Re: Mahindra Scorpio : Starting trouble Here is another problem which got solved today – that of starting trouble – which is because of air leak in the fuel intake system. I had to prime the filter every time I have to start since there is a massive air lock in either the fuel filter body or the feed pipes leading to the fuel pump (this applies only to the old engines, not the crde, which have a different configuration altogether). You unscrew the feed pipe screw and you can see air bubbles aplenty. I changed the copper washers for the feed pipes but that did not improve the situation. Next suspect is either the feed pipe itself (which was changed recently, may have a leak in it) or the filter body itself. Needless to say, the ASC guys throw all sorts of weird theories – “your fuel pump is defective”, etc.
Over a period of 10 days, the problem worsened and 2 days ago, when the fuel was in the reserve, the engine started spluttering and finally stalled in mid-traffic. Although there was fuel in the tank (as was evident when I unscrewed and primed the air screw in the fuel filter body), either flow pressure was inadequate or there was some vacuum build-up which meant I was not able to get enough fuel to the engine. After refilling some fuel, I managed to start the car with quite some difficulty - with priming for over 10 minutes - since it was obvious that the entire fuel lines were air-blocked.
The intriguing thing is when I did a free roll of the car (pushing, I mean), I started hearing a "khatak-khatak" sound which sounded ominously like the starter ring. I had replaced my starter ring along with the clutch plate in July before the Ladakh trip (the starter ring had chipped off in 2 places).
After consulting m.khanna and spike arrestor and several others, I decided that the fuel system needs to be flushed and bled. One theory was that since there is a small dent in my fuel tank (undoubtedly caused by hitting stones, underbody hits, etc during my recent Ladakh trip) may be causing either muck to collect or vacuum to build up restraining free fuel flow from tank itself to the fuel pump in the front.
What was done at the ASC today to solve the fuel supply problem?
Phase 1
1. Changed the fuel filter – it was in a bad shape after the Ladakh trip
2. Changed all the copper washers in the fuel filter body and the fuel connections
3. Removed the feed pipe from the filter to the fuel pump, found it had a iron washer, changed it to a copper washer (how did the iron washer get there? I had replaced this pipe sometime back.
4. Cleaned the aforesaid feed pipe with compressed air
Started the car, it started immediately. Restarted, no problems.
Phase 2
1. Diesel leak seen, ASC started blaming the fuel injection pump (FIP) – but that was not the reason
2. Close examination revealed that the leak was coming from the main feed pipe from the tank to the filter
3. The main fuel pipe was found to have brushed against another wire/ pipe and there was a worn our portion with a small hole
4. The main feed pipe was replaced. I had replaced this pipe sometime back at TVS, Trivandrum (Apr 2011) - it was obvious that they had fitted the pipe without bothering about routing it properly (do they know there are things like tie wires?)
5. Closer examination revealed that the fuel return pipe from the FIP to the tank also suffered from a similar abrasion – maybe the main and the return fuel pipes were rubbing each other – and that was also discarded and replaced. This is the first time I am changing this one.
6. After all this was done, fuel flow was immediate and engine fired up immediately
The FIP leak happens only when it overflows or is under pressure because of clogged injectors or some such thing. It leaked today too when priming was done. Once the pressure eased off, the leakage stopped immediately.
The problem looks like it is solved, but is still under watch. I have not touched either the fuel tank (which undoubtedly must be filled with muck of the last 6.5 years) or the FIP (which MICO BOSCH guys don’t recommend servicing unless the problem intensifies, and the problem of the leaking O Ring has been stable for the last 2.5 years now). |