having problems with my 88 rex

[88crxsi]

my rex is having probs with the lower rpms.its like it falls on its face.thought it was the fuel pump but it wasnt.basically it takes forever to get from1000 rpms to 3000.but once it hits 3000 it runs fine.it does it in every gear.and 3rd gear really takes forever.i have a 88 hf and just did a motor swap and put a si engine in it.changed everything but the wiring harnest and fuel injectors.can someone help me?

[crx91]

has it allways been like that after the swap.
could be timing. or your distributer.you could advance the timing by adj the dizzy twards the front .

[88crxsi]

yea its been like that after the swap.but the timing was off 180 degrees and we fixed that.the distributor is brand new.

[honda_luvr_2000]

I bought a dx crx that was running real bad in the low rpms. The guy was selling it cheap for that reason. He had replaced the engine w/ another dx cuz the first one had blown the rings. Well, what I'm getting at, is after looking at it for a while I noticed he had the injector plugs switched around. I switched them back and it ran like a champ. So, you have one of two problems. double check the injector plugs to see if they are switched. however, since u kept the harness and injectors it sounds like that won't be the problem. It really sounds like your timing is advanced a little too much. this would cause the car to hesitate and bog down in the lower rpms, but in higher rpms, the timing actually needs to be advanced and so your engine is actually catching up once it speeds up and it counters the timing. I can explain further the theory for the timing, if you want.

[crx91]

im sure he has them correct.what ecu are u running. and brand new dizzys can go bad. after all they are never new.just remans.i had one go bad not too long ago.but it sounds like retard timing.have u changed ur fuel filter.if ur using ur pm6 ecu off the hf than that could be it. yes tehy use a pm6 dizzy but i think the prog is diff. not sure tho.

[88crxsi]

well we never checked the timing with a gun but it was running really bad and we turned it 180 degrees and it ran a lil bnetter.but thats exactly wat my car is doing is it hesitates and bogs in lower rpms.i put a brand new fuel filter.my hf motor was doing this too but i did the swap cause my hf motor had a bent valve.if u would please explain the timing

[91civicDXdude]

Originally Posted by honda_luvr_2000

I bought a dx crx that was running real bad in the low rpms. The guy was selling it cheap for that reason. He had replaced the engine w/ another dx cuz the first one had blown the rings. Well, what I'm getting at, is after looking at it for a while I noticed he had the injector plugs switched around. I switched them back and it ran like a champ. So, you have one of two problems. double check the injector plugs to see if they are switched. however, since u kept the harness and injectors it sounds like that won't be the problem. It really sounds like your timing is advanced a little too much. this would cause the car to hesitate and bog down in the lower rpms, but in higher rpms, the timing actually needs to be advanced and so your engine is actually catching up once it speeds up and it counters the timing. I can explain further the theory for the timing, if you want.

Base timing (timing at the distributor) works as a reference point for the ECU's electronically controlled timing. If the timing is too advanced (at the distributor) at idle, it will be too advanced at higher rpm. theres no way the engine can "catch up" to advanced timing as its set in the maps.

d16a6 and d15b6 distributors are internally identical, although the HF has a "TC05" coil and the d16a6 has a "TC07" coil, which is what the b18a1 and other engines use. basically, HF and Si distributors are identical only the HF has a weaker coil. this wouldn't cause the engine to run rough though, as i have personal experience with using HF distributor & coil on a d16z6 and it had no such problems.

CHECK YOUR TIMING WITH A TIMING LIGHT

by guessing you are just avoiding an obvious problem. thats like shooting a hole in your foot, getting dizzy from loss of blood, and then checking to see if you have a cut somewhere and avoiding the fact that you know theres a large bleeding hole in your foot.

[88crxsi]

well i thought the problem was a distributor so i bought a new one to go with the si engine and that didnt fix it.if the timing was done with a gun what else could it be?is there anything else that could make it hesitate and bog in lower rpms?not to mention my si motor is sopposed to be running 40-45 psi of fuel and its only running 32.the only thing we havent changed are the fuel injectors.im using a ecu from a 90 integra ls.

[crx91]

that shit will make ur car run too rich.my friends si would shutt off at times.try and find the right ecu.

[honda_luvr_2000]

Yes I understand that the engine won't "catch up" to the advanced timing at the dizzy, because the ECU advances due to the programmed curves, but it wouldn't be as much of a problem in higher RPMs because the engine is spinning faster and is able to over come the advanced timing. Basicly, if this is the problem, that you're too far advanced, then eventually you're going to blow it up. u need to check it w/ a timing light. they r simple to use, but not too cheap to buy, or atleast not that i've seen. take it to a shop and have them check the timing. if they charge you it shouldn't be more than $25. low fuel pressure would have the opposite effect that u have right now, it would be fine in low rpms, and cutting out in higher rpms. so that's not the problem. that ECU would also not be causing your issues, but it will run u rich.

[88crxsi]

ill check the timing and let u know how it went.but if it isnt the timing what else could it be?

[88crxsi]

ok we checked the timing and the timing was fine then we checked the plugs and that was fine too.what else could it be?my ecu is telling me the throttle sensor needs to be checked.could that be the problem?

[honda_luvr_2000]

could possibly be. i'm am pretty much clueless right now. if i think of anything, i'll get back to ya

[88crxsi]

oh ok well im confused too cause i dont know whats causing my car to do this.