Ghibli Progress

Messages
52
#1
I've owned my Ghibli for many years. I bought it as an insurance write-off with accident damage to the lh rear quarter, hub and suspension mountings. This I rectified with bolt-on parts, plus panel repair and a repaint. Then it got pushed to the back of my workshop because the engine wouldn't start.

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When I got round to spending time on it again, I discovered that cause was a melted/siezed fuel pump, which I replaced, and soon she was running again. Months passed - and next time I tried to start her, fuel supply was non existent, an unbelievably, the 2nd pump had melted/siezed. The cause was some sort of additive in the petrol, so I drained and refilled the tank with fresh petrol, replaced the fuel pump again - and she started.

Time passed - and next time I went to start her - no joy. So off she went to the naughty corner.

Two days ago she emerged again, due only to me parting a couple of other cars which resulted in her being pushed into the work area. I was determined to get her running this time.

Surprisingly, the fuel pump was still working - and a good head of fuel at the fuel rail - but she wouldn't start. I tested for a spark - none present. I pulled out my wiring schematic, checked all of the fuses and found 1 to be faulty. Ah ha! I thought - this'll be the culprit. I replaced the fuse and was rewarded with working wipers, but no spark. At least that's one other fault that I won't have to trace...

There was 12v in all the right places - the ECU feed, the electronic ignition modules and the spark coils.. I was beginning to suspect that the ECUs had packed up, so I disconnected one of the fuel injector plugs and plugged in a known good injector. Whilst I was cranking the engine, I held on to the injector and I could feel it pulsing - so at least one ECU was working.

I tested the 4 shaft position sensors - 800 or so ohms when static - rising and falling a bit as the engine was cranking. Everything seemed good, so I checked once more for a spark - YES! there it was - one spark as the engine cranked twice. I put everything back together - but still no joy. So I replaced the spark plugs - still no joy.

Finally, and in desparation (don't try this a home!) I disconnected one of the air input pipes, upturned the leading edge and poured about 25cc of petrol into the orifice. I cranked the engine - and - hey presto - she ran for a few seconds!

I concluded that the fuel injectors must be faulty..

Today I removed the fuel injectors. I set up a test rig - a battery and injector lead, to test for function. I was right - no clicking from the injector as voltage was applied. I suspect that whatever had stuck up the fuel pump had also stuck the pintel in the injector. A judicious tap of the injector against a hard surface had the desired effect. I then flushed the injectors with cellulose thinners by filling them to the brim with and firing the pintel until the injector drained.

I put all the bits back in the right place and voila! She fired up!


More later...
 
Messages
52
#2
..contd

The idle speed was high - too high to even dare to slip her from neutral into drive, so I had to find out why.

I screwed the air bleed screw as low as it would go, but still the idle was an unhealthy 1900 rpm.

I let her idle for a while, to get her warmed up an felt a sigh of relief when I few minutes later, of their own accord - the electric fans kicked in.


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About halfway down the picture there is a crooked hose. If I pinched it, the idle speed dropped. Dismantling it revealed that the pipe joined a 13mm diameter hole to a 13mm diameter hole - allowing that much air into the plenum!

The pipe looks like it has been hand cut - so maybe it shouldn't be like that. Do you know what should be there?

By trial and error, I reduced the orifice down to about 1mm x 6mm, using some 8mm metal pipe inserted into rubber pipe and pinched the end with a pair of pliers.

Now she idles beautifully, the air bleed screw giving effective adjustment.

A good few hours work - but worth it.

More to follow in the next few days...

Duncan
2000 Maserati 3200 GT Automatic
1992 Maserati Ghibli 2800 24v Automatic
1987 Maserati Biturbo Spyder 2.5
 

del mar

Junior Member
Messages
187
#3
Evening,
I have the same pipe on mine, I believe it is supposed to be there.
Underneath it you have the ideal control valve, that might need a clean or replace, it is the same as some 1990’s fords. You also have a little adjustment with the throttle position sensor.
Every now and the. I have idle / stall issues when I come of the throttle.
I found rotating the TPS forward and winding out the air bleed screw stopped it from stalling but would only rev if the throttle was wide open.A little bit of trial and error with both and I can get a better idea and the correct throttle response.
Del
 
Messages
52
#4
Thanks Del,

I've tested the idle control and it opens fully with +12V across it. The bypass hose is just letting too much air in, so the idle speed is way too high. Maybe there's another fault that I need to identify.

Slowly - it's dawning on me. That pipe must be the air feed to the air idle control valve. Maybe there is a problem with my AICV, or the control voltage. I'll take a closer look.

Duncan
 
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Messages
52
#5
.. More progress today...

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I'd booked her in for an MoT test at noon. I just had a few things to check over. The number plate lights were not working. One was broken and the other wasn't getting any electricity through the boot lid contacts. The rear panel contacts were not getting a feed, so I hard wired them from the side lamp. One is now working, sufficient for the MoT. The front side and indicators gave me a bit of trouble and one brake light wasn't connected properly, so all good.

A quick flick of the wipers and washers produced a surprisingly good jet of water and the horn sounded on demand.

There was a small hole in the rear exhaust pipe, which I patched up with the new style epoxy based exhaust repair patch.

The good new is that she passed the MoT. On the way back to my workshop, I took a detour along some country roads. She pulls fine, but is very hesitant at low revs - I guess that's something to do with the air bypass.

I parked her outside my workshop and was treated to a small puddle of coolant on the floor. It looks like the water pump has a slight leak. Oh well - something to do tomorrow, I guess.

I also notice that she is sitting a bit low on the front right corner. I'll look at that when she's on the ramp.

More later
 

ZAM400209

Junior Member
Messages
494
#6
Hey Duncan- that's a peach; well done getting it rolling again; what's the mileage..?

I see you have QP IV wheels and those rubbing strips on the bumpers!

With regard to the OS front suspension height- does your car have the adjustable suspension system..?
 
Messages
52
#7
It's a little more than 51000 miles. It has electronically adjustable suspension - I have no idea whether it works or not - I'm just getting on with the basics whilst I wait for the registration document from DVLA.

Duncan
 
Messages
52
#10
With the old girl now starting on the button, I decided to change the oil and filter. I warmed up the engine and left it to settle for 30 minutes, before draining the oil. What came out wasn't like treacle, but it had been in there for a while. It looked pretty easy to drop the sump, so I did, and discovered that the lower part of the sump was caked in emulsion. I wasn't too surprised to see this, because the engine had been started from cold and not run for long many times over the past years. I cleaned it all off and found nothing beneath it to worry me. Eurospares wanted £39.95 + VAT and delivery for an oil filter, my local motor factor, Jayar Components, wanted £4.66 + VAT, free delivery, so no prizes for guessing which I chose. About 5 1/2 litres of oil was all it needed. When I started the engine, checking for oil pressure and oil leaks, I convinced myself that it was running more smoothly.

I'd like to mention that my local branch of Jayar Components, Aylesbury, have always been very helpful in sourcing parts for old and unusual cars. They often get out the old books, or browse the internet to cross-reference parts to help.

I've just about finished the works on this fine Maserati. The only outstanding issue is to solve the idling problem. I need to tie back various wires and replace trim that I've removed.

I can't drive her properly until DVLA send me a new registration certificate, so that I can get road tax, so I'll be getting on with other projects in the meantime.


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One other thing... Before I start to drive her in earnest, I'll replace the timing belt. Is there an equivalent part, or are we stuck here with Maserati prices?

By the way, I treated the coolant system with BARS LEAKS coolant conditioner and the water pump has stopped leaking - probably just a the seal dried out a bit. I can take a closer look at the water pump when I change the cam belt.

Duncan
 
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Messages
1,254
#11
Great job! Impressed.
I am getting a timing belt just now from David Askew. £25. Didn't check elsewhere to be honest. David is a great guy and happy to give him my business. He has a huge range of other parts you will probably need! Lol
 
Messages
52
#12
Thanks, Needamaser, I'll probably make a list of parts that I need and do business with David.

I found out what was causing the high idle. Having replaced the Air Idle Control Valve, which made no difference, I resorted to the Maserati Fuel Supply manual. It details the goings on and a list of sensory inputs which make a difference to the engine performance. A visual inspection revealed that the coolant temperature sensor plug was damaged and repaired. It sits very close to the throttle/kickdown cable and I think that was the cause of one of the two pins being pulled out of the plug. I replaced the plug (marked with white in the picture and the idle speed returned to normal.

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