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Missing under load, rough idle after repairs.

Joeyrom

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Hi, so I had to replace my intake manifold gasket, recondition the p/s pump, replaced the water pump while I was there and recently had to do the alternatorrregulator. After a few hiccups in that process the car seemed fine until I gave the radiator and engine a flush and change plus a degrease over the engine.

After the degrease and wash down it ran like an absolute dog. Seemed like it was running on 2 or 3 cylinders. Super lumpy and bogged down. I figured water got somewhere it shouldn't have and was done with the thing so left it overnight.

Next morning, it runs fine at idle and revs fine if you smoothly accelerate but if you give it a jab or accelerate too quickly while driving, or while parked, it misses like a bitch. It doesn't matter what temp the car is, hot or cold, only happens when under a full load.

Before I did all the work it had a slightly rough idle but drove just fine. Now I'm not sure what could be causing the issue. Could water still be somewhere it shouldn't and it will get better over time? Could I have instantly rooted a coil? This doesn't make sense to me as it got better after 12 or so hours sitting there.

Reading other threads there seems to be a few things I can check with a multimeter. I already checked the leads and they're fine, but I hadn't touched them. I'll check the coil packs tonight or tomorrow. Anything else to look at before I take it to be diagnosed by a mechanic? A few threads have my exact issue but end and are never resolved.

Cheers.
 

Trevor loves holden.

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Plugs or leads. undo your dfi plug give it a spray with wd40 or similar in the contacts + plug harness and blow it dry. What areas did you wet? if you wet any electrical plugs or sensors do the same as dfi. Water could of got under the coils remove and do as above. Oh contact cleaner be better.
 

Joeyrom

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I am unable to check for codes atm. If it comes to that I'll just get it diagnosed. I'll end up getting one of those plugs in the future.

I sprayed from the manifold down. I tried to keep it away from the coils. Is the dfi plug the bigass plug that goes into the bottom of the coil pack? I'll take the whole thing off and give it a work over while checking resistance.

I'll give the old wd40 a workout tonight. Do I just give it a light coat and plug it back in? No chance of messing things up if theres a bit floating around?

I'll also be waiting til dark to see if there's any sparks arcing where they shouldn't to rule that out.
 

Joeyrom

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There's a line going from the corner on the left towards the purple stamp. I forgot to bloody do the multimeter test before bloating it back together!
 

Trevor loves holden.

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Since you replaced the intake and took the wires off the tps and iac im wondering if its making good contact on the connection, have you cleaned out the Body throttle and iac including the littlie hole in the body throtle, I be cleaning those connections any grime can upset the volts as its very minimal at 5v full throttle, needs to be good clean contact.
 

Trevor loves holden.

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There's a line going from the corner on the left towards the purple stamp. I forgot to bloody do the multimeter test before bloating it back together!
On the picture its bottom left, don't think that's going to cause a problem that's cracked due to bolting down.
 
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