F I Woes

B Komar · 05-10-2001, 09:37 AM

Hi guys...I have a FI problem. The engine is a 2.0L from a 73 transplanted into a 75. All req'd pieces and parts were brought over from the 73. The engine has about 10,000 miles and has EVERYTHING replaced on it. It sat for 4 years in a garage until I bought it. I went through Kjell's D-Jet trouble shooting and did the following: Timing:ON, Compression:145-150lbs all around, + spark at all cylinders. Pulled injectors & cleaned and checked all...same amt of gas in cup for all injectors, cleaned points on FI contacts in dist., checked all vacuum hoses and connections..all seem good and tight, Fuel pressure is 28-30lbs at cold start injector port on fuel rail. Heres what happens: The engine fires right up but then surges to 3000RPM or so...if I push on the throttle, the engine bogs and will die if I hold it down. I pulled the Manifold Pressure Sensor tubing off at the manifold and plugged the hole with my finger...runs better. I sucked on the hose that goes to the MPS and the RPMS went up. I reconnected the MPS hose the the manifold while the engine was running and the engine instantly died and was more difficult to start after doing so. I honestly thought this would be a no brainer swap considering all that was done to this engine before I bought it and that it was built solely for reliability not performance. Thanks in advance for replies, Brian

Jim Smolka · 05-10-2001, 11:12 AM

Check to see if you have the fuel pressure regulator routed correctly. Just a SWAG.

Jim

bowlsby · 05-10-2001, 11:36 AM

I'd check into your MPS further.

Does it hold vacuum? (~15 inches)
Do the coils have proper resistance value? (check at inner two/outer two prongs.

B Komar · 05-10-2001, 08:00 PM

I did not remove or change the fuel pressure regulator, so its in the same place that it was when it was driven/running before. I did try putting another MPS on (from a 1.7L) and had the same problem. If this was a vacuum leak somewhere in there, would the engine bog when I push on the accelerator? Is there another place that there would be a big leak thats not covered in Kjells article? I did not remove the intake runners from the head like the article suggests, is there any other way to check the runner boots with all that still on? On my other 2.0 with a crappy progressive carb, there are hose clamps on the boots...this one doesn't have them..does it need them? Thanks, Brian

SteveStromberg · 05-11-2001, 04:54 AM

I had a problem like yours on a 74 2.0 it turn out to be a broken wire in the FI harness. Get out the multi meter to check the continuity of the wires. Steve

bowlsby · 05-11-2001, 09:32 AM

And Steve Stromberg knows where to get a new FI harness if you happen to need one...8^)

pbanders · pbanders's Garage

Hard to say what's wrong, just some guesses. Did you check your head temperature sensor resistance? Don't just check it at the sensor, check it at the ECU plug to make sure you have a good wiring harness. If you get an open, that could be the problem - regardless, it's got to be fixed. Also check some simple stuff - ECU connector properly seated, MPS holds vacuum and has proper coil resistances, etc.

Brad Anders

George Simmons · 05-13-2001, 06:48 PM

You've got a vacuum leak. Check the hose connection at the bottom of the throttle body.

TimW · 05-14-2001, 07:39 AM

I had very similar symptoms with my recently transplanted ’74 2.0L. It would idle hunt around 2800 RPM, and under power would bog/sputter above 3500RPM to redline.

I attribute the problems to a vacuum leak. Why? That was one of the first things I checked, renewing where needed, and the problems went away.

Just my experience...but as you can read it could also be any number of other things.

B Komar · 05-14-2001, 09:28 AM

Thanks guys, I haven't had much time to go out and play with it, and quite honestly, I needed a little time away from it due to the extreme discouragement after doing all I have done and still no maiden voyage. It really does seem like a vacuum leak. I am not very well versed in checking resistance etc.(read: I dont know how). I can check continuity though. I am somewhat confident that the electronic (electric) equipment is intact and working. All was new 10000 miles ago and it ran OK when I picked it up in Seattle. I'm sure it is something simple somewhere. I am glad I went through all the diagnostics that I have, it gives me more confidence that the purchase of this engine/car was a good one. I will do more hunting this week. I'm sure glad this isn't my only mode of transportation!