4x4 running problems

[4x4kiwi]

Greetings from down under New Zealand. The car is a 1990 red top 4x4. I have just read the post from capt cotswold but I believe my problem may be more electrical in nature (almost like timing out) so have started a new post. The symptoms started as just an occasional miss when under load going up a hill almost like running out of petrol so I guess the fuel pump wiring mod mentioned would be a good start. Then it progressed to when you started the car from cold it would hardly run hunting and missing, dropping right down as if about to stall then it would sort of knock then pick up again sometimes backfiring. (never actually stalled but it sure seemed like it was going to) Usually it would come right when warmed up a bit. Now as you drive along the car feels like it dies tacho drops to zero then it restarts usually with a large backfire and plenty of smoke out the back. (this may just be that fuel is still going in but not being ignited until the car fires up again.) All I have tried today was to reseat most of the sensor plugs including ECU and did as many static resistance readings of sensors from ECU plug as I could - all seemed within spec. Do I read that the 3 big engine loom plugs at firewall have been known to cause problems. This problem is very intermittant although obviously getting worse but when not happening car seems to run fine seeming to eliminate any hard failed sensors. Any help would be greatly appreciated. Thanks David

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[oldford]

Tacho drops to zero because the ecu stops igniting. That could be a problem with the crankshaft sensor (or it's wiring) or the dizzy. Do you have the possibility to read fault codes?

[1cosworth]

hi m8 , as above check the dizzy the cap change the engine sensors so you can have a clean start if the problem continues, fuel pump wiring is vital make sure you check it or better replace it the wir. diagram floats somewhere in the forum (sorry i dont have it)heat shield in front of the turbo is very important in my opinion make sure the cossie you have has one. if not the loom on the wall needs a good checking.

[tabetha]

I would also look to the CPS, the bit that gives problems isn't the sensor itself but the connector, specifically the loom side of it, over the years the prongs lose thier grip on the male pins, try the wiggle test when hot and idling.
tabetha

[4x4kiwi]

Thanks to you all for your suggestions. I do have the information for reading the fault code but haven't actually made up the circuit as yet. Does the ECU log the fault if it is intermittant or only if a sensor is faulty at the time you are checking the codes. I think the CPS does sound like a good candidate as the symptoms when idling are as if it doesn't know where in the cycle it is which is why I mentioned the timing. I also suspected crossfiring. I will get out and try your suggestions and let you know how I get on. Thanks again

[oldford]

Symptoms will be the same for both the crankshaft sensor and the dizzy. Doesn't matter which one is faulty. In both cases the ecu will loose sync.

[martysmartie]

ECU will log a fault if sensors go above or below a predetermined threshold if just loose connection may not log nothing, as said check the CPS connector as the pins are vulnerable on these.

Martin

[tabetha]

Symtoms will NOT be the same for phase sensor and cps, once running the position read by the phase is locked, it will not be looked for again until after switch off, you can start the car and disconenct the phase sensor and it will make no difference.
If it doesn't find it to start with it will normally go into seriously stupid rich, and would be basically undriveable, suspect it would batch fire with no initial phase sensor.
tabetha

[4x4kiwi]

Finally found time to work on the problem. Connections on loom end of Crankshaft posn sensor plug did look to be opened up a bit so inserted small screwdiver and bent them back together. Is it possible to extract these pins to retension them properly. Other than that sprayed this and other connectors including three large firewall plugs with contact cleaner. Have had no re-occurance of fault for two days now so fingers crossed it was that plug but is was fairly intermittant before. Thanks again to you all for your help. David

[tabetha]

Yes it is possible and easy to extract the terminals, pm me your addy and I'll pop some new terminals in the post for you FOC, CRIMP them on do not under any circumstances solder then new ones on.
tabetha

[4x4kiwi]

Thanks for that Tabetha. I think I have sent you a PM. Haven't done it before so not 100% sure if it went or stored somewhere on mine. Hope you remembered I was from downunder when you made the offer. Let me know if it costs too much and I will refund you somehow. Thanks again. David

[tabetha]

Hi,
I got your pm no problem, and replied, I will get these away this week for you, I might as well include new male female connector housings if you want, say £4 posted is that ok ?
I'm still happy to send some terminals FOC if you just want these.
tabetha

[4x4kiwi]

Tabetha, The 4 pounds (we don't have the symbol on our keyboard only the $) is fine but do you know the best way to get that to you. I am not sure if I can transfer straight into an overseas bank account with internet banking. I will enquire with my bank and let you know. David

[tabetha]

Hi David,
The easiest way really is paypal, if not I'll give you a NZ account to put it in no problem(don't ask!!).
tabetha

[4x4kiwi]

Either option is fine with me. You will have to let me know either the NZ bank account number or some information on how to do the paypal thing. I think I have paid for something by paypal before but it was by clicking on a link in something like Trademe( A NZ auction site like Ebay) David

[tabetha]

You should sign up to paypal it's just so convenient for paying and being paid.
tabetha

[4x4kiwi]

Hi Tabetha. I have managed to sign in to my old paypal account that I set up some time back. If I read it correctly it appears I now only need the email address that your paypal account is linked to to send you the money. I don't know if you want to put it up here or send me a PM. If this is not correct let me know how to proceed from here. CheeRS David