Gtx kjet wont rev and lumpy idle on cold start

BlackGTX · Post by **BlackGTX** » Fri Mar 18, 2016 5:29 pm

Hello,

Have bought an 87 gtx 8v kjet but it has a rough start problem, sound like its only firing on 3 cylinders

It wont rev freely till warm, the volt meter moves up and down with the lumpy idle

Its had a new dizzy cap and leads by the last owner but the leads may still be part of the problem

scrappy1382 · Post by **scrappy1382** » Sat Mar 19, 2016 2:45 pm

try the wur ( warm up regulator )

BlackGTX · Post by **BlackGTX** » Sat Mar 19, 2016 4:52 pm

Ok thanks, my experience for the last 8 years has been with mk2f polo gt's and digifant fuel injection

Taking a while to come to terms with the 80s

mark1gls · Post by **mark1gls** » Sat Mar 19, 2016 9:08 pm

How old is the rotor arm and spark plugs and have you checked what colour the plugs are?

Try unpluging the 5th injector electrical connector (blue plug) as you may have leaking injectors which drip fuel into the cylinders overnight and when you start the car from cold the 5th injector sprays even more fuel in and the engine is flooded when started and runs lumpy till the fuel is burnt off the spark plugs.
I had this problem and ran with out the 5th injector for 12 months till I fitted new injector.

Also check the fuel filler neck for rusty holes by shining a torch down the filler neck.

BlackGTX · Post by **BlackGTX** » Sun Mar 20, 2016 7:30 am

Rotor arm and dizzy cap are new, by the last owner hunting the problem down, was on here.

Will check those out, thanks. What i did do yesterday was new spark plugs incase the porcelin and cracked and was arching to the head

Took it for its first run, it gets the love from other drivers

mark1gls · Post by **mark1gls** » Sun Mar 20, 2016 8:20 am

Did the last owner post up the problems on here?
It may save alot of typing if we know what has already been done/tried.
Copy and paste the link?

Just had a look around and did you buy the car from Mattrocco?
Try the 5th injector again for a couple of days and clean out the AAV...
viewtopic.php?f=12&t=19569&p=136423#p136423

BlackGTX · Post by **BlackGTX** » Sun Mar 20, 2016 2:57 pm

Yeah thats the one, my gt has a similar valve on the inlet isv in that case

Post by **GT Matt** » Fri Mar 25, 2016 2:13 pm

As above, try Warm Up Reg on front of block. ALL the fuel passes through that before it enters the metering head and it can block (small gauze in inlet port). I had very similar problem from cold and replacement transformed mine.

Where in UK are you based?

BlackGTX · Post by **BlackGTX** » Fri Mar 25, 2016 7:29 pm

Im in the south, west susex

Post by **GT Matt** » Sat Mar 26, 2016 7:07 am

Shame, I'm bang in the middle near Derby. Would have had a look at it for you.

BlackGTX · Post by **BlackGTX** » Sat Mar 26, 2016 9:48 am

Im use to it, same on the polo forum, everyone is in the mids

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Gtx kjet wont rev and lumpy idle on cold start

Gtx kjet wont rev and lumpy idle on cold start

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Re: Gtx kjet wont rev and lumpy idle on cold start

Re: Gtx kjet wont rev and lumpy idle on cold start

Re: Gtx kjet wont rev and lumpy idle on cold start

Re: Gtx kjet wont rev and lumpy idle on cold start

Re: Gtx kjet wont rev and lumpy idle on cold start

Re: Gtx kjet wont rev and lumpy idle on cold start

Re: Gtx kjet wont rev and lumpy idle on cold start

Re: Gtx kjet wont rev and lumpy idle on cold start