HJ45 Oil Pressure

Submitted: Friday, Jun 15, 2007 at 12:57

ThreadID: 46694 Views:4200 Replies:6 FollowUps:3

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jonnyNo1

Hi, Can anyone please advise? I have just purchased a 1979 HJ45 Troopy with a H motor. Unfortunately the engine runs for approx 5 seconds and then cuts when started from cold. On second crank it does the same thing but third time lucky. It will start fine and continue running when warmed up. The previous owner mentioned that it was probably the oil pressure switch in the side of the block and that they were set up so that the engine would cut if there was insufficient oil pressure. However, I have changed this switch, but unfortunately no change in the problem. I am running Castrol CSR40 and the oil pressure gauge in the cab reads good.

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Reply By: Member - Toytruck (SA) - Friday, Jun 15, 2007 at 13:43

Friday, Jun 15, 2007 at 13:43

JohnyNo1,
not sure but are you sure its not the EDIC motor shutting off the fuel for some reason??? or there has to be a link from the oil switch to the EDIC motor to enable the engine to be shut down on low oil pressure and there may be a fault in that circuit.

Strange that it dissappears after a couple of times though.

Toytruck

AnswerID: 247041

Reply By: Sweeney - Friday, Jun 15, 2007 at 14:55

Friday, Jun 15, 2007 at 14:55

This is normal behaviour.
HJ47, HJ60 & BJ40's have the same sort of system as a protection against low oil pressure. The main reason why it is shutting off during the first two starts is that the oil pressure has not come to the minimum level. By the third start, the oil pump & galleries would be full of oil and won't take for pressure to come up.
My old man's HJ47 needed a small touch on the accelerator first start in the morning. After that, no drama's.

AnswerID: 247050

Follow Up By: Member - Davoe (Nullagine) - Friday, Jun 15, 2007 at 18:47

Friday, Jun 15, 2007 at 18:47

Yep pretty normal specially inwinter. those shut off solonoids can be pretty touchy.
The 1HZ never had them - bit of trivia can any one explain why the 2h had them and not the 1HZ?

FollowupID: 507918

Follow Up By: Member - Davoe (Nullagine) - Friday, Jun 15, 2007 at 18:48

Friday, Jun 15, 2007 at 18:48

Oh sorry Peters already answered it down below

FollowupID: 507919

Reply By: oldpop - Friday, Jun 15, 2007 at 15:21

Friday, Jun 15, 2007 at 15:21

Hi jonnyNo1
If you change your oil and use 15W40 grade should fix problem
heavy oil takes to long to get the pressure up and there a oil pressure sensitive fuel cut off so engine wont run with out pressure factory inbuilt in case of roll over

regards
old Pop

AnswerID: 247057

Reply By: Exploder - Friday, Jun 15, 2007 at 16:40

Friday, Jun 15, 2007 at 16:40

does the H engine uses a hydro mechanical Governor, I.E if you have no oil pressure the control rack will be moved to cut fuel.

This could be the reason why, as it's taking to long on first start up for oil pressure build up to balance the governor flyweights as she's cutting the fuel.

Just a thought.

AnswerID: 247077

Reply By: Peter 2 - Friday, Jun 15, 2007 at 18:27

Friday, Jun 15, 2007 at 18:27

They are designed to do that if oil pressure is too low, are you using the correct oil? should be 15w40 as has been said.
The reason these motors have the oil pressure cutout is that they will run backwards! I did it once in low range, stalled it going up a hill, it started to slide backwards, I got off the clutch very quickly, it was still in 1st low and brrrmm away it went, black soot pouring out the snorkle till the oil pressure switch cut the fuel off. Was a bugger trying to clean the inside of the aircleaner element!
If it still does it with fresh oil and filter on a hot/warm start it might be time for an overhaul.

AnswerID: 247110

Reply By: Eric Experience - Friday, Jun 15, 2007 at 22:06

Friday, Jun 15, 2007 at 22:06

Jonnyno1
The cause of the problem is the oil pressure relief valve, instead of a ball on a steel seat like most motors the H motor has a steel piston in an aluminum cylinder, the cylinder wears and the piston gets jammed in the position it sits in most of the time.this allows the oil to drain back to the sump. If you want to fix it properly you can ream the cylinder and make an oversize and longer piston. 4 thou is enough most times. Eric.

AnswerID: 247159