# Hesitation and Noise...



## Terran200sx (Dec 30, 2004)

This happens especially when the car is cold, i.e first start for the morning. There is a loud "clak"-ing noise coming from the engine compartment-the valve cover. It can also be heard if i turn off all the music or if i have the hood open and manually rev it up. Also, between 2k - 3k theres hesitation on accel and at around 3k, there's vibration and a feeling of more hesitaiton. Any ideas?


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## rogoman (Dec 16, 2004)

First make sure the motor oil is at the full mark. If that's OK, then the oil pressure is probably very low that's causing the noise; the oil pump may be worn.


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## Terran200sx (Dec 30, 2004)

rogoman said:


> First make sure the motor oil is at the full mark. If that's OK, then the oil pressure is probably very low that's causing the noise; the oil pump may be worn.


MY mech thought that my valves may need to be adjusted.


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## rogoman (Dec 16, 2004)

Terran200sx said:


> MY mech thought that my valves may need to be adjusted.


I'll assume it's your 1990 240. If so, the valves are non adjustable; hydraulic lifters are used.

The hydraulic lifters may be worn but in most cases it's because of very low oil pressure.


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## Terran200sx (Dec 30, 2004)

OK, expain the hesitation on acceleration and vibration and how oil pressure would affect that.


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## xs04298 (Oct 28, 2005)

friction, metal rubbing metal, drags the engine down, and untill you get the RPM fast enough to overcome this, it'll be laggy, untill it starts heating up internal engine parts and causing damage, to say hydrolic lifters. Its just one possability though..


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## Terran200sx (Dec 30, 2004)

xs04298 said:


> friction, metal rubbing metal, drags the engine down, and untill you get the RPM fast enough to overcome this, it'll be laggy, untill it starts heating up internal engine parts and causing damage, to say hydrolic lifters. Its just one possability though..


IT seems to bog down around 2.5k then go right back up again.


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## rogoman (Dec 16, 2004)

Terran200sx said:


> OK, expain the hesitation on acceleration and vibration and how oil pressure would affect that.


It looks like you've got more then one problem. Like I said in a previous post, the claking sound may be caused by low oil pressure.

The hesitation and vibration may be caused by several things:
1 - bad MAF
2 - fuel delivery problem
3 - bad spark plugs
4 - uneven compression
5 - major vacuum leak


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## Terran200sx (Dec 30, 2004)

> 1 - bad MAF


How do i check this?


> 2 - fuel delivery problem


Ditto.


> 3 - bad spark plugs


I just changed them like 3k miles ago


> 4 - uneven compression


I know how to check this.


> 5 - major vacuum leak


This might also explain the random bad idle i thought was due to IAS valve.


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## rogoman (Dec 16, 2004)

1 - bad MAF
Here's a procedure from the FSM:









2 - fuel delivery problem
An easy quick way to test the fuel pump and filter is to disconnect the fuel hose from the top of the fuel filter and insert a long length of spare hose into the top of the fuel filter with the other end draped over the fender going into a catch can placed on the ground. Now turn the ignition key to the run position but DO NOT START THE ENGINE. You should see fuel going into the can at a good rate for several seconds.

You can do further testing by measuring the fuel pressure; connect a temporary fuel pressure gauge between the fuel filter and the fuel log with a tee connector.
Fuel pressure with regulator vacuum hose connected: 34 psi
Fuel pressure with regulator vacuum hose disconnected: 43 psi


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## Terran200sx (Dec 30, 2004)

> 1 - bad MAF


It's around 1.47 - 1.49 at idle, a little high, but not too far off.



> 2 - fuel delivery problem


Looked at the injectors, wiggled each one, the engine shook on like 2 of the 4 injectors when i wiggled the harness. Yeah. How much is that to fix?


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## Terran200sx (Dec 30, 2004)

Where can i get a new harness, the factory Parts only had 3 choices, 2 for 476 and 1 for 126?


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## rogoman (Dec 16, 2004)

The harness connectors at the injectors might be just be loose or dirty or have oxidation on them.


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## Terran200sx (Dec 30, 2004)

rogoman said:


> The harness connectors at the injectors might be just be loose or dirty or have oxidation on them.


yeah, what's the fix?


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## rogoman (Dec 16, 2004)

The fix is cleaning the clip or if it's loose, use a pair of pliers to squeeze the clip together.


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## Terran200sx (Dec 30, 2004)

rogoman said:


> The fix is cleaning the clip or if it's loose, use a pair of pliers to squeeze the clip together.


Excuse my stupidity, but how does the injector clip come off?


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## SonsofWisdom (Mar 29, 2004)

I'm having similar issues with my 89 240...the coating over the wires is brittle, the connectors dust boots are gone or breaking off. 

When idleing I could wiggle the connectors and I could get a miss.

There should be a metal clip that holds the connector in place...if it's gone then that connector can come off easily...otherwise just from vibration...

I think the issue with my wireing is an oil leak over LONG time...oil can make those components brittle (wires, dust boots especially)


I am not keeping this engine so I'm not going to fix this problem, it will be fixed when I get a new wire harness from the engine I choose to put in.


Someone was selling a 240 not to long ago and the valve timing on it was off (suprised it didn't doink a valve). I'm pretty sure they had the head off of it...and they also screwed with ignition timing...this may not be your problem...check ignition timing...valve timing...hmm...fun one to check


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## Terran200sx (Dec 30, 2004)

SonsofWisdom said:


> I'm having similar issues with my 89 240...the coating over the wires is brittle, the connectors dust boots are gone or breaking off.
> 
> When idleing I could wiggle the connectors and I could get a miss.
> 
> ...


No, i too, had an oil leak + Heat that caused the harness to crack and brittle, although i do think the connectors still should get clean/repinned as i need the engine for a few thousand more miles before i go RB.


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## SonsofWisdom (Mar 29, 2004)

HA HA...good ol wiring issues. SO much fun. I had a power flow problem to my fuel pump as well as the injector problem (that was fun figuring out).

All I did to fix it was disconnect and clean every connector...every...connector...from the battery to the relay to the ignition switch to the fuel pump...put some dialectric grease after cleaning and reconnected 'em all...problem hasn't come back so far except for the injector prob as I didn't clean them until later.

But also, I don't drive my 240 so the wires don't wiggle loose


Good luck on your search, I hope you can get some good help...sorry I wasn't much


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## Terran200sx (Dec 30, 2004)

The vibration around 65 gets worse witht he more weight that's in the car. Is that the same problem?


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