Engine loom problem (Vid Inside)

Looks like an old problem is back with a vengance. I use my car for work (I know can't imagine anything less suitable). I have to travel but it's fairly infrequent so I put up with it.

The problem is that I can be driving along just fine and all of a sudden there is a big loss of power and the engine sounds very lumpy, almost like it's not firing. When this happens I can sort of keep the speed to about 40 till I can pull over.

I had thought this had gone away with replacing the coil packs and sparks etc but it's back. On friday in the snow on the M5/M6 I had to pull over 8 times and it's getting a bit dangerous.

Almost certain it's the engine loom, I had zip tied this off previously to put a bit of tension in the loom and for a while it had been ok. I was hoping it was one of those jobs I could put off to the summer not having a garage or anywhere to really work on the car.

A vid of the problem is below showing normally running and rough...

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From what I can tell it seems to be the right side of the loom, you can see there is a taped off bit in the loom, I had opened that up and checked it over and it looked good to me so I put new tape on and looked elsewhere.

The problem is the loom seems fairly tight where it is and even though I am new to this stuff I don't mind giving it a go. To get to the cable it seems I would have to remove the throttle body stuff to get to it (cant see any plugs) is that a job a newbie could do or should I just take it to a specialist hoping that the price won't be too much as we have narrowed down where it is.

Cheers

Dave

i had exactly the same trouble (even wiggling the loom where you are), turns out the wiring to no1 fuel injector was bad, i changed the plugs and coil clips etc first to no avail. maybe worth giving each injector plug a little wiggle when its running rough to see if it suddenly cures it.

coil pack clips ok?

Yeah I had bought some new coil pack clips before I started doing anything but turns out AFR changed them for the previous owner only around a year ago and they look fine so havent touched them, I have tried holding part of the wire still in one hand and pulling with the other to track it down but its a bit of a rats nest, as far as I can tell the wiress seem ok ultil this dissapear down to the side.

had a very similar fault, it was broken wire strands on my no1 coil pack just before the clip, the insulation on the wire was fine and looked good you can check the resistance of each coilpack wire between the clips and igniter pack plug using a GOOD multimeter. get someone to wiggle the loom as you test each wire.

To test the injector wiring you will have to disconnect the ecu plug and test from plug to injectors. expect a low resistance ie 0.03

The coil pack clips themselves may well be ok, but it's the contacts inside that need fettling too. As soon as you touch the clip it goes rough, so I'd aim there. IanC's walkthrough on here on replacing them shows how to bend the contacts to give a good connection. You need hands like Beadle though to do it with any ease.

Toyota can supply tails with ready crimped connectors for all the connector plugs on the car. That way you renew the contacts and about 6 inches of the wire to the contact, or less if you shorten the tail.

Phew, might finallly have some good news, had this problem since October. I have been out in the snow and ice determined to fix it, with just one of those hanging lights to see anything. As I said above the connectors were changed when I got the car so never thought anything of it but I had each one apart and the small white plastic insert that appears to push the slides onto the pins was damaged on the pack 2nd from the back and on another one so only one bit was getting pushed down. I have bent the pins back into place and will do it properly when I find where I put my replacement connectors but as far as I can tell (really hope its gone now) it seems to be sorted with just a quick blast of WD40.

Just goes to show, doesn't matter how old your connector clips are, knackered is knackered Wish I could have found that out £400 ago

seems to be an ongoing saga matey! i take it the mot was all done, not to expensive??

Heh when I took it through the MOT a second time it had no problems, not even an advisory so all the work paid off...unlike my credit card which is very far from paid off.

lol, & xmas too.

Ok same area but different cause it seems! I replaced 3 of the white plastic inserts on the other pack connectors and all seemed well.

I got to the one I identified as the troublesome one and checked the wires over and...

A connector pin clean in half! it's going to be tricky to get these over christmas and new years so I have done a quick bodge for now by plugging wire into the plug to make up the space and tying the wire in there.

Does anyone have any spare or can someone please put up the part number and I will get myself some, Chris is this is something you carry please let me know.

So there we have it, over £400 for something that could have been fixed for about 20p!

The wire terminal repair section part numbers are 82998-12440 for a 160 mm long tail and 82998-12590 for a 500 mm long tail. I have run out but will be re ordering in the New Year If you need them quickly you should be able to VOR them from any Toyota dealer. The tails are more like £3.50 quid each, not 20 pence But I take your point. I'd replace them all.

Cheers Chris thats most helpful! I have to pickup 2 new bonnet seals and and a brake kit tomorrow anyway off them (hope parts dept is open), I will see what they say or be in touch. Top stuff!