97 SOHC won't start

[jeff007]

Guys, need some advice on pinpointing a won't start issue.

My son went to pull away after getting gas and the truck even at full throttle just wouldn't go over a couple MPH. He put in in reverse, backed into parking spot and it wouldn't start after that. So after reading posts on this forum all last night and this morning I need help.

What I know:

1) Won't start even when giving full throttle. (fires occasionally)
2) Occasionally backfires through intake
3) Gas smell at tail pipe.
4) 340 code when first happened, cleared it, no further codes have appeared.
5) Checked spark at all plugs with timing light, ok.
6) Checked Cam Position Sensor with meter when cranking and I get AC voltage as the cam lobe passes by.
7) Replaced IAC.
8) Checked vacuum lines.

My next step was to check/replace Crank Position Sensor, and fuel pressure.

It acts like its out of time. As far as I know the 3 parts that deal with timing are the CMP, CKP, and the PCM.

After tonight I'll be out of ideas...Any other suggestions???? I'll repost with results.

Thanks!

 

[jeff007]

Fuel pressure ok

Ok, just tested the fuel pressure...it was at 40 when at key on engine off and stayed around 35-40 when trying to start it. I'm currently replacing the crankshaft position sensor...Still waiting on any suggestions, starting to loose hope!

 

[budwich]

I think you might want to read some of the posts on SOHC timing chain / tensioner replacement...:-( hopefully not your problem but not looking good.

 

[jeff007]

Crackshaft sensor replaced and still no go. What other components effect timing? Camshaft position sensor, PCM... I pulled a sparkplug for the heck of it and as I assumed it was full of gas. Disconnected the battery in hope to reset something in the computer, no joy.

Thanks for the reply Budwich, I just replaced the jackshaft tensioner/cassettes and the front camshaft tensioner/cassettes last month. I'm hoping that the sprocket on the front of the cam didn't come loose. The bad thing is there is no key to keep it in place, just the tension of the cam bolt. Does anyone know how to verify that it is still aligned properly? Would that cause it not to start? Thanks

 

[rbyerman]

Did you do a compression test on it?? This is where I figure out mine was out of time. 4.0 sohc. I can give some types on restting the cam gears for timing. Major pain in the a##.

 

[jeff007]

I have not tried any compression tests, how can that tell me if it is out of time?

 

[rbyerman]

If its out of time it won't build compresson. Another indicator is the motor turns over quicker than before. Thats because its not building any compresson. You mention the cam gears, chains and guides were replaced? Who did this and how many miles ago..

 

[jeff007]

I did the work about 3 weeks ago. I understand what your saying, but the motor doesn't turn over any different than it used to. I can test compression tomorrow. What were you saying about having tips on resetting the cam gears... Thanks again

 

[BrooklynBay]

You mentioned that it smelled like gas, and it was firing through the intake, so that makes me think that the engine is getting flooded. It might be the engine coolant temperature sensor. In my research on this part, WWW.RockAuto.Com is the cheapest (~ $13).

 

[jeff007]

Yea, the engine is for sure getting too much gas...What do you guys think about pulling the fuel pump relay and spraying some starting fluid in the intake to see if it will fire up for a second??? This would eliminate a timing issue correct? Then maybe concentrate on why the computer is wanting to flood the engine with gas. Have you seen the coolent sensor cause engine flooding before?

 

[BrooklynBay]

You could troubleshoot your ECT sensor with the following chart:
Dead Link Removed

 

[jeff007]

I actually just printed that chart from your links, Thanks! I'll check it when I get home. What do you think about the starting fluid / pull fuel pump fuse check to see if it will run???

 

[BrooklynBay]

If you want to test this another way, get a can of Kem, or OTC fuel injector cleaner, and connect it to the fuel port. Disconnect your fuel pump relay, or unplug your inertia switch, and run your vehicle on this chemical. It will idle for a few minutes on this cleaner.

 

[jeff007]

Good idea, I'll try that tonight.

 

[jeff007]

Ok, checked the compression and well there was none....I took the valve cover off and the marks I had used when rebuilding it the first time were not lined up anymore. So, the sprocket or chain slipped and its now out of time. Did you say you had a way to get it back without getting the special alignment tool? Thanks, I'm now going to punch the wall a few times.

 

[jeff007]

Need help getting this cam in alignment, anyone know any tricks? I really can't afford to buy the alignment tool so even if I can get it close enough to run decent then I'm game.

 

[BrooklynBay]

Check this link: http://www.explorerforum.com/forums/showthread.php?t=164327. It has some part numbersof different tools.Maybe AutoZone might have one in their tool loaner program? Maybe somebody on this site could loan you one?

 

[rbyerman]

Jeff007,
I just finished this job on my 98. I went to the dealer and they were kinda enough to let me borrower there tools to do this work. (Paul Huring Ford Hobart, IN. Really good dudes) I couldn't find the tools anywhere else. Did you use the correct tools the first time?? Do you know which cam is out? Let me know the answer to these questions as it will help me explain what to do next. You can also contact me at robert.byerman@mittalsteel.com.

 

[jeff007]

When I did it the first time, I didn't let the cam move so I just put it back exactly the way it was. It ran fine for a few weeks, but then It looks like the chain jumped somehow. The only thing I can think of is that I used the old tensioner (stupid, I know) and it wasn't keeping the chain tight enough. The cam with the problem is on the drivers side.