ChokolAwt

90 crx dx, stock engine/trans, OBD0.

just recently started happening. car will randomly go into limp mode. either while driving or starting it. i turn the key and i hear the fuel pump prime and the main relay click, but the check engine light stays on and the led on the ecu is solid.

What could cause this? Today, i made it 20 miles to work then right as i got off the interstate it hits limp mode... ran fine on my way home from work.


any ideas? suggestions? things to test first?
Thanks!

83Stang5.0

Hmm, I want to say that if the ECU LED stays solid, thats the ECU going bad. At the same time, I think my 88 Integra had the same issue, but it was chassis wiring deteriorating over time, causing me to scrap the car.

I'll try to check though, I know solid LED is a code.

EDIT: Yeah either bad ground(wiring) or bad ECU from what I found. Havn't messed with obd0 in awhile so I'm a little rusty. I have a PM5 that works for sure you can try, if it works I only want $5 for it.

JDM180SX

totally diff car, but on my nissan 240 my ecu went into limp mode and code came up knock sensor...ended up being the shielded wire. i ran a new wire and she was money again. idk about hondas if you have any sensors that use shielded wire, but they are known for going bad...especially older cars.

my 2 cents

TATTRAT

JDM180SX

throw those into the gas tank lol

ChokolAwt

i have no idea what those are...


well, it's an si engine, so i'd need a pm6 ecu... should have one coming in the mail in a little bit. if an ecu goes bad, wouldn't there be a burn resistor or popped capacitor or something? not just straight FAIL...


the weird part is that sometimes it works, othertimes it doesn't... so the ecu has intermittent failures?

JDM180SX

do you have a way of pulling codes? i mean mine is a 89 with obd1 and i get codes...it might tell you something.

83Stang5.0

It can have intermittent failures, but its more than likely wiring I'd think.

The LED we're talking about is how you check the codes on these obd0 ecu's. The LED flashes a certain number of times to tell you the code when you key the car to run.

JDM180SX

thats how mine is as well it flashes 3 red and 4 green which means code 34...totally diff car, but same concept.

ChokolAwt

how can you check the codes if the led isn't flashing... it's just solid.



i redid my mpfi wiring and made it look cleaner as well as wiring up my lc-1 and i think i fixed it? i test drove it and it worked fine... my only concern is that it was always random when it failed on me, so i guess i'll see...