Evo 1 project runs rough

[Shooty]

Hi everyone

My friend bought an Evo 1 a long time ago and decided to make it run lately. The car probably spend most of it's last years in a barn so it's going to be a long run to make it beautiful again!

The car is completely stock except for the fuel pump. The reason is simple, rust had eaten away the tank, sending unit, pump over time so it had a Bosch 044 installed on a temporary fuel cell

To makes things quick and simple, it runs so rough it sounds like it's not running on all fours. We played around with some fresh plugs and we also tried with a coil on plug setup but it still feels so wrong.

We called it for the night

I wanted to have some ideas from other members here just to brainstorm about this:

Could it be the pump being so big that it is overflowing the capacity of the stock fuel pressure regulator?

Maybe the injector are being dirty and they would need a good clean along with the replacement of the fuel filter?

Either way, thank you for checking this post out!

 

[steve]

Sadly, I don't think there is enough information here to make any suggestions.

I assume that when you replaced the tank and pump you flushed the rest of the fuel system, replaced the filter, cleaned the injectors?

Have you measured the fuel pressure at the rail?

What ECU is it running. I'm guessing from the time period the EVO I (1992) it could have all the capacitor leakage issues that plagued the 1G DSM's. Have you made a datalogging cable and tried to log it to see what the ECU things is going on?

Since you made changes to the ignition did you check the spark and see a problem?

Just a few things offhand that might move the discussion along.

 

[Canadian_CD9A]

To answer your question - yes, the pump can overrun the stock regulator, and an aftermarket FPR is a good thing to have on a modified Evo 1.

I would suggest a total service of the fuel system, though. Clean out all of the old fuel, clean the fuel injectors (and replace the seals), replace the filter, and make sure the pickup sock isn’t filthy. Do a boost leak test to make sure that it’s not allowing extra air into the system, check the ECU capacitors, and then re-examine the stock ignition system.