end results of lean conditions

[topless82vette]

In a L-98 that had dead multecs my friend took his 90 to a idiot and he installed 19lb per hr ford injectors " the numbers come back as Bosche replacement number for a 302 or 4.6 V-8. Ever since this car has had a cooling issue that originated back when the multecs were dying. Now the car has intermitent hesitation when under a load or when in higher gears and engine is lugging.

what could the ecm potentially do or see in these conditions. If in fact it is lean could this hesitation be the ecm seeing detonation and retarding timing and if it was continuosly doing this could this explain the high coolant temps?

Can the ecm correct fuel issues to make up for the 19lb injectors and or is 19lb injectors to far out of range for the ecm to make corrections and it is unable to deliver enough fuel?

What do aluminum heads and 10.25:1 compression suffer from lean conditions?

aside from this car having a very minor coolant leak and it doesnt leak all the time it is totally stock and in great mechanical condition. So I am wondering if he is either dealing with a massive lean condition or cats plugging.

He has new motor sport 24lb per hr injectors "aka ford blue tops" Of which I told him to run at 40psi since ford injectors are rated 24lbs per hr at 39psi and when run at GM's 43.5 psi they deliver around 27lbs per hr.

whats your opinion on this car?

 

[topless82vette]

I also wanted to add that the car see's these excessive coolant temps when the air conditioning is not being used and when the a/c is on it gets much worse.

 

[Hib Halverson]

If the check engine light is not on but the check engine light flashes during bulb check then I'll guess that when the engine is in closed loop, the engine controls can accomodate the 19lb Ford injectors. Shops install Ford injectors because they are cheap.

Is the car is running hot or truly overheating? When does it occur? At ldle. At slow speeds? At high speeds?

IF the system is getting a knock signal, the ECM will retard the spark until the knock starts. If the system is consistently seeing knock retard, that may cause the engine to run hotter. To tell if that problem exists, you need a scan tester which allows real time access to the engine controls' data list.

No stock or near stock L98 needs an injector which delivers 27 lbs per hour.

The first thing to do with that engine is put stock injectors back in. Second, buy a factory service manual. Third, diagnose the engine's problems using the FSM.

Good luck.

 

[topless82vette]

If the check engine light is not on but the check engine light flashes during bulb check then I'll guess that when the engine is in closed loop, the engine controls can accomodate the 19lb Ford injectors. Shops install Ford injectors because they are cheap.

Is the car is running hot or truly overheating? When does it occur? At ldle. At slow speeds? At high speeds?

IF the system is getting a knock signal, the ECM will retard the spark until the knock starts. If the system is consistently seeing knock retard, that may cause the engine to run hotter. To tell if that problem exists, you need a scan tester which allows real time access to the engine controls' data list.

No stock or near stock L98 needs an injector which delivers 27 lbs per hour.

The first thing to do with that engine is put stock injectors back in. Second, buy a factory service manual. Third, diagnose the engine's problems using the FSM.

Good luck.

at idle it maintains it temp but again the fans are running when it is and it stays a bit above 220. On the road it will after awhile see 240 and yes it smells hot and exhibits things related to it really being hot and one of the things is the car loses a considerable amount of power.

My friend has never mentioned the check engine light coming on but says it does come on during during startup for a few seconds so it is working.

Cooling system appears in excellent shape, nice green coolant at all times with no discolration. I drove the car once for two weeks as well as a trip to LAX and back and at a drive thru it would stay at 220 on about a 80 degree day and the fans would be running the whole time yet temps would not drop.

thermostat was replaced, made no difference. Pullies were checked to make sure all turned freely. He says he tried to see if debris was blocking the radiator but he didn't see anything. Yes the front air dam is in place.

this is a 6 speed car to eliminate automatic issues that may be considered.

 

[ken mohr]

I couldn't see much in front of my radiator until I pulled it to have it checked. Filled a 5 gal bucket with road junk. Car has been excellent since.

 

[topless82vette]

I couldn't see much in front of my radiator until I pulled it to have it checked. Filled a 5 gal bucket with road junk. Car has been excellent since.

I notice you have a 1989 corvette. Didn't the radiator mounting change in 1990 or do they suffer the same as the earlier models as picking trash up? I know his car has dual fans and both are running all the time so there should be no reason why it does run hot. By the way no white smoke or any other colors have ever been noticed from the tailpipes. aside from a slight occasional miss the car also seems to run extremly nice up until it starts to get hot.

Do corvettes of the 90 model year suffer from collapsed lower hoses? Could the waterpump be damaged in some way?

I don't think this car is suffering from a clogged radiator at all because he has always changed his coolant every year and maintains the car very well. I believe the car currently has 135k miles

 

[cntrhub]

You have this stoic heat window. Lean is cool up to a point. If the car is falling on it's face, then it sure sounds like a fuel loss.

I would up the injector size to stock, use the stock fuel rail pressure, and try that. Sounds like lean, hot stoic window you are in. Aluminum head may dissipate heat better is helping out with the water leak about to warp your head gasket is heading back to that hot, lean, stoic.

 

[ken mohr]

Sorry You are correct there was a change in 1990

I notice you have a 1989 corvette. Didn't the radiator mounting change in 1990 or do they suffer the same as the earlier models as picking trash up? I know his car has dual fans and both are running all the time so there should be no reason why it does run hot. By the way no white smoke or any other colors have ever been noticed from the tailpipes. aside from a slight occasional miss the car also seems to run extremly nice up until it starts to get hot.

Do corvettes of the 90 model year suffer from collapsed lower hoses? Could the waterpump be damaged in some way?

I don't think this car is suffering from a clogged radiator at all because he has always changed his coolant every year and maintains the car very well. I believe the car currently has 135k miles

 

[G Winter]

I have a 90 . I took the radiator out and was amazed at the amount of leaves , grass and small pebbles that were lodged in the radiator. I cleaned out and straightened the fins and had a marked difference in operating temps. The 90 still seems to have the vacuum cleaner issue.

I think if you had the lower hose collapsing , you would have a severe overheat problem anything over an idle.

Glenn