[Palumbo_Racing]

This may be a stupid question but I'm going to ask it anyways. I bought my first 1991 Honda CRX HR car today. It's my first 4 cylinder engine. I've always been a V8 person chevy muscle so I don't know a lot about these cars although I have researched and researched them as much as I could.

Since I got this car it has been having stalling issues at 4500 rpms if I push the throttle to the floor when it hits 4500 rpms it just bogs out bad like the rev limiter is stopping it or something. It's been kicking my ass not being able to really get on the car hard before shifting. I know that is not normal 4500 rpm's for a 4 cylinder is just getting started. So I started checking things well I ran the model number of the ecu in the car and it's...

37820 PM6 L09
1.6L Civic Si

Which obviously is not the correct ECU for this car. From what I have seen and read on the net and ebay the correct ECU for this car is...

37820-PM8-A02
88-91 1.5L CRX HF

Would this be the reason why my engine is not performing like it suppose to be performing? The engine has a cold air intake and headers. Other then that I have not seen any other modifications although injectors and other things are possible. I really do not know for sure. All I know is 4500 rpm and it stops performing altogether. Just bogs out and if I keep the throttle down it tries to bog out till I dies. I would imagine that ECU could be the issue but then again swapping ECU's may be something you can do with Honda. I want some insight on this from anyone willing to help out. I appreciate you reading this and any info is greatly appreciated. I have already found the right ECU on ebay for $50 I just don't want to go purchasing an ECU if that is not the exact problem here. $50 is a lot of money for me right now but I need my car performing like it was meant to perform. This bogging out is driving me stupid. Thanks for your time.

 

[EnJoiThaRex]

Switching the ECU isn't necessarily a big deal, but just make sure the sensors that need to be connected, are connected.

 

[RedWabbit]

it would really depend on what engine is in the car if it was swapped out to the engine that matches the ecu then its something else if its the stock engine then yes that might not be the right ecu and its dumping way to much fuel into the cylinders

Switching the ECU isn't necessarily a big deal, but just make sure the sensors that need to be connected, are connected.

ecu makes a big difference. before the civic got taken I swapped the ecu back to the old stock one which is non vtec y7 ecu it would not run the z6 properly at all. it would not idle and had barely dorve

 

[EnJoiThaRex]

it would really depend on what engine is in the car if it was swapped out to the engine that matches the ecu then its something else if its the stock engine then yes that might not be the right ecu and its dumping way to much fuel into the cylinders

Yeah, maybe but i mean i had a Pm6 on a 1.5. It just had the MPFI swap done to it.

OP. What does your intake manifold look like?

 

[Palumbo_Racing]

I would imagine it's the original engine. The block has D15B0 on it but I am not 100% sure which block was original in this car. I haven't really done enough research on that to know for sure but a 1.6L ECU on a 1.5L engine sounds to me like the issue but like I said I dunno. I an not an expert with this stuff. I'm learning as I go.

 

[EnJoiThaRex]

ecu makes a big difference. before the civic got taken I swapped the ecu back to the old stock one which is non vtec y7 ecu it would not run the z6 properly at all. it would not idle and had barely dorve

Ones setup for Vtec ones not. My setup drove though, thats what im saying. Sometimes its a HUGE deal and other times its not as important. It depends what ecu he switched, like an Pm6 or pm7 <--just about the same.

I would imagine it's the original engine. The block has D15B0 on it but I am not 100% sure which block was original in this car. I haven't really done enough research on that to know for sure but a 1.6L ECU on a 1.5L engine sounds to me like the issue but like I said I dunno. I an not an expert with this stuff. I'm learning as I go.

But your intake manifold, does it look like it has 4 inj?

 

[Palumbo_Racing]

Ones setup for Vtec ones not. My setup drove though, thats what im saying. Sometimes its a HUGE deal and other times its not as important. It depends what ecu he switched, like an Pm6 or pm7 <--just about the same.



But your intake manifold, does it look like it has 4 inj?

Yeah it's programmed fuel injection not the TBI injection like the DX's have. It's the same injection the si has from what I have seen. It also looks a lot like the injection on a 91 Integra GS.

If you don't think my problem is the ECU what else could be causing my engine to stall out bad at 4500 rpms? It won't push anything over that when it hits 4500 it's bogging bad.

 

[EnJoiThaRex]

Well you swap ecus but im not saying its a guaranteed fix. Map/maf sensor can cause these problems, moreso maf. Mayb a bad TPS too

 

[Palumbo_Racing]

Well you swap ecus but im not saying its a guaranteed fix. Map/maf sensor can cause these problems, moreso maf. Mayb a bad TPS too

Well I figured out the problem. I noticed the timing belt had been pretty lose and I tried to tighten it and it was already tightened all the way. It had apparently gotten so lose it jumped a tooth on the cam gear or something. I got it timed right now and put a new belt and it's running like it's suppose to run now so I appreciate all the help from you guys. It definitely wasn't the ecu.