit right at the max of rich and doesn't move from it so thats probably saying something.

The car is running a power fc and when I took it to get tuned, which is the reason why it had to come back apart again, the tuner did say that the map looks 'aggressive' and basically like 'a drag map' were his words. The power fc is an R magic tuned one so I'm wondering if I did a reset on it would it reset back to the base map or would it reset back to the r magic map that must have been on it at some point? Is there any way of altering the amount of fuel it puts in using the commander in order to get it to run at least vaguely ok?

I'm going to do some further investigating tomorrow so will update this thread once I've done that.

gdub29e

iTrader: (16)

https://www.rx7club.com/3rd-generati...needed-841706/


This is a great place to start. I would also look in the power fc sub forum. There’s allot of info on that ecu.

~ GW

DaleClark

iTrader: (55)

Yeah you are fire hosing fuel into that engine.

What mods are on the car?

What did you change during the rebuild process?

Dale

billyboy

A bit of a pain, unless the original pump was totally rooted, isolating those two items you've changed back to that original set up, should tell you if something mechanical is amiss. Even if there's whatever an aggressive drag map means on twins(?), it's hardly going to matter at idle.

Nick5545

I had a look at fuel pressure it primes at about 40psi then cranks at about 45psi.

The set up is a bit weird its a single turbo with 1000cc primaries. I didn't change anything during the rebuild. All we did after the rebuild was put a new engine loom on, do the fuel pump rewire to the battery in the rear and give it some new ht leads.

I never checked fuel pressure beforehand so I don't have any reference to what it was prior to wiring the pump direct to the battery.

gdub29e Thanks for that link too, Iooks great I'll have a good read of it.

DaleClark

iTrader: (55)

So you should have started with the 1000cc primaries....

Do you have the PFC set up for those primaries? If not it thinks you have stock 550cc primaries and you are pouring fuel in.

Dale

Nick5545

As far as set up goes when you look in the power fc it does say pr 1000cc ...

Any other adjustments past that have not been made though