Does this sound like a plugged exhaust system?

[Afboy143]

Hey guys,
I am trying to help a buddy of mine out. She has been having starting problems on her truck. Sometimes it starts, sometimes it gets ready to start then just doesn’t. She took it to Jiffy Lube to get it checked out (I know- not the best but I am going off info she gave me) and they told her the problem is an exhaust problem and she needs to take it to Midas (nice of them to refer her elsewhere).

Now I’ve never dealt with an exhaust problem before because on every vehicle I ever had, the first thing I change out is the exhaust system. The truck has over 200k miles on it so I can see where a clogged cat or muffler would come into play. Would a clogged cat or muffler cause it not to start or only start periodically? Should I disconnect the exhaust at the manifolds and test it?

 

[Dan Whitaker]

I think they are full of **** myself.

When it acts up have you tried pressing on the accelerator to see if it starts?

 

[Afboy143]

Lol!!!

Yes, some times it works, sometimes it doesn’t. It’s weird! I did her oil and fuel filter the other day but that didn’t help. Fuel pressure seems to be fine. Sometimes it starts right up, some times it takes a bit, sometimes it just doesn’t start period. It’s weird

 

[Dan Whitaker]

Lol!!!

Yes, some times it works, sometimes it doesn’t. It’s weird! I did her oil and fuel filter the other day but that didn’t help. Fuel pressure seems to be fine. Sometimes it starts right up, some times it takes a bit, sometimes it just doesn’t start period. It’s weird

I had a '92 Cougar that acted like that sometimes. The only difference was it would stall at a light somtimes was well. If I pressed on the accelerator while cranking it would start. I cleaned the MAF and it solved my problem.

 

[Afboy143]

Hmm- guess that goes to show sometimes the easiest thing can be the problem. I have MAF cleaner at hope. I’ll see about shooting some of that over her MAF to see if it helps. Thank you sir

 

[Curtis]

Hmm- guess that goes to show sometimes the easiest thing can be the problem. I have MAF cleaner at hope. I’ll see about shooting some of that over her MAF to see if it helps. Thank you sir

I had similar problems not too long ago. Rough start, if it did start. Very bad idle and sometimes were die.

I cleaned the MAF and tested it too by blowing into it while the truck was running. It stumbled when I would blow in it so I know something was working.

At that time, it was throwing a code for insufficient cat flow, and I too thought the cats were clogged.

After a new thermostat and cleaned MAF, its been fine since - knock on wood.

 

[Afboy143]

I had similar problems not too long ago. Rough start, if it did start. Very bad idle and sometimes were die.

I cleaned the MAF and tested it too by blowing into it while the truck was running. It stumbled when I would blow in it so I know something was working.

At that time, it was throwing a code for insufficient cat flow, and I too thought the cats were clogged.

After a new thermostat and cleaned MAF, its been fine since - knock on wood.

Wow I saw the email on this and got confused because my name is Curtis lol

So what made you think it was the thermostat? Was it overheating?

 

[Curtis]

Wow I saw the email on this and got confused because my name is Curtis lol

So what made you think it was the thermostat? Was it overheating?

Another Curtis!.. I have not met many LOL

yea my temp was maxed on the gauge but the truck did not act hot. No steam, bubbling noises, radiator was cool etc. So for $5 I switched it out.... One of those "Do cheap things first" ideas.

 

[Afboy143]

yeah I know! Most I know start with K if I do.

Yeah I am just having trouble starting. So two posts now directing toward the MAF. Guess I need to get some cleaner on it

 

[ranger7ltr]

You can test the temp before and after the cats...

When you get the truck running if you have an IR thermometer...After I installed my new engine, I checked all four cats and the muffler and found the front 2 were hotter at the front of the cats than at the back of them... The 2 cats that were in series were hotter at the outlets than the inlets and the muffler I didn't bother testing...

I once bought a Merkur Scorpio that did not run and found the O2 wiring had been cut by the previous owner to try to make the engine run richer...By the time I bought it, the front convertor was so melted the only way the engine ran was to hold the throttle to almost wide open and then it only ran at about 600 rpm...

I dropped the exhaust in front of the front cat and started the engine with no throttle after fixing the o2 wiring and the exhaust open...

When the truck does start, how does it run? Does it feel like it takes excessive throttle to drive or does it feel "normal"? And when it doesn't start, what is the fuel pressure level?

 

[Afboy143]

When you get the truck running if you have an IR thermometer...After I installed my new engine, I checked all four cats and the muffler and found the front 2 were hotter at the front of the cats than at the back of them... The 2 cats that were in series were hotter at the outlets than the inlets and the muffler I didn't bother testing...

I once bought a Merkur Scorpio that did not run and found the O2 wiring had been cut by the previous owner to try to make the engine run richer...By the time I bought it, the front convertor was so melted the only way the engine ran was to hold the throttle to almost wide open and then it only ran at about 600 rpm...

I dropped the exhaust in front of the front cat and started the engine with no throttle after fixing the o2 wiring and the exhaust open...

When the truck does start, how does it run? Does it feel like it takes excessive throttle to drive or does it feel "normal"? And when it doesn't start, what is the fuel pressure level?

Merkur Scorpio... sweet!

Once it gets started, it runs fine! I changed the fuel filter and she said it felt like it had more power which was weird- but once its started she said everything is good. It idles just fine, does sputter or stall out until turned off. It's weird. I didn't check the fuel pressure which I should since i have a guage

 

[Afboy143]

Little update to all this

She had to get a ride this morning- truck wouldn’t start. She described the symtoms as follows

Push down gas pedal, Turn key, attempts to start but can’t so it just starts clicking. Tries again, same thing. She said usually the first key turn is the best shot- after that it goes down hill. Today it just wouldn’t do anything so she had to get a ride. The battery is new, so I ruled this out. Due to the clicking, I’m thinking it’s electrical somehow- somewhere. Also, since the start is best at the first key turn, that’s when volts are highest? But why would the gas pedal play a role? This is driving me nuts. Any suggestions?

 

[ranger7ltr]

Hmmm...Sounds like a challenge..

The pedal to the floor actually shuts off fuel flow to the engine; It acts like you have a flooded engine and opened the throttle to clear the fuel with excess air...

I am wondering if the fuel pump is getting to the point of being intermmitently bad...Sometimes it runs, sometimes it doesn't, sometimes it only puts out 10-20 psi...I installed a new tank and pump in March thanks to the original one being rusty...The pump seemed fine until about a month ago when I noticed the pressure would start dropping as I would accelerate the truck,,,The harder I accelerate, the further the pressure dropped...And my truck has the returnless system that runs at 65-72 psi and until this had never dropped at all...If the truck is a 1999 or newer this spec applies as well; 1998 and older the fuel pressure spec is 30-43 psi, nominal being 35-40 psi...And the older trucks have a vacuum fuel pressure regulator which will vary the fuel pressure by the vacuum signal...The newer trucks have the regulator in the tank and there is not variation on the fuel pressure by load; the PCM varies the injector pulsewidth to compensate...

A week after that started, on a hot damn Saturday morning, the pump decided to only output 20 psi in a Walmart parking lot...It would run for a few seconds roughly then die...The fuel pressure gauge confirmed that...Towed it home, dropped the tank, looked at the new pump and found the power connector was charred and the terminals black...

If the truck is clicking when starting it might have a solenoid or cabling issues...

Replaced the defective pump with a spare new pump, reinstall the tank and truck is running perfectly again...

And I loved my Scorpios...Bought both as non-running vehicles and fixed the first one and drove it 6 years with no issues...Converted the second one to V8 power and wish to God i had kept both of them...They were really ahead of the times vehicle wise...

 

[Afboy143]

The pedal to the floor actually shuts off fuel flow to the engine; It acts like you have a flooded engine and opened the throttle to clear the fuel with excess air...

I am wondering if the fuel pump is getting to the point of being intermmitently bad...Sometimes it runs, sometimes it doesn't, sometimes it only puts out 10-20 psi...I installed a new tank and pump in March thanks to the original one being rusty...The pump seemed fine until about a month ago when I noticed the pressure would start dropping as I would accelerate the truck,,,The harder I accelerate, the further the pressure dropped...And my truck has the returnless system that runs at 65-72 psi and until this had never dropped at all...If the truck is a 1999 or newer this spec applies as well; 1998 and older the fuel pressure spec is 30-43 psi, nominal being 35-40 psi...And the older trucks have a vacuum fuel pressure regulator which will vary the fuel pressure by the vacuum signal...The newer trucks have the regulator in the tank and there is not variation on the fuel pressure by load; the PCM varies the injector pulsewidth to compensate...

A week after that started, on a hot damn Saturday morning, the pump decided to only output 20 psi in a Walmart parking lot...It would run for a few seconds roughly then die...The fuel pressure gauge confirmed that...Towed it home, dropped the tank, looked at the new pump and found the power connector was charred and the terminals black...

If the truck is clicking when starting it might have a solenoid or cabling issues...

Replaced the defective pump with a spare new pump, reinstall the tank and truck is running perfectly again...

And I loved my Scorpios...Bought both as non-running vehicles and fixed the first one and drove it 6 years with no issues...Converted the second one to V8 power and wish to God i had kept both of them...They were really ahead of the times vehicle wise...

I read about your fuel pump issue on a personal problem I posted. I plan on changing my pump and gas tank soon

On her truck, sounds like a viable option. Im beginning to tell her to bite the bullet and start looking for another vehicle option. LOL

I am wondering why the place she went to is telling her it's an exhaust problem. It's driving me crazy ! So with needing to pump the gas, that's a sign of fuel pressure not getting to where it needs to be, correct?

 

[Dan Whitaker]

I read about your fuel pump issue on a personal problem I posted. I plan on changing my pump and gas tank soon

On her truck, sounds like a viable option. Im beginning to tell her to bite the bullet and start looking for another vehicle option. LOL

I am wondering why the place she went to is telling her it's an exhaust problem. It's driving me crazy ! So with needing to pump the gas, that's a sign of fuel pressure not getting to where it needs to be, correct?

Rippy Lube doesn't know how to change oil. How do expect them to know what's wrong with it :