Hello, I have a 96 f250 7.5l with the stock cali Maf sequential fuel injection. Do I have a MAP sensor and where is it located? Could somebody link me a photograph. I can't seem to find it in my chiltons manual as it doesn't seem to show the 96 cali emissions model.

 

If it's a MAF vehicle, you don't have a MAP sensor.

 

Your Cali. emission truck is not very common. Very few manuals, if any, will have information for your specific model/engine/MAF combination. Why are you trying to find a MAP sensor?

 

Thank you I had a feeling because it had a MAF it wouldn't have a MAP. Just wanted to ask because I have had vehicles in the past that had both.

The reason I was looking for it was I have been running lean and pinging at part throttle, even after replacing all the broken vacuum lines. I'm certain there is still a vacuum leak somewhere.

Do the throttle body/intake gaskets ever leak as they get older?

Also should the EGR on my vehicle hold vacuum? whenever I hook up my vacuum pump it works (stalls the vehicle/drastically lowers idle speed) but it won't hold vacuum for more than 3 secs.

It seems to only ping once the engine is fully warm. It runs great until its warmed up, then it starts pinging like mad at part throttle.

 

I don't know if it's common, but my 135,000+ mile truck has a lower intake manifold gasket leak.

 

Well I'm at 150k+ so I'll check mine out.

 

IIRC the EGR should hold a vacuum for longer than 3 seconds. Sounds like a punctured diaphragm to me. This is assuming you are applying vacuum directly to the EGR.

Yes the intake/throttlebody gaskets can crack due to age, heat, etc.

 

I thought it should hold vacuum for more than 3 seconds, and yes this was when I directly hooked up to the egr. Is it possible to just replace the diaphram or do I possibly need a new egr valve?

 

I have never investigated the possibility of just replacing a diaphragm. I have always replaced the entire assembly.

 

Well I rechecked my egr valve and it actually does hold vacuum, I don't know how I messed that up *shrug*.

I also checked my initial timing which is supposed to be 10 and at a certain angle it looked 10 but another angle it looked to be about 12-13. so what angle should I be looking at it from? Sorry if that sounds dumb.

 

Fuel Injection Technical Library » Setting the timing

 

Thank you again,