Hyundai Santa Fe 2007 Diesel Starting Problem

Nexo

Hi all. Im having a problem starting my 2007 Santa Fe from cold. It starts after a few turns but runs very rough, bellows smoke and then cuts out. It took 15 attempts of this for it to eventually tick over this morning, all be it very rough for the first 2 minutes with little or no throttle response and plumes of smoke. Once warmed up it was fine with no smoke and it restarted without a problem. However I did notice it had a hesitation between 1000-2000 rpm after restarts throughout the day but again this cleared up once it was warm.
I suspect injectors?
Anyone input appreciated?
It has 95k miles on it.

sportchip.ie

look like AGR valve pronlem

glic71rods46t0

I had an almost identical problem with the wife's Hyundai Tuscon 2.0 diesel. If yours is the older model Santa Fe then its the same engine.
Brought it to Hyundai garage at least 5 times. They couldnt identify the problem as nothing showed up in the diagnostic. Initialy suspected injectors then replaced AGR (or EGR?) valve - no change.
It eventually was found to be an engine sensor was at fault (camshaft sensor I think). It didnt light up the engine management light or show on the diagnostic in the garage.
It was a royal pain in the backside as I would bring it in after trying for ages to start it (especially if it was a cold morning) but, by the time I got to the garage the engine was warm and started no problem.
I felt at one stage that the mechanics thought I was making up the fault! I had to wait until it became impossible to start and got it towed to the garage - only then did the garage find out what was wrong with it!:eek:

Nexo

Thanks for the replies lads. My mechanic removed the injectors last night and spotted no. 2 leaking. I'm going to have all 4 checked today at an engineering shop.
I spoke to Hyundai yesterday and their recommendation was to leave it with them overnight so they could replicate the cold start problem in the morning whilst plugged into disgnostics.
Mine is the new model 2.2 diesel.

glic71rods46t0

Nexo wrote: »

Thanks for the replies lads. My mechanic removed the injectors last night and spotted no. 2 leaking. I'm going to have all 4 checked today at an engineering shop.
I spoke to Hyundai yesterday and their recommendation was to leave it with them overnight so they could replicate the cold start problem in the morning whilst plugged into disgnostics.
Mine is the new model 2.2 diesel.

Best of luck with it - I believe that the newer 2.2 engine is a much better engine than the older 2.0 one. But its a bit annoying that Hyundai appear to be unable to diagnose a problem without replicating it - same thing happened to me - I owuld have expected them

Nexo

Engineer got back to me this afternoon saying he couldnt find a fault with any of the injectors. Because they are a new type and apparently very reliable he has not seen any come in with faults to date. To be 100% sure of no faults he wants to check them against a new injector which Im told will be done tomorrow.
Looking like it could be a trip to the main stealer for diagnostics
Fencer was yours very smokey when trying to start?

Nexo

sportchip looks like you could be right. I spoke to another dealer about the problem and they said its likely to be the EGR valve.

glic71rods46t0

Nexo wrote: »

Engineer got back to me this afternoon saying he couldnt find a fault with any of the injectors. Because they are a new type and apparently very reliable he has not seen any come in with faults to date. To be 100% sure of no faults he wants to check them against a new injector which Im told will be done tomorrow.
Looking like it could be a trip to the main stealer for diagnostics
Fencer was yours very smokey when trying to start?

I dont recall it being very smokey to be honest. The EGR valve was replaced on ours as well but didnt make any difference. The scary thing is that nothing showed up on the diagnostics and the Hyundai mechanics didnt seem to know what was causing it. I still wouldnt rule out an engine sensor - but I hope it is an EGR valve as I understand its cheaper to replace than an engine sensor. Best of luck and keep us posted!

Nexo

I will indeed Fencer and thanks for the input. Hopefully Ill have good news soon.

shamwari

I doubt very much if this is an EGR problem as EGR's only affect engine performance when running, and have no influence whatsoever over startup.

The car should be scanned for fault codes first and the live data monitored during cranking. The fuel rail pressure in particular should be checked as if this is too low, then the ECU will not let the engine start. A problem with the fuel filter or air getting into the system on the low pressure side might cause this.

The next check thereafter is an injector leak-off test to establish if there is an issue with leakage in an injector. This is done with the injectors in the car, and involves connecting a small bottle to the leak-off pipe of each injector to see how much it is returning at tick-over. If an injector is leaky, it will return far less into its bottle than its counterparts, and the logic follows that it will be leaking this into the cylinder. I would check the oil level to make sure it isn't climbling as this could indicate diesel getting down the bore and into the sump.

Also if the injectors were removed, they have to go back into the cylinder from where they came as each injector is coded to its respective cylinder.

Nexo

Thanks for the detailed reply Shamwari. Thankfully my mechanic labelled the injectors 1-4. Can the engine remanufacturing shop not determine if they are leaking when they test them? Or is it the case that they have to be in the engine and running?

shamwari

Nexo wrote: »

Thanks for the detailed reply Shamwari. Thankfully my mechanic labelled the injectors 1-4. Can the engine remanufacturing shop not determine if they are leaking when they test them? Or is it the case that they have to be in the engine and running?

It depends on the injector and the rig to which its connected in the workshop. Most of the new injectors are electronically fired so unless the shop has the latest kit then it may not be able to actuate them in a test situation. As the leak-off test can be done in situ, there's no need to remove the injectors physically to do this. I found this linky to a leak test on youtube where flow and spill rates are being measured on a set of injectors. Note the pressure being applied to the injectors is 1350bar. That is serious pressure and underscores why people who don't understand these systems should not mess with them

Nexo

I will have to check with the shop to see if they performed a proper leak test. My mechanic did say when he removed the injectors that there was diesel around injector no. 2. I was surprised when the test engineer called me back today to say they all tested ok and had no leaks!! They are going to test and compare them against a new injector tomorrow to be 100% sure.

Nexo

Turned out to be the egr valve causing the slow starting. The injectors checked out fine. Jeep is still a bit smokey in the mornings when cold starting. Thanks for all the replies folks.