Erratic tickover

Terry Brooks · Post by **Terry Brooks** » Thu Jan 12, 2006 6:08 pm

Hi all ....and Help. ....my '92 TZD 1.7 is playing up ....to begin with it seemed very reluctant to start first thing in the morning [once started it will start every time without problem] ......I added some "Injector Cleaner" fluid earlier this week, I've checked and drained the fuel filter [OK], checked the glow plugs [all OK] and yesterday I took the injectors to my local deisel specialist where he pressure tested them [all OK]
The guy at the specialist suggested I park my car [with a full tank],on a hill, facing downhill ....this he said "would get any air bubbles in the system to return to the tank" ....I parked last night facing downhill and sure enuff,it fired up first time this morning.
I've been a good run in it today [60+miles] and I noticed that the tickover is sometimes [only sometimes !!! ] a lot faster than it should be on pulling up at junctions/in traffic etc..... [ 1500+rpm instead of the usual 950/1000rpm] ......I pulled in and checked if the throttle cable was sticking on several occassions [it was'nt ! ] .....I dont suspect the "injector cleaner fluid" has any connection with the tickover prob because I added it to a 1/4 tankful earlier in the week and filled the tank last night.
I dont suspect any valve/compression/engine probs [cos it felt that it was going like a rocket today ......I gave my buddy a "White Knuckle Ride"

]
Ive parked it on level ground tonight to see what happens re the starting problem tommorrow ....but any suggestions gratefully recieved about the tickover and how/where air may be getting into the system.
Cheers
Terry

mnde · Post by **mnde** » Thu Jan 12, 2006 6:14 pm

An alarm bell has rung...

I remember reading about a BX in the CCC mag, presumably a TD, that developed a tendency to rev at higher speeds at idle, until one day it zoomed up to max revs and stayed there, the owner shoved it into neutral and ran for cover

A little hazy over what was wrong, something about fuel being sucked into the turbo through a split hose, which increased the revs, which increased the suck etc.

Anyone know what I mean??

Mark.

Terry Brooks · Post by **Terry Brooks** » Thu Jan 12, 2006 6:24 pm

Cheers mnde matey .....makes good sense that .....will check the hoses tommorrow [it has been getting worse today]. Will keep ya posted if that is/was the prob.
T.

jeremy · Post by **jeremy** » Thu Jan 12, 2006 6:25 pm

The Roto -Diesel pump uses presurised fuel to communicate with its governor etc (bit like hydraulic suspension I suppose) and is therefore sensitive to air in the fuel and can runaway - which sounds like what is happening to you.

The fact that you have starting problems (albeit cured when the thing slopes forward) suggests that air is getting in somewhere and - it could be in numerous places, even the steel fuel line running from the tank. (Apparently cheap to replace with genuine)

To see if you've got rid of the air leaks you could replace the last feed to the pump with transparent plastic so that you can see any bubbles in the pipe.

The Bosch pump has a mechanical linkage and so shouldn't suffer from this problem. It is however sensitive to air getting in through the leakoff tubes. The Roto-diesel doesn't suffer from this - just leaks and smells.

jeremy