I have an 89 CRX Si (first Honda wooohooo!!); the seller told me he installed DSM injectors. There was no tune or anything to make up for it. Since I was getting lowish gas mileage, I thought it was probably true, so I ordered a chipped ECU with a basemap for the injectors (from Xenocron).

Anyhow, that arrived today, so I installed it. When I started the car up, the idle varied from ~500-1500. So, my question is:

1) Do I probably only have stock injectors?
2) What's the best way to verify which injectors I have?

Then, once I know about injectors, I'll be on the trail of the mpg...

Thanks everyone

 

google what each looks like. there both low impedance tho so u cant test the ohms. i believe dsms are blue up top

 

Is your crx turbo/SC? Or built? I have some stock injectors if you need them. If your car is stock or has regular bolt ons remove the dsm injectors and get stock ones.check what color the top of the injectors are, dsm 450s should be blue. If they are black you might have something else.

 

Top: DSM 450cc "blue tops" (some are black)

Bottom: Honda Injectors

 

Thanks for the comparison.

The engine is essentially stock. I'm really inclined to think I have the stock injectors; if not, I might be interested in yours.

Hopefully I get home during daylight tonight, and can get a decent look at them. Otherwise I ought to find a less blue flashlight for color recognition.

 

Don't solely rely on color reference.. some dsm 450's have black tops just like Honda.

 

Basemaps often cause erratic idle, doesn't necessarily mean anything is wrong. But given your low MPG, you probably need a good tune up at least.

 

clean the iacv?

 

Actually, i've already cleaned the iacv *very* throughly, which improved the idle significantly. I swapped the stock ECU back in, and it idles quite nicely as before (I should have known they were stock injectors - ran to smooth to be 450s without tune, probably).
I was initially thinking I had the black top DSMs, which I was aware of.

Re: tuneup, that's probably what I ought to do. I rescued the car after it had been sitting for some time, so I'm trying to find and fix issues as I go. Also I'll probably grab the multi-meter and check the o2 sensors just for curiosities' sake (I've gotta smog it, being in CA).

 

Before you do the o2 sensor, do the tune up. You can foul new sensors if it's not running right. I'm talking about spark plugs, wires, cap, rotor, air filter, fuel filter, oil and filter, pcv valve, check timing, and a new timing belt is probably a good idea.

 

check your fuel pressure too.

 

I can assure you that you don't have bigger than stock Injectors. Your vehicle (if it would even idle to begin with) would flood out as soon as you touched the gas at worst; at best wouldn't be remotely drivable.

There is WAY too many variables to say what the problem is because of "poor gas milage"... Also, you never said what "lowish" gas milage is in the first place.

 

Thanks for the perspective - I knew they didn't run well, but didn't realizeNhow bad it would be.

Anyhow, I'm getting mid-upper 20s for mpg (haven't driven it enough to be sure). But I realized today when getting ready to check ignition timing that I had set the cam timing off the wrong mark when I changed the timing belt *facepalm*
Hopefully fixing that will help with fuel economy

 

Well... there is your problem pretty much "garunteeeed"!