Help With A V8

[big bad bob]

I have just done a cam belt on a 1992 V8 and now it will not rev It idles ok but will not rev up It just miss fires I have rechecked all I have done and drawn a blank I am thinking air flow meter or fault with the 2 stage fuel pump

Any help would be good

[steveo]

Hi there, cant see it being the fuel pump as the 2nd stage doesnt kick in until its being booted, there is a way to test it tho, if u put a paper clip in 2 of the jumpers in the diagnostic port in the engine, it'll make the pump run in the full mode (altho cant remember which jumpers they are at the mo! will try and find out),

if you've double checked that the belts lined up, im not to sure what else it could be, but then im sure some1 mechanically minded will be along soon :)

[chips229]

Hi,

Did you try what steveo said,could be the timing is out by a tooth on the new belt,could be retarded that might give you the problems you talk...if the engine run fine before the belt change.

Let us know if you find the problem.

Cheers chips..

[big bad bob]

I have checked the cam timming 4 times now I have done a few of these belts over the years and never had a problem is there more than one type of belt for these cars I am using a gen toyota belt

There are two marks on the crank both line up and I paint marked it, on the 2 camshafts I aligned the 2 marks that point at 3 o,clock and paint marked them .

I am at a loss on this one the only other thing that has been doen is a fuel filter and the pipe back to the tank . I dont think this is at fault as it is miss firing .

??????????????????????

[ROYT]

If this ia an Ls 400, check both' dizzy 'caps are fitted correctly.

Are all the plug leads on the right plugs?

[big bad bob]

If this ia an Ls 400, check both' dizzy 'caps are fitted correctly.

Are all the plug leads on the right plugs?

How do you tell if they are on correctly ? I removed the dizzy covers and and tucked them back I did not remove any of the leads .

[soramad]

big bob when you moved the plug leads out of the way is there any chance some of them could have got broken as they can get quite brittle in the atmosphere under the bonnet, i lost my No 5 lead sometime back and this gave poor acceleration and a slight missfire ,i think any more than one broken lead would show up a lack in pick up,also possibly cause the engine to judder as it normally runs without any viabration, where abouts in gloucestershire are you? also i trust none of the pullys got turned when you replaced the belt

[big bad bob]

The car is in Hereford I have not checked all the plug leads so I will give it a try It has done a few miles (266304km) so the leads could not be good I have also been checking the fuel pressure it seams a bit low 90kpa at idle .

Dose anybody know a way to test the pump / two stage system so I can rule this out .

[LennyLexus]

HELLO

Mike & Rob.

BTW Welcome to the club, c u soon.

[Mark H.]

Dose anybody know a way to test the pump / two stage system so I can rule this out .

You can bridge 2 connectors in the diagnostic port to switch the fuel pump to see if the fuel pump ecu is stuffed which can be quite common apparently. I recall reading B and FP (Battery and fuel pump) but i am not certain so please dont try this until you are certain, best to go to www.toyotaimportsforum.co.uk and do a search on there, it should be explained.

There is also a general indepth diagnostics check you can do, this should give you a general idea if anything else it can check needs attention.

[big bad bob]

Thanks for all the help I found that the fuel pump (not the ecu ) Had failed just happend to be when I changed the cam belt Pump was not that dear from toyota !

[Chris Skelton]

Thanks for all the help I found that the fuel pump (not the ecu ) Had failed just happend to be when I changed the cam belt Pump was not that dear from toyota !

WOW! Isn't it nice when it's all fine again after so much mind-numbing anxiety? Time to pop down to that nice Royce Rolls Cafe in Bristol's St Nicholas Market for a coffee and chat with LS400 owner? (Don't speed on the Bristol to Swindon stretch as cameras are watching!)