Low on Power (obd1 m52)

[shootnjunky]

"Also, at times, just as I put the clutch in to go to neutral, it will die"

^this

[TeXJ]

I had the clutch die thing happen and then I replaced the pcv and it’s been fine

clutch die thing?

[shootnjunky]

I had the clutch die thing happen and then I replaced the pcv and it’s been fine

[TeXJ]

I've thought about going from obd1 to obd2, was told that that would be a big process to complete.

[2mAn]

Low on Power (obd1 m52)

Well, you’re getting there. I’d start with a new o2 just as a precautionary and maintenance item and work from there. Chip should be easy to swap if you know someone who also has a similar setup.... hopefully it’s not the Harness. Is it fully modified or do you have an adapter...

I just had a random idea. Since you’re in MN, if the o2 doesn’t do anything and it appears to be electrical have you considered upgrading to a OBD2 setup with all the BS deleted from it? Better diagnostics should another issue arise

[jhaurimn]

smoked tested car, no leaks. pretty much have my issues down to the possibility of:

-vanos seals (although this should cause idle issues which i am experiencing)
-bad o2 (o2 is less than 2 years old)
-bad chip (trm)
-bad harness

[robby41]

i am having a similar issue with my 325e. it will fall off its face and would buck down at 70-75 or around 35 mph. cleaned icv multiple times and that fixed it for a short time but the problem always came back. changed spark plugs and ordered a coil and fuel filter.

[jhaurimn]

Will do, and if you happen to find a solution let me know as well. More than likely gonna let a mechanic look at mine.

Sounds good. I will definitely keep updating this thread as i attempt to fix the problem, cant wait for the update that I do finally fix the issue. Ive been at it for 3 months now. :/

Going to try a "cigar" smoke test tomorrow to see if i can spot any vacuum leaks, and check the exhaust back pressure just to rule it out. My car seemed to produce a suction noise on cold starts that seems to get louder, so I am going to inspect tomorrow morning. I can see a steady stream of smoke out of the exhaust so I don't think that's the issue, but i want to rule everything out at this point that I can.

[TeXJ]

sounds exactly like my issue, just that its all at a bit higher rpms on my end.

if you find a solution for that, please post back on this thread :)

Will do, and if you happen to find a solution let me know as well. More than likely gonna let a mechanic look at mine.

[jhaurimn]

Seems I have about the same issue as you. obd1 swapped m52b28, stock everything running a red label 413.

When coming to a stop, car in neutral, foot depressing brake, the revs go from about 700 then to 1k rpms...till I'm stopped, then it levels out. Also, at times, just as I put the clutch in to go to neutral, it will die. Doesn't happen often but it does that as well. This is with or without the AC on. IAC is good.

sounds exactly like my issue, just that its all at a bit higher rpms on my end.

if you find a solution for that, please post back on this thread :)

[TeXJ]

Seems I have about the same issue as you. obd1 swapped m52b28, stock everything running a red label 413.

When coming to a stop, car in neutral, foot depressing brake, the revs go from about 700 then to 1k rpms...till I'm stopped, then it levels out. Also, at times, just as I put the clutch in to go to neutral, it will die. Doesn't happen often but it does that as well. This is with or without the AC on. IAC is good.

[jhaurimn]

New coils did not change a thing.

Would crank position sensor, o2 sensor, or vanos seals effect the idle?

I still have an idle issue where it goes up to 1.2k when warm (idles around 850 when i start it cold) and the rpm hunts when i come to a stop in neutral. I think this idle issue is related to my power issue.

[jhaurimn]

thought i had fuel issues completely ruled out.

measured fuel pressure during a 15 minute drive yesterday, idled at 40 and went up to 50 at full throttle. Everything seemed normal. still was getting power issues/hiccups while fuel pressure read perfectly.

drove today with pressure gauge still installed and now its reading at 30-38, and does not budge under throttle/load.

now i dont know if it is indeed a fuel pressure issue, or my $70 fuel pressure kit i bought just for this issue failed after one single use.

[2mAn]

Yea doesnt hurt to have spares. I basically mixed and matched the best boots and coils because I wasnt quite ready to spend the $300. It worked for me

[jhaurimn]

I think its the coils. They simply have a shelf life and most swaps are on the original 20-25 year old coils. OBD1 should have 2 grounds in the middle of all the coils too grounded to the valve cover. The coils are usually date stamped. Its not cheap, but that was the only thing that gave me a problem with the OBD1 M52 motor

Found a cheap set of used ones on ebay that look nicer than the ones I currently have. Going to swap them out to see if there is any difference before I drop much more money on a new set. ($30 vs $300)