M10 rough running/repair log

[4bangerfury]

I think I'll try bypassing the vacuum valve on the way home from work, see if that puts a stop to the loss of power/bucking issue while driving after warmup.

After reconnecting that wire, the idle is hit and miss. When it's below 60 degrees, she idles like nothing is wrong. Above 60 degrees and the idle fluctuates a lot, like it's trying to control the ICV that isn't there yet.

[4bangerfury]

Bypassing the vacuum valve on the firewall had no effect on the rough running issue, but I may have found the culprit. This is the sound the idle stabilization relay was making when the car was acting up:



That is with the engine off, key in the run position. Once it stopped clicking wildly like that, the car seemed to run normally. It makes sense since the according to the wiring diagrams the injectors are grounded through that relay.

[Acet]

Yep! Same thing here! That middle box in your image, it clicks sporadically everytime the car runs like shit. And youre exactly right, the car can be off and it will still be clicking.

Also, from what I understand here is what bypassing the valve does: the vac advance adjusts timing (advances it or retards it) as it gets vac from that electric aux valve which in turn gets its vac from intake mani. If the valve is disfunctional in any way, that could hinder the vac advance functionality and you would theoretically experience a decrease in performance while in lower gears because the vac advance wouldnt be adjusting the timing to compensate for whatever goes on.

By connecting the vac advance to I take mani directly would ensure that the vac advance is actually performing its function.

What do you think is the way to go about that box?

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[4bangerfury]

I'm trying to find a replacement for that relay. Once I have a working one, I'll think about taking the broken one apart and trying to figure out what went wrong. Would be nice to have a spare/figure out how it works. I see new ones from Germany on Turner for $127.

Now it's kinda funny to drive around. When it starts acting up, i pull over and tap that relay with the handle of a screwdriver until it stops being an artard. Could be placebo effect/good timing when i pull over to tap on that relay, but it seems to work out alright.

[Acet]

Well I jumped on your wtb thread with someone else on here and seems like a few ppl are having similar issue.

I fixed all the vac lines and idle today so that sucker is the only thing I must address before I pull the head.

Other than the intermittent sputter, hows your m10 running overall? Also, have you measured the compression in your m10? What should the good numbers read? 160ish?

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[4bangerfury]

When that relay isn't acting up, and when the car will idle without having an ICV installed, it runs like a champ.

I haven't checked the compression yet. I've never actually done one, I always used a leakdown tester back home, but I don't have access to that tester right now. Someday I'll buy one of my own.

[4bangerfury]

I'm gonna say the rough running issue is fixed. Replaced the change over relay, and it runs like a completely different engine. So much nicer.

Just waiting on the hoses for the ICV to come in and I should have a fully operational m10. Then I can finally focus on fixing the rust on this car.

[gettinscurvy]

change over relay?

[gettinscurvy]

Bypassing the vacuum valve on the firewall had no effect on the rough running issue, but I may have found the culprit. This is the sound the idle stabilization relay was making when the car was acting up:



That is with the engine off, key in the run position. Once it stopped clicking wildly like that, the car seemed to run normally. It makes sense since the according to the wiring diagrams the injectors are grounded through that relay.

OK! So, the fuel pump relay is on the left and the idle stabilization relay is on the right, what is that relay in the center? Also, could you take a picture of the part number for me?

[4bangerfury]

Going from left to right: fuel pump, idle stabilization, vacuum advance.

Part number from realoem for the idle stabilization relay is 13411708511. i'm kinda lazy to run outside and take a picture right now.

[Acet]

so did you find a used one or did you buy one from turner?

[4bangerfury]

Turner. I wasn't getting any responses for used ones until I already purchased the one from Turner. Considering how much better the car drives now, I don't mind spending the extra. If I ever get some free time, I would love to take apart the old one and figure out what went wrong.

[Acet]

Great. Glad to hear youre all operational man! So do you happen to know if the idle control module which you replaced controls the icv or vac advance? Im guessing the icv but not quite sure. The reason why I ask if maybe there is a way to bypass that relay if the icv is gone. Maybe stupid question but just wondering. Thanks

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[4bangerfury]

I don't know exactly what it does, but it has no direct connection to the ICV.

From what I can figure out, it has something to do with going from part throttle to closed throttle. For some reason the ground lead of the fuel injectors goes through the relay and that's what was causing the intermittent cutting out.