Bogging/backfire at low rpms
 

Hello. I have a 98 crv that I just rebuilt the head on. Timing is on (checked it 3 times), compression checks out. The problem is it idles like poo, way too low after adjusting it, and between the 1-2.5k rpm marks, it has literally no power until it passes those rpms. Didn’t get a chance to plug a scanner but, I was on my way home from work and it started something new. Check engine light came on and now it’s also backfiring through the intake. Tried to set ignition timing but, it only runs semi okay with it advanced all the way +. Replaced the tps, replaced the timing belt, checked all grounds. Everything seems to be fine. Anyone have any suggestions? B20b non VTEC.

Also, I ordered a new o2 sensor & map sensor. Waiting on that to come in but, I don’t think those will be my problem.

Who rebuilt the head??

I did. Also had the head resurfaced..

Well, many times when something doesn't go right after one works on something,
It is usually what one worked on that needs to be checked

Not saying you did anything wrong but we need to check it.
It may need outside eyes to look at it
I know sometimes I see something and believe it right then I can't see where I went wrong.

Good luck

The most common cause for this problem is a weak fuel pump which cannot supply the volume of fuel needed for the injectors to produce a proper spray pattern or deliver the amount of fuel needed for engine acceleration. you might want to pressure check the system.

I would say that was right if the loss of power was consistent through out the rpm range.
Power output from the fuel pump should not change with respect to rpm of engine
Of course, I could be wrong. Have been many times.:eek:

Everything internal was done right and looked over by a mechanic before putting it back on. The thing that has me is, I got the car for literally nothing because it had a valve that was bent and I have no clue of the problems it had before hand. I’m thinking that’s were I’m at now with it. I’ll check the fuel pressure over the weekend. I though of the same thing with it being something to do with fuel, but as noted I also thought it wouldn’t run fine after high rpms. The map is arriving today so, I’m going to replace that along with lookin over the cat.

Map didn’t change anything. Connected the obd1 service port together and only got three quick flashes. Can’t seem to find that code.