Hello all, before posting this thread i have been trouble shooting and searching countless threads with similar problems for over 2 weeks and have not found a solution. I am having a problem with my swap I recently performed. My car is a 92 civic si, the motor is a 2000 b18c-r using a 1999 usdm gsr harness. The problem I am having is around 2500 rpm the car shutters, backfires and Boggs completely out. Under a certain load on the motor the motor cuts/Boggs out as well and can not rev over 2700-3000 or above at any time. The car has only 1 check engine light that is a knock sensor which I have disabled through my s300. I have set timming with hondata and a timing light to the red mark 16 degrees btdc.
What I have done to trouble shoot is to check/calibrate the tps, replaced the distributor with a known functioning one, checked and even placed more engine and chassis grounds on the motor. It is currently open header and intake right now so no worries about a clogged cat. I have checked the tps and map sensor plugs to make sure they are not reversed. The the car idles and drives fine up until a certain load or rpm and then nothing. Any help would be appriciated

 

this really sounds like a bad map sensor.
Are you running a stock map sensor?
Do you have a diffent map sensor chosen in your s300?
Have you watched your map signal from your s300 in the tables?
If your getting a bad reading in the s300 check the wiring in to the map. 5v input, sensor ground input and 5v output. Check the readings with a multimeter.

 

I have looked at the values when I give it some gas it does move. If I remember correctly I think at idle it's at -22. I also did check the voltage going to it and had 5 volts but have not checked the out put voltage. Yes I am running the stock itr map with all of the default values with the itr base map. I did try the p30 map to see if it was a corrupt file but nothing changed.

 

Check the out put at the sensor I think the vac. Reading should be higher escpecially with a itr motor.

 

Is the timing perfect at the crank and dizzy?
At tdc the distributor rotor always points at the number one cylinder terminal.

 

Do you have a spare known working ECU or can borrow a friends OBD1 VTEC ecu? Even if its a stock P28 just to rule out any base map or ECU issues?

 

Yes I do have a virgin p28 that I could use

 

Check the thermostat ground for your wire harness.
Check for continuity from your chasis to that gound point. Should be infinite/continuous.
Also check your voltage at the distributor. Is your battery fully charged? If you don't have a multi meter now is the time to invest 50 dollars into one. They last you a lifetime.

 

Tried the virgin p28 and still have same issue, also tried different map sensor and is still doing the same thing. I have a voltage meter and will check the voltage on everything. The battery is brand new as well. When the car boggs out the intake makes a whistling noise.

 

Also thanks for the help so far guys

 

I checked the cam timing and everything looked perfect at the white tdc mark. I also checked the spark plugs and noticed that cylinder 1 and 4 had oil in them, I took off the valve cover and noticed the spark plug tubes do not have the gaskets around them or on the valve cover. Not sure if this would cause the problem but a new gasket is on order. I also checked the in and out voltage at the sensors and at the ecu and everything was in spec by the Honda.

 

I checked the thermostat ground and even sanded both contact points as well as the engine/chassis grounds. Voltage at the distributor was approximately 12v. Battery is fully charged. Problem still persist

 

If your spark plugs were soaked in oil that would cause a lot of problems fix that first and go from there.

 

When the gasket set arrives I'll post the results.

 

Had a similar problem before. After checking several different things I found a break in 2 of my spark plug wires. Hope this may help

 

I'll check I have brand new ngk plugs and wires with a Honda cap and rotor that was put on.

 

Replaced the valve cover gasket set and all spark plug tubes are staying dry now but the problem still persist. I checked the ohms of the coil and it was some what in spec, at tempature of 68 degrees it's supposed to be between 0.6 - 0.8 and it showed 0.9 at about 76 degrees. Between the secondary terminals it was in specs are 12.8 - 19.2 ohms, I was at 17.86 ohms. I also checked the icm everything checked normal, but the book says if everything thing checks normal replace the icm.

 

I did take the vacuum hose off the fuel pressure regulator and the throttle responce seemed to improve slightly (could be wishful thinking) While the car is parked i can press the gas pedal down about 40 percent until it boggs around 5000 rpm, if i go wot it boggs out way before 5000 rpm. I can only rev to around 5000 rpm while no load is on the engine, while driving i can not rev above 3000-3200. Again i have no codes and this is not like limp mode. I have a fuel pressure gauge and a icm ordered that will be here Monday.

 

Fuel pressure! And check the feed line from your fuel filter to fuel rail!

 

Will do Monday or Tuesday, the feed line is a brand new p75 line off an itr. Also I'm not sure if this is normal but the fuel pulsation damper screw sucks in towards the fuel rail when I give it gas and at idle it comes back out.

 

Solved the problem, my car was starving of gas and I think the fuel pulsation damper is the culprit. What I did to solve the problem is drilled a hole on the fuel rail fitting to get more gas in the rail. I made the hole align with the fuel feed banjo so I'm not having to send the fuel past the damper but it will still some what dampin the fuel. I have never heard of this problem before and wonder why this was a issue. My fuel set up consist of a stock civic fuel pump, brand new Honda filter, and a brand itr feed line. The crush washers and everything are placed correctly on the banjo fittings.