Turns Over But Won't Start

[shatcher80]

I have a 1991 Lexus Ls400 and recently had the fuel pump replaced. Low water temperature light kept coming on for about two weeks, always filled it with water but couldn't find the leak. One day car just runs completely hot so I pull over at a gas station and have it towed to a mechanic shop. He tells me my water pump is gone bad, needs to be replaced and also he would replace the timing belt since that would have to come off as well. This was one week ago and now that the work is finished the car will not start. It turns over but will not fire. The mechanic explains to me that he has done the timing twice and assures me it is correct but the spark plugs aren't getting any fire on both sides. He is puzzled and not sure what the problem can be. Any suggestions?

[curiousB]

Well might want to find a new mechanic. He doesn't seem too dialed in on the root cause.

I don't know what the low water temperature light is. Do you mean the car overheated and was too hot? Also did you add significant amounts of coolant yet don't see any leak or puddle below car? That could be a sign of a blown head gasket where the coolant is leaking into the cylinder and going out the exhaust. That might not be worth fixing on a '91 (repair cost is more than car is worth >$3,500.00). A cylinder compression or leak down test would confirm if this is a problem.

As for the missing spark that seems unrelated but might explain why you can't get it going right now. Any competent mechanic should be able to narrow down why there is no spark. Is it on both distributor banks or just one side? Is crankshaft position sensor ajar causing no spark timing reference to ECU (or drenched in coolant from water pump leak)? Any codes in the ECU log giving some clues to the problem? Can you probe on coil primary to see if it is being pulsed by ECU while cranking? If primary has pulse is there spark on secondary? If spark on secondary what is wrong in distributor causing spark not to get to plugs? Is inside of distributor(s) drenched with coolant as well?....

If the water pump is shot and that is why you are overheating and losing coolant (should be visible as a pink fluid mess around TB covers and below) that is repairable. You should do the timing belt if you do a water pump as the extra parts aren't that expensive and they have to remove TB to get new water pump in anyway. So labor shouldn't be any more. If you change water pump I'd put in new timing belt and new idler pulleys. You can reuse the TB tensioner if the mechanic has a way to compress the old one. If not replace it too.

So I'd focus on the spark to see if you can get it running. Once started you need to know if you have a head gasket or water pump leak for the coolant. If water pump probably worth fixing if you love the car. If head gasket time to call the funeral director and say goodbye to an old friend.

[andyperformance1]

[quote name='shatcher80' timestamp='1284168324' post='41906

I have a 1991 Lexus Ls400 and recently had the fuel pump replaced. Low water temperature light kept coming on for about two weeks, always filled it with water but couldn't find the leak. One day car just runs completely hot so I pull over at a gas station and have it towed to a mechanic shop. He tells me my water pump is gone bad, needs to be replaced and also he would replace the timing belt since that would have to come off as well. This was one week ago and now that the work is finished the car will not start. It turns over but will not fire. The mechanic explains to me that he has done the timing twice and assures me it is correct but the spark plugs aren't getting any fire on both sides. He is puzzled and not sure what the problem can be. Any suggestions?

First check to see if He's an experienced certified tech. If your car was running and after doing the job it doesn't run, The timing gear mark is not properly align. on the ls v 8 there are two sides cam sensors also they are very complecated to to align. its not like your normal timing belt job, i would get another master tech that specialize in lexus get a secound opinion.. i have a diagram and step by step instruction i can e mail if u need.

[curiousB]

Hi AP. Welcome.

Not sure this is much of an issue anymore. OP was September of last year.

[andyperformance1]

Hi AP. Welcome.

Not sure this is much of an issue anymore. OP was September of last year.

sorry didnt see the date but wat end up happenning? What was the cause?

[landar]

sorry didnt see the date but wat end up happenning? What was the cause?

We probably will never know for sure. This is the typical 'dead end' to some threads. Posters come and go. Closure sure would be nice but not much we can do except make sure that our threads show resolution.

[shatcher80]

sorry didnt see the date but wat end up happenning? What was the cause?

We probably will never know for sure. This is the typical 'dead end' to some threads. Posters come and go. Closure sure would be nice but not much we can do except make sure that our threads show resolution.

Hello,

Well I finally got it towed to the dealership and spent over $100 for a diagnostic. After a week the dealership tells me that it was the ECU and quoted $1800 for repairs. Well I got the car towed back home and found a cheaper one on EBay, got my husband to install, and she fired right up. But the timing change was always correct.

[steve2006]

Thank for letting us know,it's good to hear you got it sorted and you are still on the forum