Sluggish Mi16

[24seven 104]

I'm rooting for a poor spark/earth somewhere. My previous engine loom (2row) caused all sorts of troubles, not least of which was poor earthing. I temporarily put an earth strap from the head straight to the battery and immediately noticed an improvement in performance at low RPM, just because it's sparking doesn't mean it's sparking well, a strong spark will make a difference.

 

The speeds in gear you mentioned seem to correspond better with a 1.6 box according to a gear ratio spreadsheet I found on this site some time ago (I'll see if I can get you the link).

 

MPH on a 1.6 box at redline (7200rpm):

1st 2nd 3rd 4th 5th

36 64 88 112 138

 

On the 19 box:

1st 2nd 3rd 4th 5th

45 71 97 123 151

 

 

If it is on a 1.6 box, a standard Mi when working properly will hit the limiter in 5th easily.

[Guest BigErn]

Thanks chaps. Is it possible to ID the box thats in mine? Are there numbers stamped or a tag anywhere?

 

I havent had a chance to look at it the past few days, Im trying to source a n/s rear quarter glass for it seein as mine is no longer there

 

And WP, I THINK its about 4k rpm at 80mph but Im probably wrong. Ill check next time I use it.

I just think my 205 is a bit long legged in the first 3 gears. My old Cavalier and Astra XE both had various boxes in and all were pretty similar wether they were F16cr, F16, F18 or F20.

1st (35-40mph) - 2nd (55-60mph) - 3rd (82-90mph) - 4th (107-115mph) - 5th (127-145). Obviously all depending on far out the speedo was though

Edited March 2, 2010 by BigErn

[paul205mi16 4]

My alloy block Mi16 on a 1.9 Gti box does allmost dead on 80MPH at 4000RPM in 5th gear, I'd say that is what you have too.

Edited March 2, 2010 by paul205mi16

[kyepan 291]

i'd still vote for rubbish earths :

[Guest BigErn]

I MUST get round to checking out the earths too, Im just getting lazy

 

On the plus side I got a glass for it so my enthusiasm has regained a bit. Gonna give it a clean up inside tomorrow cos its still full of glass and junk, then maybe get a look at the earths.

[kyepan 291]

mine has got s*it earths at the moment, evidence of this..

 

when i rev the engine the interior heater fan changes speed, as the alternator ups the voltage.

 

when i use the indicators, the interior heater fan changes speed in time with the flashes...

 

 

must sort earths.

 

 

Also i think it may be due to fuel pump wiring, because on the cold start cycle it's got bags of go, but when it leans out for normal running when warm... gutless as a french man on the battlefield.

 

i surmise earthing is the cause of my woes.

 

Richard (drsarty) gave a good tip, run the car then use a volt meter from various bits of the engine or electrical components to earths (bits of the body) if voltage shows up... then that bit needs better earthing, he cured funny running on his zx by figuring out that the ecu was poorly earthed, and the afm was poorly earthed...

 

fixed pretty simply.

 

cheers

 

J

[welshpug 1,626]

are you sure that's not just a dead alternator Kyepan?

[DrSarty 90 1 Cars]

Richard (drsarty) gave a good tip, run the car then use a volt meter from various bits of the engine or electrical components to earths (bits of the body) if voltage shows up... then that bit needs better earthing, he cured funny running on his zx by figuring out that the ecu was poorly earthed, and the afm was poorly earthed...

 

fixed pretty simply.

 

This is true, except for the AFM bit as it doesn't have one. He means the throttle body.

 

Simply place your multimeter (set on 20v DC) across the negative batt terminal to various bits on the engine. The reading should be ZERO volts!!!

 

My engine mount and cam cover were showing 1.2v. I added 2 thick earth straps, from the batt neg to a top suspension strut mounting (all cleaned up naturally) and then to a nice bolt on the engine, in contact with both the head and the block. The multimeter then read 0v as it should.

 

When I checked the throttle body - even after the above - it was still showing just under a volt. A quick linking earth strap to a screw on the TB and it was zero.

 

Since then the engine has run much, much better. This was on top of a previous owner obviously wiring in a fuel pump immobilisor switch, which they then removed and only twisted the wires together.

 

This, when the lambda was plugged in, all resulted in a voltage drop across the ECU and fuel pump, and the car lacked guts. It struggled up hills and hesitated. In fact it hesitated so much once I booted it in anger, and the excess fuel backfired and blew the backbox to pieces.

 

So: this IS on topic and there is a lesson here. You DO NOT need fancy eGay earthing kits with gold connectors and colourfl wires. But a few simple tests and adding a few wires to cleaned up earths on the engine, gearbox or chassis, could save you wasting money on double relays (£40), new O2 probes (£80) and diagnostic tests (totalling another £80), AND get you your performance back again.

 

Trust me. Been there, blown up the backbox to prove it.

[welshpug 1,626]

Hey Rich, did you ever get it sorted or was it an expensive Taxi for the Flight?

[DrSarty 90 1 Cars]

Hey Rich, did you ever get it sorted or was it an expensive Taxi for the Flight?

 

Yep all sorted; and it flies like the wind again.

 

All the faffing about lambda, TPS, IAT and double relays utterly pointless.

 

Sort your grounds out. It really is a must.

[C_W 3 1 Cars]

I don't think it will be the gearbox IMO. With either a 1.6 or 1.9 gearbox it's still a 160bhp/910kg car and would be quicker than a MK3 Astra GSi. Mine was fast with a 1.9 gearbox, it just got much better (more flexible) with the 1.6 final drive.

 

Flat out through the gears the 1.9 gearbox has same close ratios so never drops off the boil, it's just they're a bit longer.

[Guest BigErn]

Right I got 10 minutes to look at it earlier....

 

I decided to change the Coolant Temp Sensor cos it looked as old as the engine and it was for peace of mind for the sake of a few quid. It has made some differnce to the car, it idles nicer, seems more responsive on light throttle and pulls a bit stronger up the revs. So that was £13 worth spending.

 

Secondly I thought I d have a quick look with the multi-meter....... my top engine mount has 1.3v running through it and the cam cover 0.7v. Earthing is definately the next priority job and we will see how it goes from then on.

 

Thanks for all your help so far folks, it has been much appreciated.

[Guest BigErn]

Right its been a few weeks since I last posted.

 

Still disheartened with the car

 

After cleaning all earths and adding a couple of new ones, to be sure, it seemed a bit better again. I then checked all sensors to the readings on Autodata and everything was spot on. Fuel pressure is a fanny hair over 3 bar at full throttle. I even took it to a local tuner who is/was well known for being a wizard with the older engined stuff. It came back from him with a total clean bill of health, he checked all sensors again to be sure, checked compression (180 on the dot across all 4) and a few other bits and bobs. The only thing he adjusted was the CO and told me it was a real healthy engine.

 

The car really still lacks any pull. Its getting to the point now where Im considering selling the car and going back to the Vauxhall C20XE motor. Im disappointed after hearing people rant on about them for so many years.

 

Any further help or suggestions would be appreciated fellas.

[DrSarty 90 1 Cars]

Have you been in someone else's similar spec'd car yet?

 

If that feels the same, then I would say perhaps your expectations are a tad too high.

 

I can't under any circumstances say an Mi16'd 205 would feel slow (sluggish maybe if unhealthy - but never slow), and likewise there's no reason on earth a similar 1.9 or 2.0L 16v from another manufacturer would feel significantly faster IMO.

 

So in short, either something's still up mechanically, or your impression of the speed or delivery of power is a little wide of the mark of what it should be.

 

A 205 Mi16 is a rapid piece of kit, but because it's an overall package, not because it's the world's quickest sprinter.

 

It would really be a shame if this remains your impression of the one chassis and engine combination that has given me more motoring pleasure than any other.

[JRL 14 1 Cars]

so its a healthy engine confirmed, compression tested, all the earths have been done, emissions tested. Remember me saying about the mi16 doesnt like gear boxes without the 4.4 cwp? with the gearbox i had on it it would rev well had good compression but it did not shift well. All my mechanics, friends and enthusiast were scrtaching their heads i then swapped the box for an mi16 and the power and acceleration difference was amazing. if all else fails try it, .

[Guest BigErn]

Sarty, no mate. No one I know has a 205. A mate of mine drove it, who used to drive his mates Mi16 a few years back, and he says mine doesnt pull as hard as this other one. Which was just a standard engine. It has improved from when I first got it by doing all its little jobs. Dont get me wrong, I love the car for the way it drives and handles, Im just getting disheartened with the feeling that its not up to scratch compared to others. I have watched vids on Youtube and all others seem to go pretty good, its just getting on my nerves a bit now. If I knew it was running spot on and was performing as an Mi16 should be then Im planning on getting cams and saving for Jenveys for it, I just want it to be running as it should be before I do anything else to it.

 

Something I need to check is its timing, the fella I got it off says its had a belt on it about 6k ago and he did it himself. Im just wondering if maybe the cam timing is out a tooth or something. It idles lumpy as if it had a set of aftermarket big cams in it too, so it has created the thought the timing may not be bang on. Is it a bugger to get into and check on the 205??

 

What size pins/drill bit/alan keys/bolts do I need to lock the engine up in its "timed" state???

 

JRL, I really dont wanna piss on changing the box mate. Are there any numbers on the box to identify what mine is??

[dcc 855]

it will not be easy to check because of where the cam timing holes sit on the pulleys, right next to the body work! iirc you can un bolt the cam side engine mount and jack the engine up a bit to do it!

 

also, i think mi16 FD in a 1.6 box gives some silly acceleration doesnt it?! get hold of one of them

[JRL 14 1 Cars]

you are right as a last resort do the gearbox, what else can you check? its proven its a good engine and im sure the good tuner guy you took it to would have let you know if the timing was out?? dont get rid of it just yet my mi16 is mental! so glad i didnt get rid of mine i was at the stage of nearly selling it. Its been mentioned before check the throttle is fully opening where I had it rolling roaded the guy adjusted mine and got 5 or 6 bhp out of becuase it wasnt opening enough. im not sure about codes or serial numbers on gearboxes but i put an mi16 be3 box on mine.

[JRL 14 1 Cars]

yeah id love one of those. my mate has a 1.6 be3 on his 1.9 8v and up to 40 or 50 he is ahead then the 16 v start to creep past him. im looking into getting one of these.

 

it will not be easy to check because of where the cam timing holes sit on the pulleys, right next to the body work! iirc you can un bolt the cam side engine mount and jack the engine up a bit to do it!

 

also, i think mi16 FD in a 1.6 box gives some silly acceleration doesnt it?! get hold of one of them